# Exercise caution: some methodological and theoretical considerations when examining improvements in attentional selectivity following exercise

Nadège Rochat, Pierpaolo Iodice, Ludovic Ferrand, Benjamin Parris, Maria Augustinova

<figure><img src="image_1.png" /></figure>

## To cite this version:

Nadège Rochat, Pierpaolo Iodice, Ludovic Ferrand, Benjamin Parris, Maria Augustinova. Exercise caution: some methodological and theoretical considerations when examining improvements in attentional selectivity following exercise. International Review of Sport and Exercise Psychology, 2024, pp.1-22. 10.1080/1750984X.2024.2431506. hal-04808026

HAL Id: hal-04808026

https://hal.science/hal-04808026v1

Submitted on 27 Nov 2024

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

<figure><img src="image_2.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
Some methodological and theoretical considerations when examining improvements in
attentional selectivity following exercise

Nadège Rochat¹,²,³*, Pierpaolo Iodice²,⁴, Ludovic Ferrand⁵, Benjamin A. Parris⁶, and Maria Augustinova¹*

¹Normandie Université, UNIROUEN, CRFDP, UR 7475, 76000, Rouen, France

²Normandie Université, UNIROUEN, CETAPS, UR 3832, 76000, Rouen, France

³Université Clermont Auvergne, ACTé, UR 4281, 63000 Clermont-Ferrand, France

⁴Le Mans Université, MIP, UR 4334, 72000 Le Mans, France

⁵Université Clermont Auvergne, CNRS, LAPSCO, UMR 6024, 63000 Clermont-Ferrand,

France

⁶Department of Psychology, Bournemouth University, Poole, UK

*Corresponding authors:

Nadège Rochat

Université Clermont Auvergne

Laboratoire Activité, Connaissance, Transmission, Éducation (ACTé, UR 4281),

INSPÉ Clermont-Auvergne, 36 avenue Jean-Jaurès CS 20001, 63407 Chamalières Cedex,

FRANCE

E-mail: nadege.rochat@uca.fr

Phone: + 33 473 318 769

or

Maria Augustinova

Université de Rouen Normandie

Le Centre de Recherches sur les Fonctionnements et Dysfonctionnements Psychologiques

(CRFDP, EA 7475),

UFR SHS – Bâtiment Freinet, Place Emile Blondel, 76821 Mont Saint Aignan Cedex,

FRANCE

E-mail: maria.augustinova@univ-rouen.fr

Phone: + 33 473 406 257

Fax: + 33 473 406 114

Word count (main text and subheadings): 6186
45 **Abstract**

46 Numerous studies investigating the effects of a given laboratory or field intervention
47 on attentional selectivity have evidenced their (positive) findings with improved performance
48 in the Stroop task. In contrast to conclusions drawn in these studies, the present paper argues
49 that the extent to which this improvement actually reflects an attentional/inhibitory boost is
50 still relatively unknown. To evidence this claim, this paper first delimited conditions under
51 which Stroop performance indicators can directly measure selective attention and its changes.
52 It then assessed the use of these indicators in a specific and exemplary body of translational
53 research investigating the link (correlational or causal) between physical activity/exercise and
54 attentional selectivity with a result that only nine past studies (out of 52) actually used
55 relevant indicators of physical activity/exercise-related changes in selective attention. The
56 narrative review of these nine studies highlighted a substantial gap between what this body of
57 research shows and the conclusions it draws. To mitigate this gap that is likely to concern all
58 types of research aimed at boosting attentional selectivity, the paper also provided practical
59 guidelines to allow future studies employing the Stroop task to draw more theoretically and
60 empirically grounded inferences about the effects of any intervention on attentional
61 selectivity.
62

62

63 **Keywords**

64 Inhibition; Measure of interference; Physical activity; Selective attention; Stroop task
**Introduction**

Current societal changes – including population ageing, post-pandemic adoption of work-from-home policies and excessive exposure to screen time – raise concerns about individuals’ cognitive abilities and their preservation and replenishment. Therefore, unsurprisingly, there is a growing body of research aimed at identifying lifestyles or practices that are associated with enhanced cognitive abilities (e.g., level of physical fitness, amounts of daily mindfulness meditation practices). Additionally, interventions that effectively preserve or even boost individuals’ cognitive functioning – either immediately (e.g., a short exposure to nature) or after a longer period of time (e.g., several weeks of a cognitive training program) have been investigated.

Regardless of both the type of intervention under scrutiny (e.g., physical activity, mindfulness meditation, exposure to nature, cognitive training etc.) and the nature of its link to cognitive abilities (i.e., correlational vs. causal), this type of translational research frequently involves the use of selective attention tasks such as the Stroop task (Stroop, 1935). The Stroop task is sometimes included in a larger battery of cognitive tests or supplemented by other standardized or standard cognitive tasks (see e.g., Cremen & Carson, 2017 for a discussion), but frequently, the efficiency of the key components of cognitive functioning such as “interference control”, “selective attention and/or the inhibition it entails” or “executive functions” (i.e., a supraordinate family of cognitive processes that encompasses attentional control and inhibition it entails) are assessed by the means of the Stroop task alone (see e.g., Buck et al., 2008; Ishihara et al., 2018; and Best et al., 2014 for examples of these respective endeavors). This is not surprising since the standard (i.e., color-word) Stroop task is generally considered the “gold standard of attention measures” (MacLeod, 1992) as well as “a prototypical inhibition task” (Miyake et al., 2000, p. 57). But at the risk of stating the
obvious, it is important to remember that the deployment of this task itself, does not guarantee
that this gold standard is met.

To provide further and hopefully more explicit grounds for the necessity of this
reminder, the present paper first attempts to delimit conditions that are the most favorable for
measuring selective attention (section “Measuring attentional selectivity in the Stroop task”)
and its changes (section “Assessing the link between any given intervention and attentional
selectivity measured in the Stroop task”). Building on Furley and colleagues (2023 in this
journal), the paper then assesses the extent to which these specific measurement conditions
are met in research examining the link between physical activity/exercise and attentional
abilities (see Table 1 and Tables 1S and 2S in Supplementary Materials for all assessed
studies). As a result of this endeavor, this section (“Assessing the link between physical
activity and attentional selectivity measured in the Stroop task”) argues that there is a
substantial gap between what this specific body of research shows and the conclusions it
draws about the attentional benefits of physical activity/exercise. But because this gap is not
limited to this particular body of research, and rather concerns all types of translational
research aimed at boosting selective attention and/or the inhibition it entails, the paper then
provides practical guidelines designed to mitigate this gap (section “Practical guidelines for a
more direct measure of selective attention in the Stroop task”). Indeed, Furley and colleagues
(2023 in this journal) have argued that in addition to adopting a more mechanistic approach
(see also e.g., Diamond, 2020; Smid et al., 2020), this mitigation largely requires progress in
conceptualization and measurement of indicators used to appraise intervention-related
changes in cognitive abilities (see also e.g., Cremen & Carson, 2017). In line with this latter
idea – echoing directly an ongoing debate in the Stroop literature (e.g., Algom et al., 2022;
Chajut & Algom, 2019; Parris et al., 2022; Parris et al., 2023) –, the most important goal of
this paper is to help future studies using the Stroop task to make more theoretically and
114

empirically grounded inferences about the effects of any given intervention on attentional selectivity and the inhibition it entails.

115

116

117

## Measuring attentional selectivity in the Stroop task

118

Given the number of studies that have employed the Stroop task since its inception in 1935 by John Ridley Stroop (1897-1973), it is no surprise that many different variants of the original task have been employed. Still, whether it is administered in a paper/pencil (i.e., list) or in a computerized (i.e., item-by-item) form, the standard (i.e., color-word) Stroop task (Stroop, 1935) requires individuals to identify – as quickly and as accurately possible – the color of the font in which a word is presented whilst ignoring the meaning of the word itself. Despite these instructions, individuals experience difficulties identifying the ink color of a word when it denotes a different color (e.g., “BLUE” presented in red ink, hereafter *BLUE*<sub>red</sub>).

119

120

121

122

123

124

125

126

127

128

This is because “The conflict between the relevant (color of the word) and irrelevant (name of the word) dimensions of the stimulus on *incongruent trials* presents a particularly difficult task for the selective attentional system (Spieler et al., 1996, p. 461; italics added).”.

129

Consequently, color-identification of incongruent trials is substantially longer and more prone to errors compared to a relevant baseline. It is this difference – called *the Stroop effect* or the *Stroop interference effect* – that is used to assess the efficiency of selective attention with a larger magnitude of Stroop interference being equated with lower attentional selectivity and lower interference control it entails (e.g., Chajut & Algom, 2019; MacLeod, 1998; Parris et al., 2022).

130

131

132

133

134

135

But before elaborating further on conceptual difficulties surrounding this measure of selective attention, it seems important to recall some basic methodological principles, starting with the fact that both speed (typically measured by RTs) and accuracy (typically measured by errors-rates), need to be considered simultaneously to understand performance in the

136

137

138
Stroop task (Heitz, 2014; Vandierendonck, 2021), unless the time to complete a given list of items is kept constant<fnref n="1" />. Indeed, when only one of these two indicators is considered (i.e., measured, analyzed and/or reported; see Table 2S in Supplementary Materials for examples of this selective consideration in sport and exercise research using the Stroop task), it is impossible to exclude the possibility that the reported speed is not traded for accuracy, nor inversely, that the reported accuracy is not traded for speed. Simply put, while the elimination of this tradeoff is important for the interpretation of processes driving the Stroop effect itself, and/or its changes (see here below), simultaneous consideration of both indicators allows the verification that the task instructions – emphasizing both accuracy and speed (see above) – were followed.

Another basic, yet important methodological aspect to bear in mind is that the observed levels of speed and accuracy must be assessed with respect to a relevant baseline (again see Table 2S in SM for examples of sport and exercise research where this type of comparison is clearly missing). Now, selecting an appropriate baseline in the Stroop task is itself non-trivial (see Parris et al., 2022 for discussion; see Figure 1 for a diagrammatic representation of the complexity of baseline selection). For example, color-congruent trials (e.g., *BLUE<sub>blue</sub>*, first introduced by Dalrymple-Alford and Budayr (1966, Exp. 2), have become a popular baseline condition against which performance on color-incongruent (i.e., conflict or interference) trials is compared (see Table 1S in SM for examples of this type of baseline in sport and exercise research). But it is necessary to understand that the ink color of color-congruent items is identified reliably faster than that of color-neutral trials (e.g., non-color word “DEAL” presented in red ink, *DEAL<sub>red</sub>*, Dalrymple-Alford & Budayr, 1966, for the first demonstration) – leading to an effect later termed as *facilitation* (Dalrymple-Alford, 1972).

<footnote n="1">¹ This case in some paper/pencil (i.e., list) versions of the Stroop task where the time to complete a given list is restricted to 45 sec for instance (see e.g., Tables 1) for examples of such versions of the Stroop).</footnote>
Consequently, without the inclusion of color-neutral trials, the measure of the Stroop effect as a difference between color-incongruent and color-congruent trials (e.g., $BLUE_{red} - BLUE_{blue}$) – sometimes referred to as the Stroop congruency effect or the overall Stroop effect – confounds the interfering effect experienced on color-incongruent trials with the opposing effect of facilitation on color-congruent trials. It represents therefore “(...) the sum of facilitation and interference, each in unknown amounts” (MacLeod, 1991, p.168). Moreover, when including a color-neutral baseline, it is clear that their magnitudes are often asymmetrical (with facilitation being generally smaller than interference, MacLeod & MacDonald, 2000, see also e.g., Smith & Ulrich, 2023 for a more general discussion of this “violation of the midpoint assumption” in several other conflict or interference tasks).

Furthermore, facilitation on color-congruent trials is known to increase when experimental setups encourage contingent associative learning between words and responses, or words and colors, as is the case when using equal proportions of color-congruent and color-incongruent items (see Hasshim & Parris, 2021; Schmidt, 2013 and see Table 1 and Tables 1S and 2S in Supplementary Materials, SM for examples of sport and exercise research using this equal proportion). Since the numbers of incongruent and congruent stimuli are equal, the word e.g., *red* more commonly predicts the response red than any other color. This is because there are only four possible congruent stimuli (assuming four response colors). If congruent trials are as numerous as incongruent trials (e.g., 72 of each trial type), each congruent stimulus must be repeated more times than each incongruent stimulus. This contingency between the word and response leads to faster responses for the contingent congruent trials.

To sum up, the magnitude (or amount) of *interference* produced by color-incongruent trials – considered as prime indicator of attentional abilities – cannot be reliably assessed when using color-congruent trials as a unique comparison baseline (see Figure 1, and see
187

Algom et al., 2022; Algom & Chajut, 2019; MacLeod, 1991; Parris et al., 2022; Quétard et al., 2023, for discussions of this issue).

188

189

190

Insert Figure 1 near here

191

Figure 1. Contribution of facilitation, lexicality cost and interference effects to the overall Stroop/congruency effect.

192

193

*Note.* Original figure based on data from Augustinova et al. (2019) reported with Verbal (Panel A) and Manual (Panel B) response modality.

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

In order to measure interference on color-incongruent trials independently of facilitation on color-congruent trials, some studies used either color-patches or colored dots, as well as rows of signs or letters (e.g., colored Xs) as a comparison baseline (see Table 1 for examples). As an anecdote, to derive interference – central in his work – J.R. Stroop himself, used rows of colored Sanskrit swastikas as a comparison baseline (Stroop, 1935, Exp.3, see also Exp.2 for the use of full squares). However, even with these different choices, the magnitude of interference is still potentially overestimated (see Brown, 2011 for an ample demonstration), since a row of letters (e.g., “XXXX”), is not a word which, unlike “DEAL” for instance, has a meaning. As a result, color identification of color-neutral non-word items (e.g., XXXX<sub>red</sub>) is faster than that of color-neutral word items (e.g., <u>DEAL</u><sub>red</sub>). This effect, known as *lexicality cost* or *neutral word interference* (e.g., Brown, 2011), is of substantially greater magnitude (i.e., conflates magnitude of Stroop interference even more) when the Stroop task administered with vocal as opposed to manual responses (see Figure 1).

Therefore, when the magnitude of interference produced by color-incongruent trials (i.e., the prime indicator of attentional abilities) is under scrutiny, a color-neutral baseline consisting of non-color words (e.g., *DEAL*<sub>blue</sub>) seems to be the most appropriate baseline. This
212 is because the lexicality cost of non-color related words is identical to that observed on color- 213 incongruent words, and as mentioned above, they also allow the derivation of interference 214 independently of facilitation. In conclusion, non-color *words* (as opposed to other types of 215 color-neutral baseline items) permits the most accurate estimation of interference produced by 216 color-incongruent items.

217 Despite the more ideal nature of the non-color word baseline, it is still seldom used 218 and not just in research examining the link between physical activity/exercise and attentional 219 abilities considered below. In light of Cremen and Carson's (2017) argument that in 220 intervention studies standardized tests are *de rigueur*, perhaps the most striking example is the 221 fact that the standardized Stroop tests used in clinical practice (e.g., Bayard et al., 2011; 222 Troyer et al., 2006) do not currently use non-color word baseline to derive interference<fnref n="2" />.

223 Consequently, in what follows, the *Stroop interference effect* is defined more loosely as the 224 difference in speed and accuracy between color-incongruent and any kind of color-neutral 225 trial (e.g., *BLUE*<sub>red</sub>–*DEAL/XXXX*/■■■■<sub>red</sub>). In contrast, a difference between color- 226 incongruent and color-congruent trials (e.g., *BLUE*<sub>red</sub>–*BLUE*<sub>blue</sub>) – confounding interference 227 and facilitation – will be referred to as the *overall Stroop effect*. Finally, whenever both are 228 being evoked, the umbrella term of *Stroop effect* will be used.

229

230 Assessing the link between any given intervention and attentional selectivity measured 231 in the Stroop task

<footnote n="2">² In these tests, non-color words are in fact included, but color-naming on these trials is compared to that on non-word trials (e.g., colored dots for instance). This latter measure of “low interference” is different from “high interference” condition (i.e., performance difference between color-incongruent words and dots). As explained above, significant “low interference” constitutes indeed an empirical demonstration of *lexicality cost* or *neutral word interference* (e.g., Brown, 2011) discussed above. Most importantly, the “genuine” interference (i.e., performance difference between color-incongruent words and non-color words that is free of lexicality cost) is not computed.</footnote>
As already mentioned, to test the merits of any given intervention – including physical activity/exercise – one can assess the extent to which this intervention is either associated with attentional abilities or causes their improvement. In the former case, the test is correlational and requires that both the levels of Stroop performance and of a given intervention or practice (e.g., level of physical fitness) are measured. In order to claim that higher physical fitness for instance is associated with better attentional selectivity, it is the magnitude of Stroop interference (preferably measured with color-neutral words trials as baseline) that needs to be negatively correlated with physical fitness (see section above). Said differently, in light of the conceptual and methodological issues raised in the previous section, negative correlation between levels of physical fitness and the overall Stroop effect (or simply RTs and/or errors observed for incongruent items etc., see Table 2S in SM for examples of these other types of measures) is simply not enough. Indeed, because the overall Stroop effect confounds both interference and facilitation, it is impossible to conclude whether a given intervention or practice (e.g., level of physical fitness or measured levels of daily physical activity) is associated with lower interference, greater facilitation, or both.

Experimental studies (i.e., studies in which a given intervention is considered as a potential cause of changes in attentional abilities and is therefore manipulated) face this same issue. Indeed, if effective, any given intervention that aims to improve attention/inhibition should reduce Stroop interference specifically. Again, the distinction between interference and facilitation is important because some interventions (but also a mere repetition of measures in pre- vs. post-intervention designs, see below) might also, or perhaps even exclusively, boost facilitation and/or contingent responding discussed in the previous section (see e.g., Algom et al., 2022; Algom & Chajut, 2019; Schmidt, 2019, 2023 for discussion of these issues in research on processes driving cognitive control).
Additionally, to evidence an attentional boost unambiguously, the aforementioned post-interventional reduction of Stroop interference needs to specifically result from shortened RTs to color-incongruent trials (i.e., increase in speed that is not traded for accuracy, see previous section and see Palfi et al., 2022 for an example of this). Still, because many interventions – including physical activity for instance – simultaneously influence response speed (and not just attentional selectivity), a post-intervention reduction of RTs to color-neutral baseline items will often occur in tandem with a reduction in RTs to incongruent items.

This is a known and long-lasting issue in Stroop research. Because the magnitude of Stroop interference is known to increase proportionally to the slow-down in response speed (see e.g., Martinon et al., 2024; Roelofs, 2010, see also Faust et al., 1999; Spieler et al., 1996), it has been argued that the age-related differences in this magnitude can be entirely explained by the older adults' general slowing and not alterations in their attentional selectivity per se (e.g., Verhaeghen & De Meersman, 1998; see also Verhaeghen, 2000, 2015). This consequently prompted more recent research addressing the effect of healthy and/or pathological ageing on selective attention to better control for concomitant changes in response speed of older adults (e.g., Bugg et al., 2007; Burca et al., 2022). As suggested below, a similar approach is needed to isolate the effect of any given intervention on selective attention/inhibition from its (simultaneous and positive) effect on processing speed.

