bluuebunny/crossref_metadata_2025 huggingface dataset:
Cardiovascular reactivity and adaptation to recurrent psychological stress: Effects of prior task exposure
Authors: Kelsey Robert M. , Blascovich Jim , Tomaka Joe , Leitten Christopher L. , Schneider Tamera R. , Wiens Stefan
Published: December 2004

The effects of prior task exposure on cardiovascular reactivity to stress were examined in two experiments by randomly assigning participants to repeated exposure groups that performed mental arithmetic pretest and test tasks versus delayed exposure groups that performed only the test task after prolonged rest. Impedance cardiographic and blood pressure measures were recorded continuously from 60 undergraduate men in Experiment 