It is however also important to underline that any experimental intervention that results in performance improvements has to be further isolated from the effects of practice that comes in to play whenever pre- and -post invention measurements of Stroop interference are not sufficiently separated. Therefore, these practice-related changes in response speed also need to be closely monitored when assessing the benefits of a given intervention.
To conclude these opening sections, it seems important recall that the Stroop task is often evoked to illustrate the so-called *task-impurity problem* (MacLeod, 2003; Myiake & Friedman, 2012). This notion refers specifically to the fact that any Stroop performance indicator necessarily includes variance that is attributable to processes other than selective attention and the interference control it entails, like the aforementioned speed of processing (see also e.g., Diamond, 2020; Furley et al., 2023; Smidt et al., 2020 for more general discussions of this issue). Still, the vast majority of methodological and conceptual difficulties discussed above are not related to this task-impurity problem. Rather, these difficulties stem from the design of a given study and/or the type of analyses performed as they consistently fail to isolate interference induced by color-incongruent items (i.e., prime indicator of attentional selectivity and interference control it entails) from other processes observed in the Stroop or other conflict tasks (facilitation, contingent responding etc.). To illustrate this issue, the following section scrutinized these latter aspects in studies assessing the link between physical activity/exercise and attentional abilities.

294

295 **Assessing the link between physical activity and attentional selectivity measured in the**
296 **Stroop task**

297 In line with long-lasting research on processes involved in the Stroop task (e.g.,
298 Chajut & Algom, 2019; MacLeod, 1998; Parris et al., 2022), it was argued above that the
299 most direct measure of *interference* induced by color-incongruent trials is derived by
300 comparing RTs and errors observed with these latter items, against those observed with color-
301 neutral items consisting preferably of non-color words (e.g., *DEAL*<sub>red</sub>). Therefore, the first
302 question that the present section attempts to answer concerns the extent to which this specific
303 comparison is used in research investigating the link (correlational or causal) between *fitness*,
306 To this end, we conducted a bibliographic search on Google Scholar, PsychInfo,
307 Pubmed, Scopus and Web of Science using the following keywords: Stroop task OR Stroop
308 effect OR Stroop interference AND Physical fitness OR physical activity OR physical
309 exercise. This search focused on healthy participants only. The identification, screening, and
310 inclusion/exclusion steps are presented in Figure 1S (see SM). Initially, 55 records of studies
311 – published between 2006-2021 – were identified as carrying out this type of investigation
312 employing the Stroop task (either exclusively or in addition to other cognitive tasks). One
313 record was discarded because, the reported study only used the Stroop task as a stressor. The
314 remaining 54 records – all journal articles – were retrieved and screened. As a results of the
315 first screening for eligibility, three articles were considered as ineligible and therefore
316 excluded (see Figure 1S in SM for further exclusion details).

317 Indicators of Stroop performance used in 51 remaining journal articles were then
318 systematically scrutinized. As a result of this scrutiny, only 9 studies (17,3%) were found to
319 have compared RTs and errors on color-incongruent to some kind of color-neutral baseline
320 (i.e., measured magnitudes of Stroop interference). However, none of them employed non-
321 color words (e.g., *DEAL*<sub>red</sub>) as baseline. 9 other studies (17,3%) measured the magnitude of
322 the overall Stroop effect (i.e., *BLUE*<sub>red</sub> – *BLUE*<sub>blue</sub>, see Table 1S in SM) and the 34<sup>3</sup> (65,4%)
323 remaining studies used other indicators of Stroop performance (e.g., RT and/or errors to
324 color-incongruent trials only – see Table 2S in Supplementary Materials). Although results
325 and conclusions of these latter studies were closely scrutinized (see Tables 1S and 2S in
326 Supplementary Materials for summary), in line with methodological and conceptual

<footnote n="3"><sup>3</sup> One journal article reported two separate experiments; these are presented as two separate entries in Table 2S</footnote>
considerations outlined in the two previous sections, they were no longer considered in what follows (see Figure 1S in SM).

Our next goal was to assess the extent to which physical activity is indeed associated with an increased efficiency and/or a boost in attentional selectivity. Given the paucity of studies measuring Stroop interference (and its reduction) directly (see 9 studies depicted in Table 1), their methodological differences and their remaining shortcomings (see last column of Tables), this issue was assessed via a critical narrative review rather than a systematic review or a metanalysis.

Three out of nine included studies were correlational. Buck et al. (2008) found a positive association between aerobic fitness and percentages of correct responses in each list of the card-/list-version of the Stroop task, however, no association was found between aerobic fitness and the magnitude of Stroop interference (e.g., BLUE<sub>red</sub> - XXXX<sub>red</sub>) in RTs. Despite the absence of this latter (i.e., crucial) association, the study concluded that cognition and notably executive control (interference control) in preadolescent children benefits from fitness. Ishihara et al. (2018) found a negative association between physical fitness and magnitudes of Stroop interference (e.g., BLUE<sub>red</sub> - XXXX<sub>red</sub>) in 9-year-old tennis players showing that the more physically fit children experienced smaller magnitudes of Stroop interference. Although the study concluded that there was a benefit of fitness on inhibitory control, no such association was found when Stroop interference was correlated with daily physical activity or tennis experience. Finally, van der Niet et al. (2015) found a small negative association between time spent in sedentary behavior and magnitudes of Stroop interference. In line with its correlational nature, the study concluded that the more time children spent in sedentary behavior, the worse is their performance.

Six remaining studies were experimental. Two of them suggest a positive effect of acute aerobic and/or resistance exercise on attentional selectivity of middle-aged participants
352 (Alves et al., 2012, 2014). Indeed, in Alves et al. (2014) for instance, the reduced magnitudes
353 of Stroop interference (due to reduced RTs to color-incongruent items only) were observed
354 after a cycling but not stretching (i.e., control) exercise that were administered seven days
355 apart (see Alves et al., 2012 for benefits of 30-min of either walking or strength exercise
356 compared to stretching in middle-aged women).

357 The four remaining experimental studies involved a long-term training intervention
358 (i.e., at least 22-weeks up to 12 months). Indeed, after 22-weeks of a 30-min long physical
359 training program during lunch time (twice a week), primary school children displayed a
360 reduced magnitude of Stroop interference, compared to children that kept the same lunch
361 routine (van der Niet et al., 2016). The authors consequently argued that physical activity
362 benefits executive functioning (notably inhibition) in primary school children. In older
363 women, Best et al. (2014) found a similar benefit after 12 months of 60-min classes (whether
364 these were completed once or twice a week) but also after a balance, toning and relaxation
365 program (i.e., active control program) of the same length. Also, and importantly, a post-
366 intervention reduction in magnitudes of Stroop interference positively predicted adherence to
367 physical activity during the follow-up period (13 to 25 months). While using very similar
368 program in both content and length and administered to a similar population of older women
369 (although possibly significantly older than those recruited in Best et al., 2014), Liu-Ambrose
370 et al. (2010) found no post-intervention reduction of Stroop interference in the active control
371 toning and relaxation program. Sipilä et al. (2021) showed that when coupled with a cognitive
372 training program (i.e., 15-20 minutes computer training of executive functions 3-4 times a
373 week), the selective attention ability of older women benefited from a 12-month physical
374 training program even more than a group of women following a physical training-only
375 program- as evidenced by a greater post-interventional reduction of Stroop interference in the
376 former as compared to a latter group.
To sum up, 8 out of 9 studies reviewed above suggest either an association between the level of exercise/fitness and attentional selectivity (although only in young children) or a positive change in individuals' attentional selectivity following an acute bout of activity, or long-term physical activity (although only in young children or middle-aged or older adults, mostly women, see also Table 1, column entitled "Main findings on Stroop performance only" for further details). Nevertheless, these results need to be interpreted with caution (see also Table 1, column entitled "Main conclusions drawn in the study" for proposed interpretations, and column "Observations and Issues" for elements potentially precluding the proposed interpretation).

As discussed above, none of these studies measured the magnitude of Stroop interference using a non-color word baseline (e.g., *DEAL*<sub>red</sub>). Since almost all of them employed a vocal response modality (see column "Item presentation; Response modality; Number of colors"), the derived magnitude of interference is likely to confound interference on color-incongruent words with faster identification of baseline non-word items (due to the absence of *lexicality cost*, see Figure 1 for a magnitude of this potential confound). This confound might be shown to be problematic when the reduction of interference is scrutinized (i.e., in the case of experimental studies depicted above).

Additionally, not all of these studies effectively controlled for changes in processing speed. This is even more important in studies outlined above, since the effect of physical activity and/or of fitness has been extensively studied in populations presenting high intra- and inter-individual variability in RTs (i.e., children, older adults) that might also evolve rapidly (e.g., between the beginning and the end of 12-months intervention) as function of individual developmental trajectory (Ferrand et al., 2020; Faust et al., 1999).

In light of current research standards, several studies reviewed above might also be underpowered. This is not exclusively due to the high number of observations that
402 correlational studies require or to the high-power requirements for between-groups
403 comparisons that this type of experimental research often entails. Indeed, Brysbaert and
404 Stevens (2018) for instance recommend a minimum of 1,600 observations *per condition* in
405 designs with repeated measures (i.e., all designs including measures of the Stroop effect and
406 of its reduction). Although the number of observations can be divided over participants and
407 items (e.g., 20 participants and 80 observations, 40 participants and 40 observations, or 80
408 participants and 20 observations), some of the studies cited above are far from meeting these
409 standards (see Table 1, column entitled “Stroop task and Item-type (with number of trials if
410 available” and see the same column in Tables 1S & 2S in Supplementary Materials). In line
411 with this reasoning, Ciria et al. (2023) recently concluded that randomized control trials on
412 the effects of physical exercise on cognition indeed suffer from low statistical power.

413 Despite the fact the Stroop task is often considered as “a prototypical inhibition task”
414 (Miyake et al., 2000, p. 57, see above), perhaps the most important challenge that the
415 abovementioned studies face is the interpretation of an increased efficiency and/or a boost in
416 selective attention in terms of underlying processes, namely inhibition and/or the control that
417 attentional selectivity entails (see also Table 1, column entitled “Main conclusions drawn in
418 the study”). Indeed, research from a wide range of conflict tasks suggests that while distractor
419 inhibition certainly contributes to reducing interference from the irrelevant word-dimension
420 (i.e., so-called *inhibition hypothesis*, see Egner & Hirsch, 2005; Wyatt & Machado, 2013),
421 different interventions are also likely to enhance processing of the target (i.e., the ink-color to
422 be identified). In line with this *target amplification hypothesis*, it remains plausible that
423 physical activity actually enhances focus on the relevant color-dimension of the Stroop task
424 (see also e.g., De Jong et al., 1999 for an *increased maintenance of the relevant task-set*).
425 Accordingly, Sibley et al. (2006) reasoned that exercise is likely to improve the maintenance
426 of goal-oriented processing (i.e., it improves a more consistent focus on the color-dimension
instead of on the inhibition of the irrelevant word-dimension, see also Table 2S for details of
this study).

Insert Table 1 near here

Practical guidelines for a more direct measure of selective attention in the Stroop task

In line with conclusions that have been reached by inspecting results from other
inhibitory (e.g., Cremen & Carson, 2017) or executive function tasks (e.g., Furley et al.,
2023), the previous section (along with summaries provided in Tables 1, 1S & 2S) pointed to
the fact that there is a substantial gap between what a given body of research shows and the
conclusions it is able to draw (see namely Tables 1S & 2S in Supplementary Materials for
examples of this gap).

However, this gap is not limited to research on the effects of physical activity nor to
translational (or perhaps more applied) research in general. To illustrate, basic research on
cognitive control (see e.g., Egner, 2023 for a review) for instance, is also prone to some of the
shortcomings outlined above. Indeed, in the Stroop task, a boost in cognitive control is
inferred from the reduction of the overall Stroop effect (and not from the reduction of Stroop
interference, exactly like studies presented in Table 1S) and therefore disregards the role
facilitation plays in this reduction (see e.g., Algom & Chajut, 2019, Algom et al., 2022 for a
discussion of this issue). Additionally, only recently controls for contingency issues –
that the use of color-congruent items induces – have been employed (e.g., Braem et al., 2019,
but see also Schmidt, 2019, 2023). Therefore, this section attempts to provide some up-to-date
practical guidelines designed to eliminate issues that detract from the putative conclusion that
an increased efficiency and/or a boost in selective attention in the Stroop task has indeed been
demonstrated (via any type of laboratory and/or field intervention).
In line with methodological and theoretical arguments outlined above, future correlational and experimental studies need to measure interference on color-incongruent items directly (i.e., against a color-neutral baseline that preferably consists of non-color words, **Issue 1**). If color-congruent items are used as additional (i.e., not a unique) baseline, experimental designs need to control for contingency (**Issue 2**) such that, designs using equal proportions of color-congruent and color-incongruent items should be avoided. Additionally, for experimental studies to evidence the post-interventional boost in attentional selectivity unambiguously, post-interventional reduction of Stroop interference needs to result from shortened RTs to color-incongruent trials (**Issue 3**) – an increase in speed that is clearly not traded for accuracy (as evidenced by simultaneous consideration of both RTs and errors, **Issue 4**). Whenever RTs to a relevant baseline decrease along with those to color-incongruent RTs, it becomes increasingly difficult to assess whether these changes also reflect a boost in selective attention (or in inhibition and/or control it entails) and to what extent (see Palfi et al., 2022 for an example of this). Thus, in order to isolate the effect of physical activity on selective attention per se, future studies need to control for the effect of processing speed (**Issue 5**). This is rather effectively done via proportional transformation (e.g., [(RT<sub>incongruent</sub> - RT<sub>baseline</sub>) / RT<sub>baseline</sub>]. However, it is important to understand that proportional transformation might actually create an advantage for individuals presenting slower RTs (e.g., older adults, children, Hedge et al., 2018). This spurious advantage (compared to populations with faster RTs, e.g., young adult) is no longer present when the variability is instead taken into account using z-scores (Faust et al., 1999; Hedge et al., 2018; see also Burca et al. 2022 for a direct demonstration). To eliminate practice-related changes in response speed (**Issue 6**), pre- and -post-interventional measurements of Stroop interference also need to be sufficiently delayed.

As emphasized in the previous section, a reduced magnitude of Stroop interference does not necessarily result from a reduced interference of the irrelevant word-dimension of
476 incongruent trials (Issue 7). It could alternatively and/or in concert result from an enhanced
477 focus on their relevant color-dimension. To address this issue, several studies on the effects of
478 physical activity used the amount of negative priming (i.e., RTs to trials in which the ink
479 color to be named on N-trial corresponds the (word) stimulus that was ignored on N-1 trial) as
480 an additional indicator of an inhibitory boost (see Table 2S for examples). However, since
481 negative priming is a notoriously controversial measure of selective inhibition (see e.g.,
482 Besner, 2001), a combination of several “inhibitory” tasks<fnref n="4" />, or the use of moderators known
483 to promote target amplification might constitute venues for addressing this latter issue directly
484 (e.g., De Jong et al., 1999, argued that shortening an interval between a response and the
485 presentation of a new stimulus increases a focus on the relevant color-dimension of Stroop
486 stimulus). Nevertheless, post-interventional reductions of Stroop interference can still be
487 interpreted simply in terms of a “boost in attentional selectivity” or a “boost in attentional
488 selectivity and the control it entails” as it is more agnostic with respect to processes actually
489 underlying the reduction (inhibition vs. target amplification / increased goal maintenance
490 etc.).

491 Another important, as yet unaddressed, challenge is to establish whether a
492 demonstrated boost in attentional selectivity is general or limited to a specific subsystem.
493 Indeed, in the Stroop task, distractors can cause conflict at multiple stages within the
494 information-processing system – conflict that may be inhibited by different subsystems
495 (Parris et al., 2022; see also e.g., Berggren & Derakshan, 2014 who showed anxiety affected
496 only one subsystem of attentional control; and Augustinova et al., 2018; Burca et al., 2022
497 and Li & Bosman, 1996 for the same effect of healthy ageing).

<footnote n="4">⁴ Still, many (response) inhibition tasks are prone to the same limitations as those discussed above including the fact that they do not include an appropriate neutral baseline (see e.g., Smith & Ulrich, 2023 for a discussion, see also e.g., Cremen & Carson, 2017 for a discussion of other issues).</footnote>
498

499

500

501

502

503

504

505

506

507

To address this point, future studies might also consider using Stroop tasks that permit the measurement of the independent contributions of *response, semantic and task* conflicts to the Stroop interference effect (see e.g., Hasshim & Parris, 2014 and see Parris et al., 2022 for a review; although see Parris et al., 2023 for a critical discussion of task conflict). Indeed, the ultimate goal of this tutorial section is to help future studies using the Stroop task to make more theoretically and empirically grounded inferences not only about the effects of any given intervention on attentional selectivity (and/or different processes it entails) but also about the levels of processing where these effects take place.

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

Concluding remarks

In times where sedentary lifestyles are increasingly observed in both children and adults (World Health Organization, 2022; Magnon et al., 2018), questioning the positive effect of physical activity and/or of fitness in the Stroop task might seem a bit counterproductive (although see e.g., Ciria et al., 2023). It needs to be remembered at this point that several metanalyses still agree on a positive (although modest) exercise-related benefit on cognition (e.g., Colcombe & Kramer, 2003; Hillman et al., 2008; Barenberg et al., 2011; Guiney, & Machado, 2013; Gomez-Pinilla & Hillman, 2013; Hötting and Röder, 2013; Gajewski & Falkenstein, 2016; Kramer & Colcombe, 2018; Ludyga et al., 2020). Importantly, these metanalyses also included studies of other cognitive functions and/or studies of attention using other tasks (not just the standard color-word Stroop task but also or alternatively a flanker, stop-signal, cuing tasks etc.) – results of which are not considered above (or in Tables 1S and 2S). Although Furley et al. (2023, p.14) convincingly argued “that methodological flaws and measurement problems have been a great issue in the primary studies that have fed into (...)” these meta-analyses and the present paper hopefully illustrated in greater details the type of flaws and measurement problems that occur in the Stroop task specifically, it is still
essential to insist on the importance of physical activity and fitness. In addition to health

benefits (see e.g. Warburton & Bredin, 2017; Melzer et al., 2004), these activities are also

known to enhance psychological and social health outcomes in younger populations (i.e.,

children and adolescents, Eime et al., 2013), and also in older adults (Knight et al., 2022).

Therefore, by no means does the present section of this paper seek to discourage regular

physical activity and/or of high fitness level, or discourage research into their benefits. Rather,

it seeks to draw attention to the uncertainty of the knowledge we currently have on the link

between physical activity and/or exercise on attentional selectivity (see also Furley et al.,

2023 for a similar idea). Indeed, many more carefully designed and powered studies –

conducted in populations covering the entire life-span – are still needed to address the issue of

whether there is a boost in attentional selectivity following physical activity (or any other

intervention) in robust systematic reviews and metanalyses. We only hope that the practical

guidelines outlined above will prove useful in this endeavor.

536

## 537 Declarations

### 538 Funding details

The work reported was supported by RIN Tremplin Grant 19E00851 from Normandie

Region, France and by ANR-19-CE28-0013 Grant from Agence Nationale de la recherche

awarded to all senior authors.

542

### 543 Disclosure statement

The authors report there are no competing interests to declare.

545

## 546 Data availability statement
Data sharing is not applicable to this article as no new data were created or analyzed in this

study

***Supplemental online material***

This paper includes supplementary materials submitted with the main article.

***Authors' contributions***

NR and MA jointly drafted the manuscript. PI, LF, and BP provided substantial intellectual

content. All authors read and approved the final version of the manuscript.

***References***

Algom, D., & Chajut, E. (2019). Reclaiming the Stroop Effect Back From Control to Input-

Driven Attention and Perception. *Frontiers in Psychology, 10*, 1683.

https://doi.org/10.3389/fpsyg.2019.01683

Algom, D., Fitousi, D., & Chajut, E. (2022). Can the Stroop effect serve as the gold standard

of conflict monitoring and control? A conceptual critique. *Memory & Cognition*,

50(5), 883–897. https://doi.org/10.3758/s13421-021-01251-5

Alves, C. R. R., Gualano, B., Takao, P. P., Avakian, P., Fernandes, R. M., Morine, D., &

Takito, M. Y. (2012). Effects of Acute Physical Exercise on Executive Functions: A

Comparison Between Aerobic and Strength Exercise. *Journal of Sport and Exercise*

Psychology, 34(4), 539–549. https://doi.org/10.1123/jsep.34.4.539

Alves, C. R. R., Tessaro, V. H., Teixeira, L. A. C., Murakava, K., Roschel, H., Gualano, B., &

Takito, M. Y. (2014). Influence of Acute High-Intensity Aerobic Interval Exercise

Bout on Selective Attention and Short-Term Memory Tasks. *Perceptual and Motor*

Skills, 118(1), 63–72. https://doi.org/10.2466/22.06.PMS.118k10w4
572

Augustinova, M., Banovic, I., Burca, M., Ferrand, L., Iodice, P., Junker, C., Kernivinen, V.,

573

& Parris, B. A. (2022). Does exposure to pictures of nature boost attentional control in

574

the Stroop task? *Journal of Environmental Psychology*, 84, 101901.

575

https://doi.org/10.1016/j.jenvp.2022.101901

576

Augustinova, M., Clarys, D., Spatola, N., & Ferrand, L. (2018). Some further clarifications on

577

age-related differences in Stroop interference. *Psychonomic Bulletin & Review*, 25,

578

767-774. https://doi.org/10.3758/s13423-017-1427-0

579

Augustinova, M., & Ferrand, L. (2012). Suggestion does not de-automatize word reading:

580

Evidence from the semantically based Stroop task. *Psychonomic Bulletin & Review*,

581

19(3), 521–527. https://doi.org/10.3758/s13423-012-0217-y

582

Augustinova, M., Parris, B. A., & Ferrand, L. (2019). The Loci of Stroop Interference and

583

Facilitation Effects With Manual and Vocal Responses. *Frontiers in Psychology*, 10,

584

1786. https://doi.org/10.3389/fpsyg.2019.01786

585

Augustinova, M., Silvert, L., Spatola, N., & Ferrand, L. (2018). Further investigation of

586

distinct components of Stroop interference and of their reduction by short response-

587

stimulus intervals. *Acta Psychologica*, 189, 54–62.

588

https://doi.org/10.1016/j.actpsy.2017.03.009

589

Barenberg, J., Berse, T., & Dutke, S. (2011). Executive functions in learning processes: Do

590

they benefit from physical activity? *Educational Research Review*, 6(3), 208–222.

591

https://doi.org/10.1016/j.edurev.2011.04.002

592

Bayard, S., Erkes, J., & Moroni, C. (2011). Victoria Stroop Test: normative data in a sample

593

group of older people and the study of their clinical applications in the assessment of

594

inhibition in Alzheimer's disease. *Archives of Clinical Neuropsychology*, 26(7), 653–

595

661. https://doi.org/10.1093/arclin/acr053
Burca, M., Chausse, P., Ferrand, L., Parris, B. A., & Augustinova, M. (2022). Some further clarifications on age-related differences in the Stroop task: New evidence from the two-to-one Stroop paradigm. *Psychonomic Bulletin & Review, 29*(2), 492–500.
https://doi.org/10.3758/s13423-021-02011-x

Ciria, L. F., Román-Caballero, R., Vadillo, M. A., Holgado, D., Luque-Casado, A., Perakakis, P., & Sanabria, D. (2023). An umbrella review of randomized control trials on the effects of physical exercise on cognition. *Nature Human Behaviour, 1*–14.
https://doi.org/10.1038/s41562-023-01554-4

Colcombe, S., & Kramer, A. F. (2003). Fitness Effects on the Cognitive Function of Older Adults: A Meta-Analytic Study. *Psychological Science, 14*(2), 125–130.
https://doi.org/10.1111/1467-9280.t01-1-01430

Cremen, I. A., & Carson, R. G. (2017). Have standard tests of cognitive function been misappropriated in the study of cognitive enhancement?. *Frontiers in human neuroscience, 11*, 276. https://doi.org/10.3389/fnhum.2017.00276

Dalrymple-Alford, E. C. (1972). Associative facilitation and interference in the Stroop color-word task. *Perception & Psychophysics, 11*(4), 274–276.
https://doi.org/10.3758/BF03210377

Dalrymple-Alford, E. C., & Budayr, B. (1966). Examination of Some Aspects of the Stroop Color-Word Test. *Perceptual and Motor Skills, 23*(3_suppl), 1211–1214.
https://doi.org/10.2466/pms.1966.23.3f.1211

De Jong, R., Berendsen, E., & Cools, R. (1999). Goal neglect and inhibitory limitations: Dissociable causes of interference effects in conflict situations. *Acta psychologica, 101*(2-3), 379-394. https://doi.org/10.1016/S0001-6918(99)00012-8

Diamond, A. (2020). Executive functions. In J. L. Michaud, C. Bulteau, D. Cohen, & A. Gallagher (Eds.), *Handbook of clinical neurology* (Vol. 173, pp. 225–240). Elsevier.
670 Gajewski, P. D., & Falkenstein, M. (2016). Physical activity and neurocognitive functioning in aging—A condensed updated review. *European Review of Aging and Physical Activity, 13*(1), 1–7. https://doi.org/10.1186/s11556-016-0161-3

673 Gomez-Pinilla, F., & Hillman, C. (2013). The Influence of Exercise on Cognitive Abilities. *Comprehensive Physiology*, 403–428. https://doi.org/10.1002/cphy.c110063

675 Guiney, H., & Machado, L. (2013). Benefits of regular aerobic exercise for executive functioning in healthy populations. *Psychonomic Bulletin & Review*, 20(1), 73–86.
https://doi.org/10.3758/s13423-012-0345-4

678 Hasshim, N., & Parris, B. A. (2014). Two-to-one color-response mapping and the presence of semantic conflict in the Stroop task. *Frontiers in Psychology, 5*, 1157.
https://doi.org/10.3389/fpsyg.2014.01157

681 Hasshim, N., & Parris, B. A. (2021). The role of contingency and correlation in the Stroop task. *Quarterly Journal of Experimental Psychology, 74*(10), 1657–1668.
https://doi.org/10.1177/17470218211032548

684 Hedge, C., Powell, G., & Sumner, P. (2018). The mapping between transformed reaction time costs and models of processing in aging and cognition. *Psychology and Aging, 33*(7), 1093–1104. https://doi.org/10.1037/pag0000298

687 Heitz, R. P. (2014). The speed-accuracy tradeoff: History, physiology, methodology, and behavior. *Frontiers in Neuroscience, 8*, 150. https://doi.org/10.3389/fnins.2014.00150

689 Hillman, C. H., Erickson, K. I., & Kramer, A. F. (2008). Be smart, exercise your heart: Exercise effects on brain and cognition. *Nature Reviews Neuroscience*, 9(1), 58–65.
https://doi.org/10.1038/nrn2298

692 Hötting, K., & Röder, B. (2013). Beneficial effects of physical exercise on neuroplasticity and cognition. *Neuroscience & Biobehavioral Reviews, 37*(9, Part B), 2243–2257.
https://doi.org/10.1016/j.neubiorev.2013.04.005
695

Ishihara, T., Sugasawa, S., Matsuda, Y., & Mizuno, M. (2018). Relationship between sports

696

experience and executive function in 6-12-year-old children: Independence from

697

physical fitness and moderation by gender. *Developmental Science*, 21(3), e12555.

698

https://doi.org/10.1111/desc.12555

699

Jackson, J. D., & Balota, D. A. (2013). Age-related changes in attentional selection: Quality

700

of task set or degradation of task set across time? *Psychology and Aging*, 28(3), 744–

701

753. https://doi.org/10.1037/a0033159

702

Knight, R. L., Chalabaev, A., McNarry, M. A., Mackintosh, K. A., & Hudson, J. (2022). Do

703

age stereotype-based interventions affect health-related outcomes in older adults? A

704

systematic review and future directions. *British Journal of Health Psychology*, 27(2),

705

338–373. https://doi.org/10.1111/bjhp.12548

706

Kramer, A. F., & Colcombe, S. (2018). Fitness Effects on the Cognitive Function of Older

707

Adults: A Meta-Analytic Study—Revisited. *Perspectives on Psychological Science*,

708

13(2), 213–217. https://doi.org/10.1177/1745691617707316

709

Li, K. Z., & Bosman, E. A. (1996). Age differences in Stroop-like interference as a function

710

of semantic relatedness. *Aging, Neuropsychology, and Cognition*, 3(4), 272-284.

711

https://doi.org/10.1080/13825589608256630

712

Liu-Ambrose, T. (2010). Resistance Training and Executive Functions: A 12-Month

713

Randomized Controlled Trial. *Archives of Internal Medicine*, 170(2), 170–178.

714

https://doi.org/10.1001/archinternmed.2009.494

715

Ludyga, S., Gerber, M., Pühse, U., Looser, V. N., & Kamijo, K. (2020). Systematic review

716

and meta-analysis investigating moderators of long-term effects of exercise on

717

cognition in healthy individuals. *Nature Human Behaviour*, 4(6), 603–612.

718

https://doi.org/10.1038/s41562-020-0851-8
719

MacLeod, C. M. (1991). Half a century of research on the Stroop effect: An integrative

720

review. *Psychological Bulletin*, 109(2), 163–203. https://doi.org/10.1037/0033-

721

2909.109.2.163

722

MacLeod, C. M. (1992). The Stroop task: The “gold standard” of attentional measures.

723

*Journal of Experimental Psychology: General*, 121(1), 12–14.

724

https://doi.org/10.1037/0096-3445.121.1.12

725

MacLeod, C. M., Dodd, M. D., Sheard, E. D., Wilson, D. E., & Bibi, U. (2003). In opposition

726

to inhibition. In B. H. Ross (Ed.), *The psychology of learning and motivation*:

727

*Advances in research and theory* (Vol. 43, pp. 163–214). Elsevier Science.

728

MacLeod, C. M., & MacDonald, P. A. (2000). Interdimensional interference in the Stroop

729

effect: Uncovering the cognitive and neural anatomy of attention. *Trends in cognitive*

730

sciences, 4(10), 383-391. https://doi.org/10.1016/S1364-6613(00)01530-8

731

Magnon, V., Vallet, G. T., & Auxiette, C. (2018). Sedentary Behavior at Work and Cognitive

732

Functioning: A Systematic Review. *Frontiers in Public Health*, 6, 239.

733

https://doi.org/10.3389/fpubh.2018.00239

734

Martinon L.M., Ferrand, L. Burca M, Hasshim N, Lakzoum D, Parris B.A., Silvert L.,

735

Augustinova M. (2024). Distributional Analyses reveal the Polymorphic Nature of the

736

Stroop Interference Effect: It's about (Response) Time. *Memory & Cognition*

737

(accepted)

738

Melzer, K., Kayser, B., & Pichard, C. (2004). Physical activity: the health benefits outweigh

739

the risks. *Current Opinion in Clinical Nutrition & Metabolic Care*, 7(6), 641-647.

740

Miyake, A., & Friedman, N. P. (2012). The nature and organization of individual differences

741

in executive functions: Four general conclusions. *Current Directions in Psychological*

742

*Science*, 21(1), 8–14. https://doi.org/10.1177/0963721411429458
743 Miyake, A., Friedman, N. P., Emerson, M. J., Witzki, A. H., Howerter, A., & Wager, T. D.
744 (2000). The Unity and Diversity of Executive Functions and Their Contributions to
745 Complex “Frontal Lobe” Tasks: A Latent Variable Analysis. *Cognitive Psychology*,
746 41(1), 49–100. https://doi.org/10.1006/cogp.1999.0734

747 Palfi, B., Parris, B. A., Collins, A. F., & Dienes, Z. (2022). Strategies that reduce Stroop
748 interference. *Royal Society Open Science*, 9(3), 202136.
749 https://doi.org/10.1098/rsos.202136

750 Parris, B. A., Hasshim, N., & Dienes, Z. (2021). Look into my eyes: Pupillometry reveals that
751 a post-hypnotic suggestion for word blindness reduces Stroop interference by
752 marshalling greater effortful control. *European Journal of Neuroscience*, 53(8), 2819–
753 2834. https://doi.org/10.1111/ejn.15105

754 Parris, B.A., Hasshim, N., Ferrand, L. & Augustinova, M. (2023). Do Task Sets Compete in
755 the Stroop Task and Other Selective Attention Paradigms? *Journal of Cognition*, 6(1),
756 p.23. https://doi.org/10.5334/joc.272

757 Parris, B. A., Hasshim, N., Wadsley, M., Augustinova, M., & Ferrand, L. (2022). The loci of
758 Stroop effects: A critical review of methods and evidence for levels of processing
759 contributing to color-word Stroop effects and the implications for the loci of
760 attentional selection. *Psychological Research*, 86(4), 1029–1053.
761 https://doi.org/10.1007/s00426-021-01554-x

762 Parris, B. A., Hasshim, N., Augustinova, M., & Ferrand, L. (2022). Do task sets compete in
763 the Stroop task and other selective attention paradigms. *Journal of Cognition*, 6(1), 23.
764 https://doi.org/10.5334/joc.272

765 Parris, B. A., Sharma, D., Weekes, B. S. H., Momenian, M., Augustinova, M., & Ferrand, L.
766 (2019). Response Modality and the Stroop Task: Are There Phonological Stroop
767 Effects With Manual Responses? *Experimental Psychology*, 66(5), 361–367.

768 https://doi.org/10.1027/1618-3169/a000459

769 Quétard, B., Spatola, N., Parris, B. A., Ferrand, L., & Augustinova, M. (2023). A mouse-

770 tracking study of the composite nature of the Stroop effect at the level of response

771 execution. *PLOS ONE*, 18(1), e0279036.

772 https://doi.org/10.1371/journal.pone.0279036

773 Roelofs, A. (2010). Attention and facilitation: converging information versus inadvertent

774 reading in Stroop task performance. *Journal of Experimental Psychology: Learning,*

775 *Memory, and Cognition*, 36(2), 411-422. https://doi.org/10.1037/a0018523

776 Schmidt, J. R. (2013). Questioning conflict adaptation: Proportion congruent and Gratton

777 effects reconsidered. *Psychonomic Bulletin & Review*, 20(4), 615–630.

778 https://doi.org/10.3758/s13423-012-0373-0

779 Schmidt, J. R. (2019). Evidence against conflict monitoring and adaptation: An updated

780 review. *Psychonomic Bulletin & Review*, 26, 753-771.

781 https://link.springer.com/article/10.3758/s13423-018-1520-z

782 Schmidt, J. R. (2023). Is conflict adaptation adaptive? An introduction to conflict monitoring

783 theory and the ecological problems it faces. Quarterly Journal of Experimental

784 Psychology. https://doi.org/10.1177/17470218231161555

785 Sipilä, S., Tirkkonen, A., Savikangas, T., Hänninen, T., Laukkanen, P., Alen, M., Fielding, R.

786 A., Kivipelto, M., Kulmala, J., Rantanen, T., Sihvonen, S. E., Sillanpää, E., Stigsdotter

787 Neely, A., & Törmäkangas, T. (2021). Effects of physical and cognitive training on

788 gait speed and cognition in older adults: A randomized controlled trial. *Scandinavian*

789 *Journal of Medicine & Science in Sports*, 31(7), 1518–1533.

790 https://doi.org/10.1111/sms.13960
791 Smid, C. R., Karbach, J., & Steinbeis, N. (2020). Toward a science of effective cognitive
792 training. *Current Directions in Psychological Science*, 29(6), 531–537.

793 https://doi.org/10.1177/0963721420951599

794 Smith, P., & Ulrich, R. (2023). The neutral condition in conflict tasks: On the violation of the
795 midpoint assumption in reaction time trends. *Quarterly Journal of Experimental

796 Psychology. https://doi.org/10.1177/17470218231201476

797 Spieler, D. H., Balota, D. A., & Faust, M. E. (1996). Stroop Performance in Healthy Younger
798 and Older Adults and in Individuals with Dementia of the Alzheimer's Type. *Journal
799 of Experimental Psychology: Human Perception and Performance*, 22(2), 461–479.

800 Scopus. https://doi.org/10.1037/0096-1523.22.2.461

801 Stroop, J. R. (1935). Studies of interference in serial verbal reactions. *Journal of Experimental
802 Psychology*, 18(6), 643–662. https://doi.org/10.1037/h0054651

803 Troyer, A. K., Leach, L., & Strauss, E. (2006). Aging and response inhibition: Normative data
804 for the Victoria Stroop Test. Aging, *Neuropsychology, and Cognition*, 13(1), 20-35.

805 http://dx.doi.org/10.1080/138255890968187

806 van der Niet, A. G., Smith, J., Oosterlaan, J., Scherder, E. J. A., Hartman, E., & Visscher, C.
807 (2016). Effects of a Cognitively Demanding Aerobic Intervention During Recess on

808 Children's Physical Fitness and Executive Functioning. *Pediatric Exercise Science*,
809 28(1), 64–70. https://doi.org/10.1123/pes.2015-0084

810 van der Niet, A. G., Smith, J., Scherder, E. J. A., Oosterlaan, J., Hartman, E., & Visscher, C.
811 (2015). Associations between daily physical activity and executive functioning in

812 primary school-aged children. *Journal of Science and Medicine in Sport*, 18(6), 673–
813 677. https://doi.org/10.1016/j.jsams.2014.09.006
814

Vandierendonck, A. (2021). On the Utility of Integrated Speed-Accuracy Measures when

815

Speed-Accuracy Trade-off is Present. *Journal of Cognition*, 4(1), 22.

816

https://doi.org/10.5334/joc.154

817

Verhaeghen, P. (2000). The parallels in beauty's brow: Time-accuracy functions and their

818

implications for cognitive aging theories. In T. J. Perfect & E. A. Maylor (Eds.),

819

*Models of cognitive aging* (pp. 50-86). Oxford: Oxford University Press.

820

Verhaeghen, P. (2015). Aging and executive control: Reports of a demise greatly exaggerated.

821

*Current Directions in Psychological Science*, 20, 174-180.

822

https://doi.org/10.1177/0963721411408772

823

Verhaeghen, P., & De Meersman, L. (1998). Aging and the Stroop effect: a meta-analysis.

824

*Psychology and aging*, 13(1), 120-126. https://doi.org/10.1037/0882-7974.13.1.120

825

Warburton, D. E., & Bredin, S. S. (2017). Health benefits of physical activity: a systematic

826

review of current systematic reviews. *Current opinion in cardiology*, 32(5), 541-556.

827

https://doi.org/10.1097/HCO.0000000000000437

828

World Health Organization (2022). Global status report on physical activity 2022. Geneva

829

Wyatt, N., & Machado, L. (2013). Distractor inhibition: Principles of operation during

830

selective attention. *Journal of Experimental Psychology: Human Perception and

831

*Performance*, 39(1), 245-256. https://doi.org/10.1037/a0027922

832
<figure><img src="image_3.png" /><figcaption>Figure 1. Contribution of facilitation, lexicality cost and interference effects to the overall Stroop/congruency effect.</figcaption></figure>

*Note.* Original figure based on data from Augustinova et al. (2019) reported with Verbal (Panel A) and Manual (Panel B) response modality.
Running head: Examining attentional boost in the Stroop task

<table><caption>**Table 1.** Studies measuring the Stroop interference (studies that used color-neutral non-word items as baseline)</caption><thead><tr><th>Authors (year) - Journal</th><th>Sample size (N participants, groups)</th><th>Physical activity/exercise and its control if used</th><th>Item presentation; Response modality; Number of colors</th><th>Stroop task and Item-type (with number of trials if available)</th><th>Indicators of Stroop performance</th><th>Study type with a design</th><th>Main findings on Stroop performance only</th><th>Main conclusions drawn in the study</th><th>Observations and Issues</th></tr></thead><tbody><tr><td>Buck et al. (2008) – Medicine &amp; Science in Sports &amp; Exercise</td><td>74 participants (41 boys, 33 girls; M<sub>age</sub>=9.3)</td><td>Measured level of physical fitness (via aerobic capacity, muscle fitness, body mass index)</td><td>Paper and pencil/list presentation; Vocal; Not mentioned</td><td>3 lists: 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 with color-neutral items (colored Xs)</td><td>% of correct responses (%CR) completed in 45 sec for each list and magnitudes of the Stroop interference (= time difference between color-incongruent and color-neutral (non-word) condition)</td><td>Correlational using aerobic fitness as predictor of (single measure of) Stroop performance</td><td>Positive association between aerobic fitness and %CR in each list, but no such association with the Stroop interference</td><td>Benefit of fitness for cognition and notably executive control (interference control) in preadolescent children</td><td>Magnitude of Stroop interference inflated by the use of a non-word baseline, creating a lexicality cost confound (Issue 1)<br/>No direct indicator of inhibition (Issue 7)</td></tr><tr><td>Ishihara et al. (2018) – Developmental Science</td><td>68 participants, all tennis players (M<sub>age</sub>=9.6)</td><td>Measured level of physical fitness (via accelerometry)</td><td>Computerized item-by-item presentation; Manual (keys on a computer keyboard); 4 (red, yellow, blue, and green)</td><td>2 blocks each consisting of 64 trials: 1 block with color-neutral items (colored patches) and 1 block with color-words items printed in incongruent colors (1-min rest between the two blocks, 128 trials in total)</td><td>%ER, mean RTs and magnitudes of the Stroop interference (= time difference between color-incongruent and color-neutral (patch) condition)</td><td>Correlational using physical fitness as predictor of (single measure of) Stroop performance</td><td>Negative association between physical fitness and magnitudes of interference that is specifically due to reduction of RTs to incongruent items only</td><td>Benefit of fitness (but not of daily physical activity or tennis experience) on inhibitory control</td><td>Magnitude of Stroop interference inflated by the use of a non-word baseline, creating a lexicality cost confound (Issue 1)<br/>No direct indicator of inhibitory control (Issue 7)</td></tr><tr><td>van der Niet et al. (2015) – Journal of Science and Medicine in Sport</td><td>80 participants (8-12 years old)</td><td>Measured level of physical fitness and time spent in sedentary behavior (via accelerometry)</td><td>Paper and pencil/list presentation; Vocal; Not mentioned</td><td>3 lists: 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 with color-neutral items (colored rectangles)</td><td>Number of CR completed in 45 sec for each list (not reported) and the magnitudes of the Stroop interference (= CR in the color-incongruent condition / CR in the color-neutral condition =&gt; higher</td><td>Correlational using physical fitness and time spent in sedentary behavior as predictors of (single measure of) Stroop performance</td><td>Small negative association between time spent in sedentary behavior and interference ratios</td><td>The more time children spent in sedentary behavior, the worse is their performance on this inhibition task</td><td>Magnitude of Stroop interference inflated by the use of a non-word baseline, creating a lexicality cost confound (Issue 1)<br/>Additional control for response speed via interference ratio</td></tr></tbody></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Alves et al. (2014) – Perceptual &amp; Motor Skills: Learning &amp; Memory</td><td>22 participants (M<sub>age</sub>=53.7)</td><td>10x1-min cycling bouts interspersed by 1 min. active (<b>acute aerobic exercise</b>) vs 10 min instruction about the benefits of regular exercise followed by 15 min of stretching (<b>active control activity</b>)</td><td>Paper and pencil/list presentation (Stroop Victoria); Vocal; 3</td><td>3 color-naming lists each consisting of 24 colored items: 1 with color-neutral items (colored dots), 1 with color-neutral words items, and 1 with color-words items printed in incongruent colors</td><td>% of correct responses (%CR) and completion times (in sec) in each list and magnitudes of the <b>Stroop interference</b> (= time difference between color-incongruent and color-neutral dot (non-word) condition)</td><td>Experimental comparing Stroop performance collected after acute aerobic exercise AND after control activity (administered in counter-balanced order 7 days apart)</td><td>Reduced magnitudes of the <b>Stroop interference</b> after exercise (but not after control) activity due to reduced RTs to color-incongruent items only</td><td>Results suggest that acute aerobic exercise improves selective attention and susceptibility to interference from conflicting stimuli</td><td>Conclusion about inhibition not supported by the results (<b>Issue 7</b>)<br>Low N participants<br>Magnitude of Stroop interference inflated by the use of a non-word baseline, creating a lexicality cost confound (<b>Issue 1</b>)<br>Possible practice effect (<b>Issue 6</b>)</td></tr><tr><td>Alves et al. (2012) – Journal of Sport and Exercise Psychology</td><td>42 female participants (M<sub>age</sub>=52)</td><td>30 min walking (<b>acute aerobic exercise</b>) vs 2 sets of 15 repetitions for 6 exercises of the lower and upper limbs (<b>acute resistance exercise</b>) vs 10-min instruction about the benefits of regular exercise followed by a 15 min of stretching (<b>active control activity</b>)</td><td>Paper and pencil/list presentation (Stroop Victoria); Vocal; 4</td><td>3 color-naming lists each consisting of 24 colored items: 1 with color-neutral items (colored dots), 1 with color-neutral words items, and 1 with color-words items printed in incongruent colors</td><td>% of correct responses (%CR) and completion times (in sec) in each list and magnitudes of two ratios: <b>color-neutral words/dot</b> and <b>incongruent word/color-neutral word</b></td><td>Experimental comparing Stroop performance collected after aerobic exercise AND strength exercise AND control activity (administered in counter-balanced order 7 days apart)</td><td>Reduced completion times to color-neutral and incongruent items and reduced interference ratios after both aerobic and strength exercise (but not after control) activity</td><td>Both types of exercises improve selective attention and susceptibility to interference from conflicting stimuli.<br>Both types of exercises are beneficial for executive functioning</td><td>Magnitude of Stroop interference inflated by the use of a non-word baseline, creating a lexicality cost confound (<b>Issue 1</b>)<br>Computation of ratios to account for change in response speed<br>Possible practice effect (<b>Issue 6</b>)</td></tr><tr><td>van der Niet et al. (2016) – Pediatric Exercise Science</td><td>105 participants (8-12 years old): assigned to physical training (PT, N=53) vs. control group (N=52)</td><td>22-weeks <b>physical training program</b> during lunch time (30-min sessions, twice a week) in the <b>PT group</b> vs. the same lunch routine (<b>passive control group</b>)</td><td>Paper and pencil/list presentation; Vocal; Not mentioned</td><td>3 lists (no information about the contingencies): 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 with color-neutral items</td><td>Number of CR completed in 45 sec for each list (not reported) and <b>interference ratio</b> (= CR in the color-incongruent condition / CR in the color-neutral condition => higher ratio=better performance)</td><td>Experimental* analyzing pre- vs. post-intervention Stroop performance (collected 22 weeks apart) as a function of PT vs. <b>control group</b> (*children group assignment based on parental consent)</td><td>Post-intervention reduction of interference ratio in the PT (vs. control group)</td><td>Benefit of physical activity program on executive functioning (notably <b>inhibition</b>) in primary school children</td><td>Magnitude of Stroop interference inflated by the use of a non-word baseline, creating a lexicality cost confound (<b>Issue 1</b>)<br>Additional control for response speed via interference ratios</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><thead><tr><th></th><th></th><th></th><th></th><th>(colored rectangles)</th><th></th><th></th><th></th><th></th><th></th><th>No direct indicator of inhibition (Issue 7)</th></tr></thead><tbody><tr><td>Best et al. (2014) – Frontiers in Human Neurosciences</td><td>125 female participants (M<sub>age</sub>=69.5) assigned to Once-(N=44) vs. Twice-weekly training group (N=45) vs. Control group (N=36)</td><td>12-month high-intensity resistance training program (60-min classes) once vs twice a week vs balance, toning and relaxation program (active control group)</td><td>Paper and pencil/list presentation; Vocal; Not mentioned</td><td>3 lists each consisting of 80 items: 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 with color-neutral items (colored Xs)</td><td>Completion times (in sec) in each list and magnitudes of the Stroop interference (= time difference between color-incongruent and color-neutral (non-word) condition). And a Δ between Stroop interference at month 12 and month 0</td><td>Experimental analyzing pre- and post-intervention Stroop performance (collected 12 months apart) as a function of once vs. twice a week exercise group vs active control</td><td>Reduced magnitudes the Stroop interference after intervention as compared to before in all groups (including control) positively related to adherence to physical activity during the follow-up period (months 13 to 25)</td><td>Improving executive functions (in particular, inhibition of prepotent responses) plays an important role in whether older women maintain higher levels of physical activity following exercise training</td><td>Magnitude of Stroop interference inflated by the use of a non-word baseline, creating a lexicality cost confound (Issue 1)<br/>No results about changes in the incongruent condition (possibly Issue 3)<br/>No measure/analysis of errors (possibly Issue 4)<br/>Lack of control for changes in response speed (possibly Issue 5)<br/>No direct indicator of inhibition (Issue 7)</td></tr><tr><td>Liu-Ambrose et al. (2010) – Archives of Internal Medicine</td><td>135 female participants (M<sub>age</sub>=82.2) assigned to Once-(N=47) vs. Twice-weekly training group (N=46) vs. Control group (N=42)</td><td>12-month high-intensity resistance training (60-min classes) once vs twice a week vs balance, toning and relaxation program (active control group)</td><td>Paper and pencil/list presentation; Vocal; Not mentioned</td><td>3 lists each consisting of 80 items: 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 with color-neutral items (colored Xs)</td><td>Completion times (in sec) in each list (not reported in the MS) and magnitudes of the Stroop interference (= time difference between color-incongruent and color-neutral (non-word) condition)</td><td>Experimental analyzing pre- vs. midterm vs. post-intervention Stroop performance (collected 6 months apart) as a function of once vs. twice a week exercise group vs active control</td><td>Reduced magnitudes the Stroop interference after intervention as compared to before following both the once- and twice-weekly training program (but not after control activity)</td><td>Benefit of resistance training on executive functioning of selective attention and conflict resolution in senior women</td><td>Magnitude of Stroop interference inflated by the use of a non-word baseline, creating a lexicality cost confound (Issue 1)<br/>No results about changes in the incongruent condition (possibly Issue 3)<br/>No measure/analysis of errors (possibly Issue 4)</td></tr></tbody></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Sipilä et al. (2021) – Scandinavian Journal of Medicine and Science in Sports</td><td>314 participants (M<sub>age</sub>=74.5) assigned to Physical and Cognitive training group (PTCT, N=155) vs Physical training (PT, N=159) group</td><td>12-month PT (aerobic, balance, resistance exercise, 2-3 sessions/week) vs 12-month PTCT (PT with additional computer training of executive functions (3-4 sessions/week); no active or passive control group</td><td>Paper and pencil/list presentation; Vocal; Not mentioned</td><td>3 lists each consisting of 72 items: 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 with color-neutral items (colored Xs) (referred to as congruent)</td><td>Completion times (in sec) in each list (not reported in the MS) and magnitudes of the Stroop interference (= time difference between color-incongruent and color-neutral (non-word) condition)</td><td>Experimental analyzing pre- vs. midterm vs. post-intervention Stroop performance (collected 6 months apart) as a function of training type (physical + cognitive vs. physical training only)</td><td>Post-intervention reduction of interference in both training groups but greater in the PTCT than the PT group</td><td>Greater benefit of combined physical and cognitive training on response inhibition than that of physical training alone</td><td>No direct indicator of inhibition (Issue 7)<br>Magnitude of Stroop interference inflated by the use of a non-word baseline, creating a lexicality cost confound (Issue 1)<br>No results about changes in the incongruent condition (possibly Issue 3)<br>No measure/analysis of errors (possibly Issue 4)<br>Lack of control for changes in response speed (possibly Issue 5)<br>No direct indicator of inhibition (Issue 7)</td></tr></table>

Note. Light gray background indicates an “overinterpretation” of reported results and dark gray indicates a clear mismatch between empirical results and their interpretation.
# Supplementary Materials

## Table of contents

<table><tr><td>Figure 1S</td><td>2</td></tr><tr><td>Table 1S</td><td>3</td></tr><tr><td>References (Table 1S)</td><td>10</td></tr><tr><td>Table 2S</td><td>12</td></tr><tr><td>References (Table 2S)</td><td>29</td></tr></table>
<figure><img src="image_4.png" /></figure>

**Figure 1S.** Flowchart (adapted from Page et al., 2021) depicting the selection process of the included studies. The results of the included studies are discussed in the main text of the manuscript, while the results of excluded studies are displayed in the supplementary tables 1S and 2S in the Supplementary Materials.

**References (Figure 1S)**

Page, M. J., McKenzie, J. E., Bossuyt, P. M., Boutron, I., Hoffmann, T. C., Mulrow, C. D., ... & Moher, D. (2021). The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. *BMJ, 372*.
Running head: Examining attentional boost in the Stroop task

<table><caption>**Table 1S.** Studies measuring the overall Stroop effect (studies that used congruent baseline items as baseline)</caption><thead><tr><th>Authors (year) - Journal</th><th>Sample size (N participants, groups)</th><th>Physical activity/exercise and its control if used</th><th>Item presentation; Response modality; Number of colors</th><th>Stroop task and Item-type (with number of trials if available)</th><th>Indicators of Stroop performance</th><th>Study type with a design</th><th>Main findings on Stroop performance only</th><th>Main conclusions drawn in the study</th><th>Observations and issues</th></tr></thead><tbody><tr><td>Bento-Torres et al. (2019) – Journal of Sport and Health Science</td><td>48 participants (M<sub>age</sub>=24.6)</td><td>Measured level of cardiorespiratory fitness (CRF) (via a field test) and physical activity (via accelerometry)</td><td>Computerized item-by-item presentation; Manual (Pressing a key on a standard keyboard with the index, middle, and ring fingers of the right hand); Not mentioned</td><td>A single block consisting of 54 color-words items printed in congruent color, 48 words items printed in incongruent color, and 63 color-neutral words items printed in color, presented randomly (165 trials in total)</td><td>%ER, RTs (in ms), SD (indicator of inter-individual variability, IIV) and the Stroop effect ratio (= (RTs to color-incongruent trials - color-congruent trials) / RTs to color-congruent trials))</td><td>Correlational using physical fitness and CRF as predictors of (single measure of) Stroop performance</td><td>No association between physical activity and IIV for either Stroop condition and Stroop effect ratios<br>No other associations with Stroop performance are reported</td><td>No conclusions with respect to Stroop performance</td><td>Magnitude of Stroop interference inflated by the use of a color-congruent baseline (despite the use of a color-neutral words condition), creating a facilitation confound (Issue 1)<br>No control of the color-congruent items contingency (Issue 2)<br>Computation of ratios to account for change in response speed</td></tr><tr><td>Li et al. (2021) – Brain Sciences</td><td>180 participants (M<sub>age</sub>=20.2)</td><td>Measured level of physical activity (PA) (via the International Physical Activity Questionnaire, IPAQ)</td><td>Computerized item-by-item presentation; Manual (color-coded keys on a computer keyboard); 4 (blue, green, red, and green)</td><td>2 blocks each consisting of 8 color-words items printed in congruent color and 24 color-words items printed in incongruent color, presented randomly (64 trials in total)</td><td>%ER, RTs (in ms), and magnitudes of the Stroop effect (= RTs to color-incongruent trials - color-congruent trials)</td><td>Correlational using physical activity as predictor of (single measure of) Stroop performance</td><td>Negative association between physical activity and the magnitude of the Stroop effect.<br>No significant association between physical activity level and RTs to congruent and</td><td>A higher level of physical activity is linked to better inhibitory control in young adults</td><td>Magnitude of Stroop interference inflated by the use of a color-congruent baseline, creating a facilitation confound (Issue 1)<br>No specific correlation with RTs on</td></tr></tbody></table>
Running head: Examining attentional boost in the Stroop task

<table><thead><tr><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th></tr></thead><tbody><tr><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Peven et al. (2018) – Journal of Cognitive Enhancement</td><td>96 participants (M<sub>age</sub>=65.8)</td><td>Measured level of physical activity (PA, via accelerometry) resulting in the identification of two categories of activity bouts duration (&lt; 10 or ≥ 10 min)</td><td>Computerized item-by-item presentation; not mentioned; not mentioned</td><td>54 color-words items printed in congruent color, 63 color-neutral words items printed in color and 48 color-words items printed in incongruent color, presented randomly (165 trials in total, no information about the number of block and item randomization)</td><td>%ER (reported, but integrated into the statistical analyses), RTs (in ms) and magnitudes the Stroop effect (= RTs to color-incongruent trials - color-congruent trials)</td><td>Correlational using physical activity and number of &lt; 10 or ≥ 10 min bouts of activity as predictors of (single measure of) Stroop performance</td><td>Hierarchical linear regression models revealed that higher levels of PA and more bouts of ≥ 10 min were associated with smaller magnitude of the Stroop effect and lower RTs to incongruent items</td><td>Physical activity level is associated with better executive function (inhibitory function)</td><td>incongruent items (Issue 3)<br/>No direct indicator of inhibitory control (Issue 7)<br/>Magnitude of Stroop interference inflated by the use of a color-congruent baseline (despite the use of a color-neutral words condition), creating a facilitation confound (Issue 1)<br/>No control of the color-congruent items contingency (Issue 2)<br/>No analysis of errors (possibly Issue 4)<br/>No direct indicator of inhibitory control (Issue 7)</td></tr><tr><td>Stillman et al. (2016) – PloS ONE</td><td>41 participants (M<sub>age</sub>=23.9)</td><td>Measured level of cardiorespiratory fitness (CRF) (via exercise test) and of physical activity (PA) (via accelerometry)</td><td>Computerized item-by-item; Manual (response glove); Not mentioned</td><td>A single block consisting of 40 color-words items printed in congruent color, 40 color-neutral words items printed in color and 40 color-words items printed in incongruent color, presented</td><td>%ER, RTs (in ms, not reported in the results), no errors (due to “high accuracy”) and magnitudes of and Stroop effect ratios (= RTs to color-incongruent trials - color-congruent trials)</td><td>Correlational using PA as predictor of (single measure of) Stroop performance (no analyses of CRF reported)</td><td>Negative association between physical activity and the magnitude of the Stroop effect ratio. No analyses of RTs and %ER</td><td>Higher physical activity levels are associated with better executive functioning</td><td>Magnitude of Stroop interference inflated by the use of a color-congruent baseline (despite the use of a color-neutral words condition), creating a</td></tr></tbody></table>
Running head: Examining attentional boost in the Stroop task

<table><thead><tr><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th></tr></thead><tbody><tr><td></td><td></td><td></td><td>randomly (120 trials in total)</td><td>/ RTs to color-congruent trials)</td><td></td><td></td><td>facilitation confound (Issue 1)</td><td></td></tr><tr><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>No control of the color-congruent items contingency (Issue 2)</td><td></td></tr><tr><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>No results about changes in the incongruent condition (possibly Issue 3)</td><td></td></tr><tr><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>Computation of ratios to account for change in response speed</td><td></td></tr><tr><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>No direct indicator of inhibition (Issue 7)</td><td></td></tr><tr><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>Low N participants for a correlational study</td><td></td></tr><tr><td>Peven et al. (2019) – Brain Plasticity</td><td>50 participants (M<sub>age</sub>=25.2)</td><td>Measured level of cardiorespiratory fitness (CRF) via exercise test) resulting in the comparison of higher vs lower CRF group</td><td>Computerized item-by-item; Manual (response glove); Not mentioned</td><td>54 color-words items printed in congruent color, 63 color-neutral words items printed in color and 48 color-words items printed in incongruent color, presented randomly (165 trials in total, no information about the number of block and item randomization)</td><td>RTs (in ms), no errors (due to “high accuracy”) and magnitudes of and Stroop effect ratios (= (RTs to color-incongruent trials - color-congruent trials) / RTs to color-congruent trials)</td><td>Experimental* comparing (single measure of) Stroop performance as a function of higher or lower CRF group *determination of groups based on the measured levels of cardiorespiratory fitness</td><td>Negative association between CRF and RTs to color-incongruent and -neutral conditions as compared to lower CRF. No such effect found on color-congruent items and Stroop effect ratio</td><td>Cardiorespiratory fitness is associated with enhanced executive functions and notably selective attention</td><td>Magnitude of Stroop interference inflated by the use of a color-congruent baseline (despite the use of a color-neutral words condition), creating a facilitation confound (Issue 1)</td><td>No control of the color-congruent</td></tr></tbody></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Brush et al. (2016) – Journal of Sport and Exercise Psychology</td><td>28 participants (M<sub>age</sub>=20.5)</td><td>Acute resistance exercise of low (40% 10-RM), moderate (70% 10-RM), high intensity (100% 10-RM) vs watching a 45-min instructional video on how to perform various resistance exercises)</td><td>Computerized item-by-item presentation; Not mentioned; Not mentioned</td><td>2 color-naming blocks each consisting of 36 color-words items printed in congruent color, and 36 color-words items printed in incongruent color, presented randomly (144 trials in total)</td><td>%ER, RTs (in ms), and magnitude of the Stroop effect (= RTs/%ER to color-incongruent trials - color-congruent trials)</td><td>Experimental comparing Stroop performance collected 15 and 180mn after acute resistance exercise AND after control activity (administered in counter-balanced order at least 48h apart)</td><td>At 15 min postexercise: Post-intervention reduction of the Stroop effect increased linearly as a function training intensity (but the effect is not driven by the change in RTs to incongruent trials)<br/>No effect at 180 min postexercise</td><td>Limited and task-specific influence of acute resistance exercise on executive function, especially inhibition in healthy young adults</td><td>items contingency (Issue 2)<br/>Computation of ratios to account for change in response speed<br/>No direct indicator of inhibition (Issue 7)<br/>Low N participants<br/>Magnitude of Stroop interference inflated by the use of a color-congruent baseline, creating a facilitation confound (Issue 1)<br/>No control of the color-congruent items contingency (Issue 2)<br/>No specific correlation with RTs on incongruent items (Issue 3)<br/>Possible practice issue (Issue 6)<br/>No direct indicator of inhibition (Issue 7)</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Journal of Clinical Medicine</td><td>N=24) and older (M<sub>age</sub>=70, N=20) adults, all assigned to both aerobic exercise and control activity</td><td>exercise at 60-70% of HRR (<b>Acute aerobic exercise</b>) vs 20-min of sitting quietly and watch a video related to sport science (<b>passive control activity</b>)</td><td>presentation; Manual (color-coded keys on a computer keyboard); 3 (red, blue, green)</td><td>color-words items printed in congruent color and 18 color-words items printed in incongruent color (360 trials in total)</td><td>magnitudes of the <b>Stroop effect</b> (= RTs/%ER to color-incongruent trials - color-congruent trials)</td><td>post-intervention Stroop performance collected for both <b>acute exercise</b> and <b>control</b> conditions (counterbalanced and administered at least 96h apart)<br/>*Comparison of 2 age groups</td><td><b>reduction of the Stroop effect</b> in the exercise compared to control condition (however due to shorter RTs to incongruent trials)</td><td>beneficial to <b>inhibition</b> in young and older adults</td><td>interference inflated by the use of a color-congruent baseline, creating a facilitation confound (<b>Issue 1</b>)<br/>No control for the color-congruent items contingency, leading to a facilitation issue due to contingent responding (<b>Issue 2</b>)<br/>Lack of control for changes in response speed (possibly <b>Issue 5</b>)<br/>Possible practice effect (<b>Issue 6</b>) although differences in interventions suggest more than that<br/>No direct indicator of inhibition (<b>Issue 7</b>)<br/>Low N participants in both age groups</td></tr><tr><td>Konijnenberg and Fredriksen (2018) – Scandinavian Journal of Public Health</td><td>1173 participants (AGE=7-12) assigned to physical training (PT, N=793) vs. control group. Only the 9-12 years olds</td><td>12-month <b>physical training program</b> (45 min of moderate to high (25-30% of the time) intensity physical activity a day) vs. keeping the same routine</td><td>Computerized item-by-item presentation; Manual (color-coded keys on a computer keyboard); 4</td><td>A single block consisting of 84 trials including color-words items printed in congruent color, color-words items printed in</td><td>%ER, RTs (in ms), and magnitudes of the <b>Stroop effect</b> (= RTs/%ER to color-incongruent trials - color-congruent trials - color-congruent trials)</td><td><b>Experimental</b> analyzing pre- vs. post-intervention Stroop performance as function of <b>physical training</b> vs. <b>control</b></td><td>Post-intervention <b>reduction of the Stroop effect</b> in both the exercise and control groups (due to the overall)</td><td>The physical activity intervention program had no positive effect on <b>children's executive control</b></td><td>Magnitude of Stroop interference inflated by the use of a color-congruent baseline, creating a facilitation</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>performed the Stroop task, the 7-8 years olds performed the Flanker task (no information about the contingencies in these age groups)</td><td>(pseudo-passive control)</td><td>(blue, green, red, and black)</td><td>incongruent color and color-neutral items (colored squares) (contingencies not mentioned), presented randomly</td><td>trials – color-congruent trials)</td><td>reduction of RTs to all items)</td><td>confound (Issue 1)<br/>Possible contingency issue (Issue 2)<br/>Improvement consistent with a normal developmental trajectory; Lack of control for changes in response speed (possibly Issue 5)<br/>No direct indicator of inhibition (Issue 7)</td></tr></table>

Note. Light gray background indicates an “overinterpretation” of reported results and dark grey indicates a clear mismatch between empirical results and their interpretation.
References (Table 1S)

Bento-Torres, J., Bento-Torres, N. V. O., Stillman, C. M., Grove, G. A., Huang, H., Uyar, F., Watt, J. C., Wollam, M. E., & Erickson, K. I. (2019). Associations between cardiorespiratory fitness, physical activity, intraindividual variability in behavior, and cingulate cortex in younger adults. *Journal of Sport and Health Science, 8*(4), 315-324. https://doi.org/10.1016/j.jshs.2019.03.004

Brush, C. J., Olson, R. L., Ehmann, P. J., Osovsky, S., & Alderman, B. L. (2016). Dose-Response and Time Course Effects of Acute Resistance Exercise on Executive Function. *Journal of Sport and Exercise Psychology, 38*(4), 396-408.
https://doi.org/10.1123/jsep.2016-0027

Dimitrova, J., Hogan, M., Khader, P., O'Hora, D., Kilmartin, L., Walsh, J. C., Roche, R., & Anderson-Hanley, C. (2017). Comparing the effects of an acute bout of physical exercise with an acute bout of interactive mental and physical exercise on electrophysiology and executive functioning in younger and older adults. *Aging Clinical and Experimental Research, 29*(5), 959-967. https://doi.org/10.1007/s40520-016-0683-6

Hsieh, S.-S., Huang, C.-J., Wu, C.-T., Chang, Y.-K., & Hung, T.-M. (2018). Acute Exercise Facilitates the N450 Inhibition Marker and P3 Attention Marker during Stroop Test in Young and Older Adults. *Journal of Clinical Medicine, 7*(11), 391.
https://doi.org/10.3390/jcm7110391

Konijnenberg, C., & Fredriksen, P. M. (2018). The effects of a school-based physical activity intervention programme on children's executive control: The Health Oriented Pedagogical Project (HOPP). *Scandinavian Journal of Public Health, 46*(21_suppl), 82-91. https://doi.org/10.1177/1403494818767823
Running head: Examining attentional boost in the Stroop task

Li, L., Yu, Q., Zhao, W., Herold, F., Cheval, B., Kong, Z., Li, J., Mueller, N., Kramer, A. F., Cui, J., Pan, H., Zhan, Z., Hui, M., & Zou, L. (2021). Physical Activity and Inhibitory Control: The Mediating Role of Sleep Quality and Sleep Efficiency. *Brain Sciences, 11*(5), Article 5. https://doi.org/10.3390/brainsci11050664

Peven, J. C., Grove, G. A., Jakicic, J. M., Alessi, M. G., & Erickson, K. I. (2018). Associations Between Short and Long Bouts of Physical Activity with Executive Function in Older Adults. *Journal of Cognitive Enhancement, 2*(2), 137-145.
https://doi.org/10.1007/s41465-018-0080-5

Peven, J. C., Litz, G. A., Brown, B., Xie, X., Grove, G. A., Watt, J. C., & Erickson, K. I. (2019). Higher Cardiorespiratory Fitness is Associated with Reduced Functional Brain Connectivity During Performance of the Stroop Task. *Brain Plasticity, 5*(1), 57-67.
https://doi.org/10.3233/BPL-190085

Stillman, C. M., Watt, J. C., Grove, G. A., Wollam, M. E., Uyar, F., Mataro, M., Cohen, N. J., Howard, D. V., Howard, J. H., & Erickson, K. I. (2016). Physical Activity Is Associated with Reduced Implicit Learning but Enhanced Relational Memory and Executive Functioning in Young Adults. *PLOS ONE, 11*(9), e0162100.
https://doi.org/10.1371/journal.pone.0162100
Running head: Examining attentional boost in the Stroop task

<table><caption>**Table 2S.** Studies using other (perhaps less conclusive) performance indicators of attentional selectivity</caption><thead><tr><th>Authors, year -<br>Journal</th><th>Sample size<br>(N<br>participants,<br>groups)</th><th>Physical<br>activity/exercise and<br>its control if used</th><th>Item<br>presentation;<br>Response<br>modality;<br>Number of<br>colors</th><th>Stroop task and<br>Item-type (with<br>number of trials if<br>available)</th><th>Indicators of<br>Stroop<br>performance</th><th>Study type with<br>a design</th><th>Main findings on<br>Stroop<br>performance only</th><th>Main conclusions<br>drawn in the study</th><th>Observations<br>and Issues</th></tr></thead><tbody><tr><td>Aadland et al.<br>(2014) – Mental<br>Health and<br>Physical Activity</td><td>697<br>participants<br>(357 girls and<br>340 boys,<br>M<sub>age</sub>=10.2)</td><td>Measured level of<br>physical activity,<br>sedentary time,<br>aerobic fitness and<br>motor skills</td><td>Paper and<br>pencil/list<br>presentation;<br>Vocal; 3 (red,<br>blue, green)</td><td>3 lists:<br>1 word-reading list<br>with color-words<br>items printed in<br>black; 2 color-<br>naming lists: 1 with<br>color-words items<br>printed in<br>incongruent colors<br>and 1 with color-<br>neutral items<br>(colored Xs)</td><td>Number of<br>correct<br>responses in 45<br>seconds in the<br>incongruent<br>color-naming<br>list only (no<br>use of baseline)</td><td>Correlational<br>using physical<br>activity<br>sedentary time,<br>aerobic fitness<br>and motor skills<br>levels as<br>predictors of<br>(single measure<br>of) Stroop<br>performance</td><td>No association<br>between physical<br>activity and Stroop<br>performance,<br>Positive<br>associations<br>between motor<br>skills sedentary,<br>time, aerobic fitness<br>and Stroop<br>performance</td><td>Physical activity (as<br>opposed to motor<br>skills) is not a way to<br>improve executive<br>functions, especially<br>inhibition</td><td>No<br>comparison to<br>a non-color<br>words neutral<br>baseline (Issue<br>1)<br><br>No direct<br>indicator of<br>inhibition<br>(Issue 7)</td></tr><tr><td>Bixby et al.<br>(2007) –<br>Medicine &<br>Science in Sports<br>& Exercise</td><td>120<br>participants<br>(M<sub>age</sub>=78.9)</td><td>Measured level of<br>physical activity (via<br>the Yale Physical<br>Activity Survey,<br>YPAS)</td><td>Not<br>mentioned;<br>Vocal; 3 (red,<br>green, blue)</td><td>3 lists:<br>1 word-reading list<br>with color-words<br>items printed in<br>black; 2 color-<br>naming lists: 1 with<br>color-words items<br>printed in<br>incongruent colors<br>and 1 with color-<br>neutral items<br>(colored Xs)</td><td>Number of<br>correct<br>responses in 45<br>seconds for<br>each condition;<br>Calculation of a<br>"predicted<br>color-word<br>score":<br>word<br>reading score<br>score*neutral<br>score / word<br>reading score +<br>neutral score;<br>Calculation of<br>an<br>"interference<br>score":<br>Incongruent<br>score –<br>predicted color<br>score (A higher<br>score reflecting<br>more resistance<br>to interference)</td><td>Correlational<br>using physical<br>activity as<br>predictor of<br>(single measure<br>of) Stroop<br>performance</td><td>Positive association<br>between physical<br>activity and<br>performance in the<br>incongruent items<br>and the<br>"interference<br>score"<br><br>No association<br>between physical<br>activity and<br>performance in the<br>word-reading and<br>neutral items</td><td>Higher physical<br>activity levels are<br>beneficial to inhibitory<br>executive function in<br>older adults</td><td>Word-reading<br>condition as<br>baseline; No<br>comparison to<br>a non-color<br>words neutral<br>baseline (Issue<br>1)<br><br>No direct<br>indicator of<br>inhibition<br>(Issue 7)</td></tr><tr><td>Prakash et al.<br>(2011) – Frontiers<br>in Psychology</td><td>70 participants<br>(M<sub>age</sub>=65)</td><td>Measured level of<br>cardiorespiratory</td><td>Computerized;<br>Manual<br>(keyboard)</td><td>A single block<br>consisting of 36<br>non-color words</td><td>RTs (in ms)<br>and error rates</td><td>Correlational<br>using CRF as<br>predictor of</td><td>Negative<br>associations<br>between CFR and</td><td>Higher levels of fitness<br>are associated with</td><td>No<br>comparison to<br>a non-color</td></tr></tbody></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td></td><td></td><td>fitness (CRF via a field test)</td><td>with three colored buttons); 3 (green, purple, red)</td><td>items printed in color, 36 color-words items printed in congruent color, 36 eligible color-words items printed in incongruent color, 36 ineligible color-words items printed in incongruent color presented in a counterbalanced order (144 trials in total)</td><td>for each condition</td><td>(single measure of) Stroop performance</td><td>both RTs and error rates to the incongruent-eligible condition</td><td>better attentional control</td><td>words neutral baseline (Issue 1)<br/>No control of the color-congruent items contingency (Issue 2)</td></tr><tr><td>Ramnath et al. (2018) – PLoS ONE</td><td>70 participants (M<sub>age</sub>=71)</td><td>Measured level of physical activity (via the Yale Physical Activity Survey, YPAS) and measured level of fitness and functional performance (via a field test battery assessing grip strength, functional reach, and balance)</td><td>Computerized; Manual (color-coded response button); 4 (red, blue, green, yellow)</td><td>2 blocks consisting of a word-reading condition (color words printed in gray ink), and a color-naming conditions with color-words items printed in incongruent colors (no information about the contingencies)</td><td>Mean RTs and accuracy for the incongruent condition (correct responses, errors, missed responses)</td><td>Correlational using physical activity, physical fitness and functional performance as predictors of (single measure of) Stroop performance</td><td>Positive association between functional performance and the number of correct responses to the incongruent items. No association between physical activity levels and all Stroop Task variables</td><td>Individuals with higher functional performance have better executive functions</td><td>No comparison to a non-color words neutral baseline (Issue 1)<br/>Possible contingency issue (Issue 2)<br/>No direct indicator of inhibition (Issue 7)</td></tr><tr><td>Salas-Gomez et al. (2020) – Frontiers in Human Neuroscience</td><td>206 participants (university students, M<sub>age</sub>=19.6)</td><td>Measured level of physical activity (PA, via the International Physical Activity Questionnaire Short Version, IPAQ-SF)</td><td>Paper and pencil; Vocal; 3 (red, blue, green)</td><td>3 lists (no information about the contingencies): 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 with color-neutral items (colored Xs)</td><td>Number of CR completed in 45 sec for each list</td><td>Correlational using PA as predictor of (single measure of) Stroop performance</td><td>Positive association between PA level and the number of CR in each Stroop condition</td><td>Beneficial relationship between PA and cognition in young adults. Physical activity might improve aspects of executive function such as the ability to inhibit stimuli that trigger automatic responses, cognitive control ability, and mental flexibility in university student</td><td>No comparison to a non-color words neutral baseline (Issue 1)<br/>No direct indicator of inhibition (Issue 7)</td></tr><tr><td>Aly and Kojima (2020) – Psychophysiology</td><td>30 participants (M<sub>age</sub>=21)</td><td>Measured level of physical activity (via International Physical Activity Questionnaire, IPAQ)</td><td>Computerized item-by-item presentation; Manual (Response box</td><td>A single block consisting of 60 color-words items printed in congruent color and</td><td>%ER, mean RTs (in msec) and intraindividual variability (as</td><td>Experimental* comparing (single measure of) Stroop performance as a</td><td>General decrease in response speed (i.e., shortened RTs in each condition and item-type) and</td><td>Physical activity is associated with lower distractibility and better inhibition in the Stroop task</td><td>No comparison to a non-color words neutral baseline (Issue 1)</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><thead><tr><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th><th></th></tr></thead><tbody><tr><td></td><td>resulting in comparison of <strong>more</strong> (N=15) vs. <strong>less</strong> (N=15) active group</td><td>with 4 response keys labeled (in Kanji-characters) as red, green, blue and yellow)</td><td>60 color-words items printed in incongruent color, requiring either color or word meaning identification (cued by a square vs. diamond flanker), presented randomly (240 items in total)</td><td>reflected by mean SDs) observed separately for each condition and item-type</td><td>function of <strong>more</strong> or <strong>less active</strong> group<br/>*determination of groups based on measured levels of PA</td><td><strong>Reduced variability</strong> in more active vs. less group<br/>No significant differences in errors</td><td></td><td>baseline (<strong>Issue 1</strong>)<br/>No control of the color-congruent items contingency (<strong>Issue 2</strong>)<br/>No direct indicator of inhibition (<strong>Issue 7</strong>)</td></tr><tr><td>Boucard et al. (2012) – Journal of Sport and Exercise Psychology</td><td>123 participants: Young (Age=18–28, N=63), young-old (60–70 years old, N=30), and old (71–81 years old, N=30) adults. Each age group subdivided into <strong>active</strong> and <strong>non-active</strong> subgroups</td><td>Median split applied to <strong>measured level of physical fitness</strong> (via accelerometry) resulting in comparison of <strong>active</strong> and <strong>non-active</strong> subgroups</td><td>Paper and pencil/list presentation; Vocal; 3 (red, green, blue)</td><td>3 lists: 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 with color-neutral items (colored Xs)</td><td>%CR completed in 45 sec for each list and magnitudes of <strong>"interference"</strong> computed as [(word reading score × neutral score) / (word reading score + neutral score)] ratio.<br/>Conversion of the raw scores into Z-scores</td><td><strong>Experimental*</strong> comparing (single measure of) Stroop performance as function of age and <strong>active</strong> vs <strong>non-active</strong> group<br/>Additional analyses of mediation<br/>*determination of groups based on measured levels of physical fitness</td><td><strong>Reduced magnitudes of the "interference" in active</strong> as compared <strong>non-active group</strong> - effect mediated by the level of cardiovascular fitness</td><td>Effect of physical activity on <strong>specific executive functions</strong>, especially <strong>inhibition</strong>.<br/><strong>Positive link</strong> between physical activity, <strong>cardiovascular fitness</strong>, and <strong>inhibition</strong> in aging</td></tr><tr><td>Chang et al. (2017) – Journal of Sport and Health Science</td><td>60 participants (M<sub>age</sub>=21.1): Endurance (N=20), martial arts (N=20), and recreational (N=20) athletes</td><td><strong>Measured levels of physical fitness</strong> (cardiovascular fitness, muscular endurance and flexibility, agility and power of motor fitness) (via field tests)</td><td>Paper and pencil/list presentation; Vocal; Not mentioned</td><td>5 lists each consisting of 50 trials: 1 word-reading list with color-words items printed in black; 4 color-naming lists1 with color-words items printed in congruent colors 1 with color-words items printed in incongruent colors, 1 with color-neutral</td><td>Completion times for each condition</td><td><strong>Experimental*</strong> comparing (single measure of) Stroop performance as function of <strong>Endurance</strong> vs <strong>martial arts</strong> vs <strong>recreational</strong> sport group<br/>*determination of groups based on sport practice</td><td>No effect of <strong>physical fitness on any Stroop condition</strong></td><td>No positive <strong>relationship</strong> between sport expertise and general cognitive abilities (notably <strong>perceptual speed</strong> and <strong>executive function</strong> as measured by the Stroop task)</td></tr></tbody></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Gajewski and Falkenstein (2015) – Brain and Cognition</td><td>40 participants (M<sub>age</sub>=73.2):<br/>Measured level of physical activity (assessed via the Lüdenscheid Activity Questionnaire), and measured level of physical fitness (assessed via a test on a bicycle ergometer), resulting in the identification of a "highly active" group (N=20) and a "low active" group (N=20) The groups were matched regarding gender, age, and education</td><td>Computerized version, item-by-item presentation + Paper and pencil/list presentation; Manual for the computerized version with buttons corresponding to each of the four colors; Not mentioned for the paper and pencil version; 4 (red, green, yellow, blue)</td><td>2 blocks each consisting of 52 trials: 26 color-words items printed in congruent colors incongruent and 26 color-words items printed in incongruent colors, presented randomly. The first block was a word-reading condition and the second block was a color-naming condition (color-words in colored ink) (104 trials in total) These two blocks were performed in both the paper and pencil and computerized versions of the task</td><td>Error rate, mean RTs, and individual SDs. An interference index was calculated only in the paper and pencil version by subtracting the time to perform the word-reading condition (block 1) to the time to perform the color-naming condition (block 2)</td><td>Experimental* comparing (single measure of) Stroop performance as function of highly active vs low active group *determination of groups based on measured levels of physical activity</td><td>Higher error rates in the color-naming block and incongruent items for the low-active group No group difference in the RTs Higher interference index for the low active group in comparison to their active counterparts</td><td>These results question the assumption that physical activity enhances inhibitory processing; rather, physical activity is associated with lower distractibility in Stroop interference</td><td>contingency (Issue 2)<br/>No analysis of errors (possibly Issue 4)<br/>Word-reading condition as baseline; No comparison to a non-color words neutral baseline (Issue 1)<br/>No control of the color-congruent items contingency (Issue 2)<br/>Possible practice effect (Issue 6) due to the completion of both computerized and paper version<br/>No direct indicator of inhibition (Issue 7)</td></tr><tr><td>Gajewski et al. (2020) – NeuroImage</td><td>246 participants: young (M<sub>age</sub>=25.1, N=36), middle-aged (M<sub>age</sub>=46.5, N=58), older (M<sub>age</sub>=70.6, N=152) adults</td><td>Measured level of physical activity in the past two years (assessed with the Lüdenscheid Activity Questionnaire), and measured level of physical fitness (assessed with a test on a bicycle ergometer), resulting in the identification of</td><td>Computerized version + Paper and pencil/list presentation; Manual for the computerized version with buttons corresponding to each of the four colors; 3 blocks: 1 word-reading block consisting of 52 trials: 26 color-words items printed in congruent colors incongruent and 26 color-words items printed in incongruent colors, presented randomly;</td><td>Error rate, mean RTs, and individual SDs. An interference index was calculated only in the paper and pencil version by subtracting the time to perform the word-</td><td>Experimental* comparing (single measure of) Stroop performance as function of young vs middle-aged vs older-low performing vs older-mid performing vs</td><td>High performing old adults did not differ from middle-aged-adults in RTs to incongruent items and interference index</td><td>Old high performing adults display executive function levels that are comparable to middle-aged adults</td><td>Word-reading condition as baseline; No comparison to a non-color words neutral baseline (Issue 1)<br/>No control of the color-congruent</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td></td><td></td><td>low-, mid- and high-performing subgroups in old adults</td><td>Not mentioned for the paper and pencil version; 4 (red, green, yellow, blue)</td><td>1 color-naming block consisting of 146 trails: 26 color-words items printed in congruent colors incongruent and 26 color-words items printed in incongruent colors; 1 switching block consisting of 146 trials including word-reading and color-naming items in function of a cue on the screen (146 items). The two first blocks were also performed in the paper and pencil version</td><td>reading condition to the time to perform the color-naming condition</td><td>older-high performing adults group<br/>*determination of groups based on age and measured levels of physical activity</td><td></td><td>items contingency (Issue 2)<br/>Possible practice effect (Issue 6) due to the completion of both computerized and paper version<br/>No control of the color-congruent items contingency (Issue 2)<br/>No direct indicator of inhibition (Issue 7)</td></tr><tr><td>Goenarjo et al. (2020) – International Journal of Environmental Research and Public Health</td><td>56 male participants (M<sub>age</sub>=22.1)</td><td>Measured level of physical activity (via the Global Physical Activity Questionnaire, GPAQ), and Measured level of cardiorespiratory fitness (CRF) (via a graded maximal exercise test) resulting in the identification of an “active” (N=26) and “inactive” (N=30) groups</td><td>Computerized; Manual (color-coded keys on a computer keyboard); 4 (red, blue, green, yellow)</td><td>3 blocks each consisting of 60 trials: 1 with color-words items printed in congruent colors, 1 with color-words items printed in incongruent colors and 1 switching block with color-words items printed in incongruent color, requiring either color or word meaning in function of a cue on the screen</td><td>% of correct responses (%CR) and mean RTs for each condition</td><td>Experimental* comparing (single measure of) Stroop performance as function of active vs inactive group<br/>*determination of groups based on measured levels of physical activity</td><td>Reduced RTs to the switching items for the active group in comparison to the inactive group<br/>No other group difference in RTs in the other conditions and in accuracy</td><td>Physical activity levels are beneficial to executive functioning, especially switching but not inhibition (as reflected by the absence of group effect in the incongruent condition)<br/>No comparison to a non-color words neutral baseline (Issue 1)<br/>No control of the color-congruent items contingency (Issue 2)<br/>No direct indicator of inhibition (Issue 7)<br/>Change in switching performance difficult to interpret in the</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Goenarjo et al. (2021) – Physiology &amp; Behavior</td><td>24 male participants (M<sub>age</sub>=60.4), 2 age groups: 55-60 years old (N=14) and 61-69 years old (N=10)</td><td>Measured level of cardiorespiratory fitness (CRF) (via a graded maximal exercise test) resulting in the identification of a “higher-fit” and “lower-fit” subgroups for each age groups</td><td>Computerized; Manual (color-coded keys on a computer keyboard); 4 (red, blue, green, yellow)</td><td>3 blocks each consisting of 60 trials: 1 with color-words items printed in congruent colors, 1 with color-words items printed in incongruent colors and 1 switching block with color-words items printed in incongruent color, requiring either color or word meaning in function of a cue on the screen</td><td>% of correct responses (%CR) and mean RTs for each condition</td><td>Experimental* comparing (single measure of) Stroop performance as function of higher-fit vs lower-fit group *determination of groups based on measured levels of cardiorespiratory fitness and age</td><td>Reduced RTs to the switching items for the higher-fit 61-69 years old in comparison to lower-fit group No other group difference in RTs in the other conditions and in accuracy</td><td>Positive association between cardiorespiratory fitness and executive functions in older adults</td><td>absence of change in the incongruent items No comparison to a non-color words neutral baseline (Issue 1) No control of the color-congruent items contingency (Issue 2) Change in switching performance difficult to interpret in the absence of change in the incongruent items Low N participants</td></tr><tr><td>O'Brien et al. (2021) – GeroScience</td><td>35 participants</td><td>Measured level of physical activity (PA) (assessed via a step-count device), Measured level of cardiorespiratory fitness (CRF) (via a graded maximal exercise test) resulting in the identification of an Inactive group (N=16, M<sub>age</sub>=68) and Active group (N=19, M<sub>age</sub>=66)</td><td>Computerized, item-by-items presentation; Manual (color-coded keys on a computer keyboard); 4 (red, blue, green, yellow)</td><td>3 blocks each consisting of 60 trials: 1 with color-words items printed in congruent colors, 1 with color-words items printed in incongruent colors and 1 switching block with color-words items printed in incongruent color, requiring either color or word meaning</td><td>Mean RTs (in ms) in each condition, accuracy (not reported in the results because of high accuracy)</td><td>Experimental* comparing (single measure of) Stroop performance as function of Inactive vs Active group *determination of groups based on measured levels of PA and CRF</td><td>Reduced RTs to the switching items for the active group in comparison to the inactive group Negative associations between levels of physical activity and CRF and RTs to the switching condition</td><td>Older active adults had superior cognitive flexibility than their inactive peers; habitual physical activity is an important contributor to executive functions in cognitively healthy older adults</td><td>No comparison to a non-color words neutral baseline (Issue 1) No control of the color-congruent items contingency (Issue 2) Change in switching performance difficult to interpret in the</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Aguirre-Loaiza et al. (2019) – Frontiers in Psychology, Experiment 1*</td><td>54 physically active participants (Mage = 20.7) assigned to the exercise (N=25) vs. control (N=29) group</td><td>45-min session of indoor cycling at 75-85% HRmax (acute aerobic exercise) vs rest (passive control group)</td><td>Paper and pencil/list presentation; Vocal; Not mentioned</td><td>2 lists each consisting of 84 trials: 1 word-reading list with switch to color-naming for highlighted items (Stroop A) and 1 word-reading list with switch to color-naming on the experiment's signal (Stroop B). No information about the word color congruency of the items</td><td>% of correct responses (%CR) and completion times (in sec) in each list</td><td>Experimental analyzing pre-and post-test Stroop performance as a function of acute aerobic exercise vs. control group</td><td>Post-test improvement in %CR on Stroop A list in both groups; Post-test improvement in completion time on Stroop B list in control group</td><td>Results reflect a cognitive reserve in young active participants; the exercise intensity turned out detrimental to inhibitory control</td><td>absence of change in the incongruent items<br/>Low N participants<br/>No comparison to a non-color words neutral baseline (Issue 1)<br/>Possible contingency issue (Issue 2)<br/>Performance of the control group suggests a practice effect (Issue 6)<br/>No direct indicator of inhibition (Issue 7)</td></tr><tr><td>Aguirre-Loaiza et al. (2019) – Frontiers in Psychology, Experiment 2*</td><td>36 physically inactive participants (Mage = 21.6) assigned to the exercise (N=10) vs control (N=26) group</td><td>30-min session of indoor cycling at 75-85% HRmax (acute aerobic exercise) vs rest (passive control group)</td><td>Paper and pencil/list presentation; Vocal; Not mentioned</td><td>2 lists each consisting of 84 trials: 1 word-reading list with switch to color-naming for highlighted items (Stroop A) and 1 word-reading list with switch to color-naming on the experiment's signal (Stroop B). No information about the word color congruency of the items</td><td>% of correct responses (%CR) and completion times (in sec) in each list</td><td>Experimental analyzing pre-and post-test Stroop performance as a function of acute aerobic exercise vs control group</td><td>Post-test improvement in %CR on Stroop A list in exercise group; Post-test improvement in %CR on Stroop B list in control group</td><td>Acute physical exercise tends improve inhibitory control in physically inactive participants,</td><td>No comparison to a non-color words neutral baseline (Issue 1)<br/>Possible contingency issue (Issue 2)<br/>Performance of the control group suggests a practice effect (Issue 6)<br/>No direct indicator of inhibition (Issue 7)</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Barella et al. (2010) – Journal of Aging and Physical Activity</td><td>40 participants (M<sub>age</sub>=69.5) assigned to an Aerobic exercise (N=20) vs Control (N=20) group</td><td>20 min of walking on a treadmill (Acute aerobic exercise group) vs sitting quietly and having a general conversation with the investigator during 25 min (passive control group)</td><td>Computerized; Vocal (RTs were recorded with a sound detection program); 4 (red, green, blue, yellow)</td><td>1 block consisting of 20 color-neutral items (colored Os) and 20 color-words items printed in incongruent color, presented randomly 1 “negative priming” block consisting of 20 color-words items printed in incongruent color (the ink color of each word was the same as the color word stimulus on the previously presented item) (60 items in total)</td><td>Mean RTs per condition and per block</td><td>Experimental analyzing pre- vs immediately after vs 12 times post-intervention* Stroop performance as a function of acute aerobic exercise vs. control activity *the time intervals were: immediately after and 5, 10, 15, 20, 30, 45, 60, 75, 90, 105, and 120 min post-exercise</td><td>Immediate effects: Reduced RTs to the neutral, incongruent, and negative priming items immediately after exercise in comparison to control activity Delayed effects: Reduced RTs to the neutral, incongruent, and negative priming items after both exercise and control activity</td><td>Acute exercise has short-term benefits for speed of processing but does not affect other types of cognitive functioning such as executive function and inhibition in healthy older adults; the absence of difference between the exercise and control conditions in the delayed effects suggests a practice effect</td><td>inhibition (Issue 7)<br/>No comparison to a non-color words neutral baseline (Issue 1)<br/>No analysis of errors (possibly Issue 4)<br/>Lack of control for changes in response speed (possibly Issue 5)<br/>Performance of the control group in the delayed effects suggests a practice effect (Issue 6)<br/>No direct indicator of inhibition (Issue 7)</td></tr><tr><td>Chang et al. (2017) – Psychophysiology</td><td>30 participants (M<sub>age</sub>=22.7): all performed aerobic exercise and control sessions</td><td>20-min steady-state exercise performed at 60–70% of HRR (acute aerobic exercise) vs reading physical activity related books for approximately 30 min (passive control session)</td><td>Computerized; Manual (color-coded buttons on a response pane); 3 (red, blue, green)</td><td>6 color-naming blocks each consisting of 38 color-words items printed in congruent color and 22 color-words items printed in incongruent color (360 trials in total)</td><td>Mean RTs and accuracy for each condition</td><td>Experimental comparing Stroop performance collected after aerobic exercise AND control activity (administered in counter-balanced order 72 hours apart)</td><td>Reduced completion times for congruent and incongruent items after the aerobic exercise activity compared to control No change in accuracy</td><td>Moderate intensity acute exercise results in a generalized rather than selective (i.e., executive) improvement in cognition</td><td>No comparison to a non-color words neutral baseline (Issue 1)<br/>No control of the color-congruent items contingency (Issue 2)<br/>No direct indicator of</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Chang and Etnier (2009a) – Psychology of Sport and Exercise</td><td>41 participants (M<sub>age</sub>=49.1 assigned to a Resistance exercise (N=22) vs Control (N=19) group</td><td>2 sets of 10 repetitions for 6 exercises (acute resistance exercise, 45 min) vs reading a pamphlet related to resistance exercise (passive control) session</td><td>Not mentioned; Vocal; Not mentioned</td><td>3 lists (no information about the contingencies): 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 with color-neutral items (colored rectangles)</td><td>Completion times for each condition</td><td>Experimental analyzing pre- and post-test Stroop performance as a function of acute resistance exercise vs. control group</td><td>Reduced completion times for the word-reading and neutral items lists after the resistance exercise activity compared to control</td><td>Acute resistance exercise benefits speed of processing but not inhibition</td><td>executive function due to the lack of relevant comparisons (Issue 7)<br/>No comparison to a non-color words neutral baseline (Issue 1)<br/>No analysis of errors (possibly Issue 4)<br/>Lack of control for changes in response speed (possibly Issue 5)</td></tr><tr><td>Chang and Etnier (2009b) – Journal of Sport and Exercise Psychology</td><td>65 participants (M<sub>age</sub>=25.9) assigned to a 40% intensity (N=16), 70% intensity (N=16), 100% intensity (N=17) vs Control (N=16) group</td><td>2 sets of 10 repetitions for each of six muscle groups (Acute resistance exercise, 3 separate experimental groups, 40%, 70%, and 100%) vs watching a video on resistance exercise training (passive control group)</td><td>Paper and pencil/list presentation; Vocal – In case of mistake, the examiner said “incorrect”, pointed to the stimulus that resulted in the mistake and the participant was instructed correct his/her mistake and then to continue; Not mentioned</td><td>3 lists (50 trials each): 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 with color-neutral items (colored rectangles)</td><td>Completion times for each condition</td><td>Experimental analyzing pre- and post-test Stroop performance as a function of acute resistance exercise vs. control group</td><td>Reduced completion times for the neutral items lists after all exercise conditions compared to control and reduced completion times for the incongruent items list after the moderate (70%) intensity exercise</td><td>There is a dose-response relationship between the intensity of resistance exercise and cognitive performance: high-intensity exercise benefits speed of processing, but moderate intensity exercise is most beneficial for executive function (as assessed by the incongruent condition)</td><td>No comparison to a non-color words neutral baseline (Issue 1)<br/>No control of the color-congruent items contingency (Issue 2)<br/>No analysis of errors (possibly Issue 4)<br/>No direct indicator of executive function due to the lack of relevant comparisons (Issue 7)</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Chang et al. (2014) – Journal of Science and Medicine in Sport</td><td>30 participants (M<sub>age</sub>=58.1): All performed Resistance exercise and Control sessions</td><td>2 sets of 7 resistance exercises (Acute resistance exercise) vs reading materials related to physical activity and mental health (passive control) session</td><td>Paper and pencil/list presentation; Vocal; Not mentioned</td><td>5 lists each consisting of 50 trials: 1 word-reading list with color-words items printed in black; 4 color-naming lists1 with color-words items printed in congruent colors, 1 with color-words items printed in incongruent colors, 1 with color-neutral word items printed in color and 1 with color-neutral items (colored squares)</td><td>Completion times for each condition</td><td>Experimental comparing Stroop performance collected after resistance exercise AND control activity (administered in counter-balanced order 48 hours apart)</td><td>Reduced completion times for all Stroop lists after the exercise session compared to the control session; largest difference between pre-test RT and post-test RT as a function of exercise for the incongruent condition</td><td>Acute resistance exercise facilitates general cognition but has a more beneficial effect on processes involving executive control</td><td>comparisons (Issue 7)<br/>No computation of the Stroop interference despite the use of a color-neutral words condition<br/>No control of the color-congruent items contingency (Issue 2)<br/>No analysis of errors (possibly Issue 4)<br/>No direct indicator of executive function due to the lack of relevant comparisons (Issue 7)</td></tr><tr><td>Johnson et al. (2016) – Journal of Aging and Physical Activity</td><td>31 participants (M<sub>age</sub>=71.7) assigned to the Aerobic group (N=17) vs Resistance group (N=14)</td><td>Intense cycling session on an ergometer (acute aerobic exercise) vs 5 strength exercises on machines (acute resistance exercise): No control group<br/>Each group performed 10- min and 30-min duration sessions one week apart</td><td>Computerized; Vocal (RTs were recorded with a sound detection program); 4 (red, blue, green, yellow)</td><td>3 blocks each consisting of 20 trials: 1 with color-words items printed in incongruent colors, 1 with color-neutral items (colored Xs), and 1 with two successive similar color-word items printed in incongruent colors (negative priming list)</td><td>Mean RTs per condition and per block</td><td>Experimental comparing Stroop performance collected immediately, 30 minutes, and 60 minutes after 10min duration AND 30min duration acute aerobic exercise vs 10min duration AND 30min duration resistance exercise</td><td>Reduced RTs to the negative priming condition immediately post-exercise, independently of the group (aerobic or resistance) or exercise bout duration At 60 min post-exercise, reduced RTs to the neutral items after the 10 min exercise bout</td><td>The improved performance in the negative priming condition suggests that an acute bout of exercise can improve cognitive performance, and in particular, the more complex executive functioning (i.e., inhibition) in older adults</td><td>No comparison to a non-color words neutral baseline (Issue 1)<br/>No control of the color-congruent items contingency (Issue 2)<br/>No analysis of errors (possibly Issue 4)</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Sibley et al. (2006) – Journal of Sport and Exercise Psychology</td><td>79 participants (M<sub>age</sub>=22.5)</td><td>20 min of self-paced moderate-intensity exercise on a treadmill (Acute aerobic exercise) vs sitting quietly and reading material (passive control activity)</td><td>Computerized (Stimuli were presented in list format); Vocal; 4 (red, blue, green, yellow)</td><td>3 color-naming lists each consisting of 30 items: 1 with color-neutral items (colored Xs), 1 with color-words items printed in incongruent colors, and 1 with two successive similar color-word items printed in incongruent colors (negative priming list)</td><td>Completion times (in sec) in each list, errors (not reported because of high accuracy)</td><td>Experimental comparing Stroop performance collected after acute aerobic exercise AND after control activity (administered in counter-balanced order 7 days apart)</td><td>Reduced completion times in the incongruent list after exercise. Significant order*session interaction for all Stroop conditions showing that participants had faster responses in the second session; No significant change in the two other lists</td><td>The session effect suggests a learning or practice effect. Acute exercise leads to an improvement in executive functioning related to maintenance of goal-oriented processing, but not in processing speed and inhibition</td><td>Possible practice effect (Issue 6)<br/>Change in negative priming difficult to interpret in the absence of change in the incongruent items<br/>Low N participants<br/>No comparison to a non-color words neutral baseline (Issue 1)<br/>Practice effect (Issue 6)<br/>No analyses of pre-session RTs</td></tr><tr><td>Sugimoto et al. (2020) – Physiological Reports</td><td>20 participants (M<sub>age</sub>=21); all performed Repeated exercise bout and Single exercise bout sessions</td><td>2 20-min bouts, separated by a 20-min sitting rest (Repeated Exercise, R-EX)) vs 1 40-min bout (Single Exercise bout, S-EX) (Acute moderate intensity aerobic exercise); no control group</td><td>Computerized, item-by-item presentation; Manual (color-labeled keypad); 4 (red, blue, green, yellow)</td><td>3 lists each consisting of 24 trials: 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in congruent colors and 1 with color-words items printed in incongruent colors</td><td>Reaction times and response accuracy; Calculation of the “reverse-Stroop interference” score: (RTincongruent – RTword reading) / RTword reading x 100</td><td>Experimental comparing Stroop performance collected before, immediately after, 10 min after vs 30 min after the Repeated AND Single exercise (administered in counter-balanced order 72 hours apart)</td><td>Reduced RTs to the word-reading and congruent list immediately post exercise; this reduction remained after until 10min post-exercise<br/>Reduction of the reverse-Stroop interference score, immediately post exercise</td><td>Both repeated exercise and single exercise bouts have beneficial immediate effects on inhibitory control</td><td>Word-reading condition as baseline; No comparison to a non-color words neutral baseline (Issue 1)<br/>No control of the color-congruent items contingency (Issue 2)</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Tomoo et al. (2020) – Physiological Reports</td><td>22 male participants (M<sub>age</sub>=21.2); all performed the High-Intensity resistance exercise condition and the High-Volume low-intensity resistance exercise</td><td>High-Intensity resistance exercise condition (HRE) (70% of 1-RM) vs High-Volume low-intensity resistance exercise condition (HV-LRE) (35% of 1-RM) (Acute resistance exercise); no control group</td><td>Computerized, item-by-item presentation; Not mentioned; 4 (red, blue, green, yellow)</td><td>3 lists each consisting of 24 trials: 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in congruent colors and 1 with color-words items printed in incongruent colors</td><td>Reaction time and response accuracy; Calculation of the “reverse-Stroop interference” score: (RTincongruent – RTword reading) / RTword reading x 100</td><td>Experimental comparing Stroop performance collected before, immediately after, 10 min, 20 min after, after vs 30 min after the High Intensity AND Low intensity exercise (administered in counter-balanced order 72 hours apart)</td><td>Reduced RTs to all lists immediately post exercise; this reduction remained after until 10min post-exercise for the word-reading and incongruent list and 20min for the congruent list<br>Reduction of the reverse-Stroop interference score; this reduction remained after until 30 min post-exercise</td><td>The two resistance training interventions have beneficial immediate effects on inhibitory control</td><td>Possible practice effect (Issue 6)<br>No direct indicator of inhibition (Issue 7)<br>Word-reading condition as baseline; No comparison to a non-color words neutral baseline (Issue 1)<br>No control of the color-congruent items contingency (Issue 2)<br>Possible practice effect (Issue 6)<br>No direct indicator of inhibition (Issue 7)</td></tr><tr><td>Zimmer et al. (2016) – European Journal of Applied Physiology</td><td>121 participants (M<sub>age</sub>=23.8) assigned to Low intensity (N=30), Moderate intensity (N=30), High intensity (N=31) vs control group (N=30)</td><td>Low vs moderate vs high intensity exercise bouts (acute aerobic exercise) vs supervised low-intensity myofascial relaxation training (active control group)</td><td>Computerized item-by-item presentation; Manual (keyboard with four colored buttons); 4 (red, green, blue, yellow)</td><td>4 blocks each consisting of 128 trials per condition: 1 word-reading block consisting of color-words presented in colored ink; 2 color-naming blocks: 1 consisting of colored rectangles and 1 with color-words items printed in incongruent colors; 1 reverse condition</td><td>Mean RTs (in ms); medians of RTs at word-reading baseline and naming baseline (colored rectangles). A software computes the Stroop effect by subtracting RTnaming from median RT of each Stroop</td><td>Experimental analyzing pre-vs post-intervention Stroop performance as a function of acute aerobic exercise (3 intensities) vs control<br>Additional analyses of serum 5-HT concentrations - not discussed here</td><td>Reduced RTs to the word-reading condition after high-intensity exercise in comparison to low-intensity exercise<br>A non-significant tendency for a RT reduction to the “Reverse Stroop effect” after Low Intensity in comparison to the moderate intensity exercise</td><td>Exercise intensity (and subsequent enhanced serum 5-HT levels) leads to improved response inhibition as reflected by the changes in the reading and the reverse Stroop effect</td><td>Word-reading condition as baseline; No comparison to a non-color words neutral baseline (Issue 1)<br>No control of the color-congruent items contingency (Issue 2)</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td></td><td></td><td></td><td>(word-reading<br/>incongruent items).</td><td>condition;<br/>Computation of<br/>the "Reverse<br/>Stroop effect"<br/>as the balance<br/>between<br/>median RT at<br/>Stroop<br/>condition and<br/>RT at reading<br/>condition</td><td></td><td>No analysis of<br/>errors<br/>(possibly Issue<br/>4)</td></tr><tr><td>Kim (2015) –<br/>Journal of<br/>Exercise<br/>Nutrition &<br/>Biochemistry</td><td>14 participants<br/>(M<sub>age</sub>=20.6)<br/>assigned to the<br/>Exercise group<br/>(N=7) vs the<br/>Control group<br/>(N=7)</td><td>8-week Taekwondo<br/>training program<br/>(85-minute sessions, 5<br/>sessions per week);<br/>No information about<br/>the control group<br/>intervention</td><td>Paper and<br/>pencil/list<br/>presentation;<br/>Vocal; 3 (red,<br/>green, blue)</td><td>3 lists:<br/>1 word-reading list<br/>with color-words<br/>items printed in<br/>black; 2 color-<br/>naming lists: 1 with<br/>color-words items<br/>printed in<br/>incongruent colors<br/>and 1 with color-<br/>neutral items<br/>(colored Xs)</td><td>Number of<br/>correct<br/>responses in 45<br/>seconds for<br/>each condition</td><td>Possible<br/>practice effect<br/>(Issue 6)</td></tr><tr><td></td><td></td><td></td><td></td><td></td><td>Experimental<br/>analyzing pre-<br/>and post-test<br/>Stroop<br/>performance as a<br/>function of<br/>training program<br/>vs. control group</td><td>No direct<br/>indicator of<br/>inhibition<br/>(Issue 7)</td></tr><tr><td></td><td></td><td></td><td></td><td></td><td>Post-test<br/>improvement in<br/>number of correctly<br/>identified items in<br/>the word-reading<br/>and neutral lists<br/>No significant<br/>change in the<br/>incongruent<br/>condition</td><td>No<br/>comparison to<br/>a non-color<br/>words neutral<br/>baseline (Issue<br/>1)</td></tr><tr><td></td><td></td><td></td><td></td><td></td><td></td><td>Lack of<br/>control for<br/>changes in<br/>response speed<br/>(possibly Issue<br/>5)</td></tr><tr><td></td><td></td><td></td><td></td><td></td><td></td><td>Low N<br/>participants</td></tr><tr><td>Ludyga et al.<br/>(2019) – Journal<br/>of Science and<br/>Medicine in Sport</td><td>35 participants<br/>(Age=12-15)<br/>assigned to<br/>Physical<br/>training group<br/>(N=19) vs<br/>Control group<br/>(N=16)</td><td>8-week physical<br/>training program<br/>(20-min exercise<br/>sessions, moderate<br/>intensity aerobic and<br/>coordinative<br/>exercise), 5 days a<br/>week vs social<br/>interaction with<br/>classmates during the<br/>intervention groups'<br/>exercise sessions<br/>(passive control<br/>group)</td><td>Computerized;<br/>Manual<br/>(button on a<br/>response box);<br/>Not<br/>mentioned</td><td>4 blocks each<br/>consisting of 36<br/>trials including 18<br/>color-words items<br/>printed in<br/>congruent color and<br/>18 color-words<br/>items printed in<br/>incongruent color<br/>presented randomly<br/>(144 trials in total)</td><td>Accuracy rates<br/>and RTs (in<br/>ms) in the<br/>incongruent<br/>condition</td><td>No control<br/>of<br/>the color-<br/>congruent<br/>items<br/>contingency<br/>(Issue 2)</td></tr><tr><td></td><td></td><td></td><td></td><td></td><td>Experimental<br/>analyzing pre-<br/>vs. post-<br/>intervention<br/>Stroop<br/>performance as<br/>function of<br/>physical<br/>training vs<br/>passive control</td><td>Improvement<br/>consistent with<br/>a normal<br/>developmental<br/>trajectory;</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Iuliano et al. (2015) – Experimental Gerontology</td><td>80 participants (M<sub>age</sub>=67) assigned to the Resistance training group (N=20), Cardiovascular training group (N=20), Postural training group (N=20) vs Control group (N=20)</td><td>12-week training program (cardiovascular, resistance, postural), 3 sessions/week vs no intervention (passive control group)</td><td>Not mentioned; Vocal; 3 (red, green, blue)</td><td>3 lists: 1 word-reading list with color-words items printed in black (T1); 2 color-naming lists: 1 with color-neutral items (colored circles) (T2) and 1 with color-words items printed in incongruent colors (T3)</td><td>Number of correct responses in 45 seconds for each condition; the Stroop interference was calculated as: (T3 - (T1 + T2))/2; only the interference scores are reported</td><td>Experimental analyzing pre- and post-test Stroop performance as a function of cardiovascular vs resistance vs postural training programs vs control</td><td>No change in Stroop performance for either group</td><td>The interventions did not lead to significant improvements in executive functions (and notably selective attention, visual attention, and inhibitory control as measured by the Stoop task)</td><td>Lack of control for changes in response speed (possibly Issue 5)<br/>No direct indicator of inhibition (Issue 7)<br/>Low N participants</td></tr><tr><td>Maillot et al. (2012) – Psychology and Aging</td><td>30 participants (M<sub>age</sub>=73.5) assigned to Intervention group (N=15) vs Control group (N=16)</td><td>12-week active video game (exergames) training program (one-hour sessions, twice a week) vs no intervention (passive control group)</td><td>Not mentioned; Vocal; Not mentioned</td><td>4 lists: 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 consisting of colored Xs; 1 switching list including word-reading and color-naming incongruent items in function of a cue</td><td>Number of correct responses in 45 seconds to the incongruent and flexibility conditions; A “change score” was calculated by subtracting the pretest score from the posttest score for the incongruent and flexibility conditions</td><td>Experimental analyzing pre- vs. post- intervention (6 months) Stroop performance as function of physical training vs passive control</td><td>Greater change score in both the incongruent and flexibility lists after the training program than control for both</td><td>Exergames training is beneficial to executive functions</td><td>Word-reading condition as baseline; No comparison to a non-color words neutral baseline (Issue 1)<br/>No direct indicator of inhibition (Issue 7)<br/>No comparison to a non-color words neutral baseline (Issue 1)<br/>No direct indicator of inhibition (Issue 7)<br/>Low N participants</td></tr><tr><td>Predovan et al. (2012) – Journal</td><td>67 participants (M<sub>age</sub>=67.9) assigned to the</td><td>12-week aerobic training program (60-min sessions, 45 lists each consisting 100 trials: 1 word-</td><td>Paper and pencil/list presentation;</td><td>Mean RTs and accuracy for each condition;</td><td>Experimental* analyzing pre- vs. post-</td><td>Reduced post-test RTs and greater change score in the</td><td>The benefits of an aerobic training program occur</td><td>No comparison to a non-color words neutral baseline (Issue 1)<br/>No direct indicator of executive function due to the lack of relevant comparisons (Issue 7)<br/>Low N participants</td><td>No comparison to a non-color words neutral baseline (Issue 1)<br/>No direct indicator of inhibition (Issue 7)<br/>No comparison to a non-color words neutral baseline (Issue 1)<br/>No direct indicator of inhibition (Issue 7)<br/>Low N participants</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>of Aging Research</td><td>Intervention group (N=32) vs Control group (N=35)</td><td>three sessions per week) vs no training intervention (passive control group)</td><td>Vocal; 5 (black, red, blue, green, yellow)</td><td>reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 with color-neutral items (colored rectangles); 1 switching list with color-words items printed in incongruent color, requiring either color or word meaning identification (cued by a square)</td><td>For each Stroop condition, a score measuring the amount of change between the pre- and post-test was computed as follows: pre-test minus post-test score</td><td>intervention Stroop performance as function of physical training vs passive control * determination of groups based on participants' order of recruitment and their willingness to engage in training program</td><td>switching list after exercise in comparison to control</td><td>primarily on executive functions (inhibition and shifting). The absence of change in the incongruent condition suggests that the improvement occurs in the switching domain</td><td>words neutral baseline (Issue 1) Lack of control for changes in response speed (possibly Issue 5) No direct indicator of inhibition (Issue 7)</td></tr><tr><td>Castelli et al. (2011) – Preventive Medicine</td><td>59 participants (M<sub>age</sub>=8.8)</td><td>9-month 120-minute daily school-based physical training program (Participants wore a heart rate monitor during the physical exercise session); no control group</td><td>Not mentioned; Vocal; Not mentioned</td><td>3 lists: 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 with color-neutral items (colored Xs)</td><td>Number of correct responses in 45 seconds for each condition; Computation of an interference score with a software (Not reported in the results; no details about its calculation)</td><td>Experimental analyzing pre- and post-test Stroop performance as a function of physical training</td><td>Post-test improvement in correct responses in all Stroop conditions. Positive associations between the percentage of time spent above the target heart zone during the training program and performance in the incongruent condition</td><td>The time spent at high heart rate during physical activity sessions (suggesting vigorous physical activity) is beneficial to executive functions</td><td>No comparison to a non-color words neutral baseline (Issue 1) Improvement consistent with a normal developmental trajectory; Lack of control for changes in response speed (possibly Issue 5) No direct indicator of executive function due to the lack of relevant comparisons (Issue 7)</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td>Kvalø et al. (2017) – Scandinavian Journal of Medicine & Science in Sports</td><td>429 participants (Age=10-11) assigned to Physical training group (N=217) vs Control group (N=212)</td><td>10-month school-based physical training program (325 minutes of physical activities per week) vs regular mandatory national curriculum of 135 minutes of physical activity (active control group)</td><td>Not mentioned; Vocal; Not mentioned</td><td>3 lists: 1 word-reading list with color-words items printed in black; 2 color-naming lists: 1 with color-words items printed in incongruent colors and 1 with color-neutral items (colored patches)</td><td>Number of CR completed in 45 sec for each list</td><td>Experimental analyzing pre-vs post-intervention Stroop performance as function of physical training vs active control</td><td>Increased number of CR to colored patches items list in both the physical training and control groups. No significant change in the other lists. Non-significant tendency for a time×group interaction in the total number of CR in the 3 cumulated lists</td><td>Increased physical activity in school resulted in a non-significant tendency to benefit children's executive function</td><td>No comparison to a non-color words neutral baseline (Issue 1)<br>Improvement consistent with a normal developmental trajectory; Lack of control for changes in response speed (possibly Issue 5)<br>No direct indicator of executive function due to the lack of relevant comparisons (Issue 7)</td></tr><tr><td>Smiley-Oyen et al. (2008) – Annals of Behavioral Medicine</td><td>57 participants (Age=65-79) assigned to a Cardiovascular exercise training group (N=28) vs a Flexibility and Resistance training group (N=29)</td><td>10-month training program including cardiovascular exercise vs flexibility and resistance exercise (no passive control group)</td><td>Computerized; Manual (pressing 1, 2, 3 keys on a computer keyboard); 3 (red, blue, green)</td><td>3 blocks each consisting of 100 trials: 1 word-reading block consisting of color-words presented in colored ink; 2 color-naming blocks: 1 with color-words items printed in incongruent colors and 1 with color-neutral items (undefined)</td><td>Error rates and mean RTs for each condition</td><td>Experimental analyzing pre-vs midpoint vs post-intervention Stroop performance as function of cardiovascular training vs flexibility and resistance training</td><td>Reduced post-test RTs to incongruent items in the cardiovascular training group compared to the flexibility and resistance group. No significant change in the two other Stroop blocks<br>Increased error rates in the incongruent items at post intervention in comparison to midpoint in the flexibility and resistance group.</td><td>Cardiovascular (aerobic) exercise in older adults has beneficial effect on executive control, especially inhibition</td><td>No comparison to a color-neutral baseline (Issue 1)<br>No direct indicator of inhibition (Issue 7)</td></tr></table>
Running head: Examining attentional boost in the Stroop task

<table><tr><td><strong>Liu-Ambrose et al. (2008) –</strong><br>Journal of the<br>American<br>Geriatrics Society</td><td>52 participants<br>(M<sub>age</sub>=69.6)<br>assigned to the<br>Intervention<br>group (N=28)<br>vs the Control<br>group (N=24)</td><td>12-month home-based<br>balance and strength<br>exercise <strong>training program</strong> vs<br>administration of<br>clinical care<br>recommendations<br>(<strong>passive control group</strong>)</td><td>Paper and<br>pencil/list<br>presentation;<br>Vocal; Not<br>mentioned</td><td>A single block of<br>color-words items<br>printed in<br>incongruent colors<br>(112 trials)</td><td>Number of<br>correct<br>responses and<br>the total time to<br>complete the<br>task</td><td><strong>Experimental</strong><br>analyzing pre-<br>vs. midpoint<br>intervention (6<br>months) Stroop<br>performance as<br>function of<br><strong>physical<br>training</strong> vs<br>passive <strong>control</strong><br>(no measure at<br>post-test)</td><td><strong>Reduced error<br>rates in the<br>incongruent items</strong><br>at mid-point and post<br>intervention in<br>comparison to pre-<br>intervention in the<br><strong>cardiovascular<br>training group</strong></td><td>The home-based<br>resistance and balance<br>training program<br>improved <strong>executive<br>functioning</strong>,<br>specifically response<br><strong>inhibition</strong>, after 6<br>months</td><td>No<br>comparison to<br>a color-neutral<br>baseline (<strong>Issue<br>1</strong>)<br><br>No direct<br>indicator of<br>inhibition<br>(<strong>Issue 7</strong>)</td></tr></table>

Note. Light gray background indicates an “overinterpretation” of reported results and dark gray indicates a clear mismatch between empirical results and their interpretation.

*Same study but two different experiments; the general design of the study is quasi-experimental: participants completed a physical activity questionnaire (IPAQ) to determine whether participants were physically active (study 1) or physically inactive (study 2).
References (Table 2S)

Aadland, K. N., Moe, V. F., Aadland, E., Anderssen, S. A., Resaland, G. K., & Ommundsen, Y. (2017). Relationships between physical activity, sedentary time, aerobic fitness, motor skills and executive function and academic performance in children. *Mental Health and Physical Activity, 12*, 10–18. https://doi.org/10.1016/j.mhpa.2017.01.001

Aguirre-Loaiza, H., Arenas, J., Arias, I., Franco-Jímenez, A., Barbosa-Granados, S., Ramos-Bermúdez, S., Ayala-Zuluaga, F., Núñez, C., & García-Mas, A. (2019). Effect of Acute Physical Exercise on Executive Functions and Emotional Recognition: Analysis of Moderate to High Intensity in Young Adults. *Frontiers in Psychology, 10*, 2774. https://doi.org/10.3389/fpsyg.2019.02774

Aly, M., & Kojima, H. (2020). Relationship of regular physical activity with neuroelectric indices of interference processing in young adults. *Psychophysiology, 57*(12), e13674. https://doi.org/10.1111/psyp.13674

Barella, L. A., Etnier, J. L., & Chang, Y.-K. (2010). The Immediate and Delayed Effects of an Acute Bout of Exercise on Cognitive Performance of Healthy Older Adults. *Journal of Aging and Physical Activity, 18*(1), 87–98. https://doi.org/10.1123/japa.18.1.87

Bixby, W. R., Spalding, T. W., Haufler, A. J., Deeny, S. P., Mahlow, P. T., Zimmerman, J. B., & Hatfield, B. D. (2007). The Unique Relation of Physical Activity to Executive Function in Older Men and Women. *Medicine & Science in Sports & Exercise, 39*(8), 1408–1416. https://doi.org/10.1249/mss.0b013e31806ad708

Boucard, G. K., Albinet, C. T., Bugaiska, A., Bouquet, C. A., Clarys, D., & Audiffren, M. (2012). Impact of Physical Activity on Executive Functions in Aging: A Selective Effect on Inhibition Among Old Adults. *Journal of Sport and Exercise Psychology, 34*(6), 808–827. https://doi.org/10.1123/jsep.34.6.808
Running head: Examining attentional boost in the Stroop task

Castelli, D. M., Hillman, C. H., Hirsch, J., Hirsch, A., & Drollette, E. (2011). FIT Kids: Time in target heart zone and cognitive performance. *Preventive Medicine*, 52, S55-S59.

https://doi.org/10.1016/j.ypmed.2011.01.019

Chang, E. C.-H., Chu, C.-H., Karageorghis, C. I., Wang, C.-C., Tsai, J. H.-C., Wang, Y.-S., & Chang, Y.-K. (2017). Relationship between mode of sport training and general cognitive performance. *Journal of Sport and Health Science*, 6(1), 89-95.

https://doi.org/10.1016/j.jshs.2015.07.007

Chang, Y.-K., Alderman, B. L., Chu, C.-H., Wang, C.-C., Song, T.-F., & Chen, F.-T. (2017). Acute exercise has a general facilitative effect on cognitive function: A combined ERP temporal dynamics and BDNF study. *Psychophysiology*, 54(2), 289-300.

https://doi.org/10.1111/psyp.12784

Chang, Y.-K., & Etnier, J. L. (2009a). Effects of an acute bout of localized resistance exercise on cognitive performance in middle-aged adults: A randomized controlled trial study. *Psychology of Sport and Exercise*, 10(1), 19-24.

https://doi.org/10.1016/j.psychsport.2008.05.004

Chang, Y.-K., & Etnier, J. L. (2009b). Exploring the Dose-Response Relationship between Resistance Exercise Intensity and Cognitive Function. *Journal of Sport and Exercise Psychology*, 31(5), 640-656. https://doi.org/10.1123/jsep.31.5.640

Chang, Y.-K., Tsai, C.-L., Huang, C.-C., Wang, C.-C., & Chu, I.-H. (2014). Effects of acute resistance exercise on cognition in late middle-aged adults: General or specific cognitive improvement? *Journal of Science and Medicine in Sport*, 17(1), 51-55.

https://doi.org/10.1016/j.jsams.2013.02.007

Gajewski, P. D., & Falkenstein, M. (2015). Long-term habitual physical activity is associated with lower distractibility in a Stroop interference task in aging: Behavioral and ERP
Running head: Examining attentional boost in the Stroop task

evidence. *Brain and Cognition*, 98, 87–101.

https://doi.org/10.1016/j.bande.2015.06.004

Gajewski, P. D., Falkenstein, M., Thönes, S., & Wascher, E. (2020). Stroop task performance across the lifespan: High cognitive reserve in older age is associated with enhanced proactive and reactive interference control. *NeuroImage*, 207, 116430.

https://doi.org/10.1016/j.neuroimage.2019.116430

Goenarjo, R., Bosquet, L., Berryman, N., Metier, V., Perrochon, A., Fraser, S. A., & Dupuy, O. (2020). Cerebral Oxygenation Reserve: The Relationship Between Physical Activity Level and the Cognitive Load During a Stroop Task in Healthy Young Males.

*International Journal of Environmental Research and Public Health*, 17(4), Article 4.

https://doi.org/10.3390/ijerph17041406

Goenarjo, R., Dupuy, O., Fraser, S., Berryman, N., Perrochon, A., & Bosquet, L. (2021). Cardiorespiratory fitness and prefrontal cortex oxygenation during Stroop task in older males. *Physiology & Behavior*, 242, 113621.

https://doi.org/10.1016/j.physbeh.2021.113621

Iuliano, E., di Cagno, A., Aquino, G., Fiorilli, G., Mignogna, P., Calcagno, G., & Di Costanzo, A. (2015). Effects of different types of physical activity on the cognitive functions and attention in older people: A randomized controlled study. *Experimental Gerontology*, 70, 105–110. https://doi.org/10.1016/j.exger.2015.07.008

Johnson, L., Addamo, P. K., Selva Raj, I., Borkoles, E., Wyckelsma, V., Cyarto, E., & Polman, R. C. (2016). An Acute Bout of Exercise Improves the Cognitive Performance of Older Adults. *Journal of Aging and Physical Activity*, 24(4), 591–598.

https://doi.org/10.1123/japa.2015-0097
Running head: Examining attentional boost in the Stroop task

Kim, Y. (2015). The effect of regular Taekwondo exercise on Brain-derived neurotrophic factor and Stroop test in undergraduate student. *Journal of Exercise Nutrition & Biochemistry, 19*(2), 73–79. https://doi.org/10.5717/jenb.2015.15060904

Kvalø, S. E., Bru, E., Brønnick, K., & Dyrstad, S. M. (2017). Does increased physical activity in school affect children’s executive function and aerobic fitness? *Scandinavian Journal of Medicine & Science in Sports*, 27(12), 1833–1841.

https://doi.org/10.1111/sms.12856

Liu-Ambrose, T., Donaldson, M. G., Ahamed, Y., Graf, P., Cook, W. L., Close, J., Lord, S. R., & Khan, K. M. (2008). Otago Home-Based Strength and Balance Retraining Improves Executive Functioning in Older Fallers: A Randomized Controlled Trial. *Journal of the American Geriatrics Society*, 56(10), 1821–1830.

https://doi.org/10.1111/j.1532-5415.2008.01931.x

Ludyga, S., Köchli, S., Pühse, U., Gerber, M., & Hanssen, H. (2019). Effects of a school-based physical activity program on retinal microcirculation and cognitive function in adolescents. *Journal of Science and Medicine in Sport*, 22(6), 672–676.

https://doi.org/10.1016/j.jsams.2018.11.029

Maillot, P., Perrot, A., & Hartley, A. (2012). Effects of interactive physical-activity video-game training on physical and cognitive function in older adults. *Psychology and Aging*, 27(3), 589–600. https://doi.org/10.1037/a0026268

O’Brien, M. W., Kimmerly, D. S., & Mekari, S. (2021). Greater habitual moderate-to-vigorous physical activity is associated with better executive function and higher prefrontal oxygenation in older adults. *GeroScience*, 43(6), 2707–2718.

https://doi.org/10.1007/s11357-021-00391-5

Prakash, R. S., Voss, M. W., Erickson, K. I., Lewis, J. M., Chaddock, L., Malkowski, E., Alves, H., Kim, J., Szabo, A., White, S. M., Wójcicki, T. R., Klamm, E. L., McAuley,
Running head: Examining attentional boost in the Stroop task

E., & Kramer, A. F. (2011). Cardiorespiratory fitness and attentional control in the aging brain. *Frontiers in Human Neuroscience, 4*, 229.

https://doi.org/10.3389/fnhum.2010.00229

Predovan, D., Fraser, S. A., Renaud, M., & Bherer, L. (2012). The Effect of Three Months of Aerobic Training on Stroop Performance in Older Adults. *Journal of Aging Research, 2012*, 1–7. https://doi.org/10.1155/2012/269815

Ramnath, U., Rauch, L., Lambert, E. V., & Kolbe-Alexander, T. L. (2018). The relationship between functional status, physical fitness and cognitive performance in physically active older adults: A pilot study. *PLOS ONE*, 13(4), e0194918.

https://doi.org/10.1371/journal.pone.0194918

Salas-Gomez, D., Fernandez-Gorgojo, M., Pozueta, A., Diaz-Ceballos, I., Lamarain, M., Perez, C., Kazimierczak, M., & Sanchez-Juan, P. (2020). Physical Activity Is Associated With Better Executive Function in University Students. *Frontiers in Human Neuroscience*, *14*, 11. https://doi.org/10.3389/fnhum.2020.00011

Sibley, B. A., Etnier, J. L., & Le Masurier, G. C. (2006). Effects of an Acute Bout of Exercise on Cognitive Aspects of Stroop Performance. *Journal of Sport and Exercise Psychology*, 28(3), 285–299. https://doi.org/10.1123/jsep.28.3.285

Smiley-Oyen, A. L., Lowry, K. A., Francois, S. J., Kohut, M. L., & Ekkekakis, P. (2008). Exercise, Fitness, and Neurocognitive Function in Older Adults: The “Selective Improvement” and “Cardiovascular Fitness” Hypotheses. *Annals of Behavioral Medicine*, 36(3), 280–291. https://doi.org/10.1007/s12160-008-9064-5

Sugimoto, T., Suga, T., Tsukamoto, H., Tomoo, K., Dora, K., Hashimoto, T., & Isaka, T. (2020). Effect of repeated bouts versus a single bout of moderate-intensity exercise on postexercise inhibitory control. *Physiological Reports*, 8(15), e14528.

https://doi.org/10.14814/phy2.14528
Tomoo, K., Suga, T., Sugimoto, T., Tanaka, D., Shimoho, K., Dora, K., Mok, E., Matsumoto, S., Tsukamoto, H., Takada, S., Hashimoto, T., & Isaka, T. (2020). Work volume is an important variable in determining the degree of inhibitory control improvements following resistance exercise. *Physiological Reports*, 8(15), e14527.

https://doi.org/10.14814/phy2.14527

Zimmer, P., Stritt, C., Bloch, W., Schmidt, F.-P., Hübner, S. T., Binnebößel, S., Schenk, A., & Oberste, M. (2016). The effects of different aerobic exercise intensities on serum serotonin concentrations and their association with Stroop task performance: A randomized controlled trial. *European Journal of Applied Physiology*, 116(10), 2025–2034. https://doi.org/10.1007/s00421-016-3456-1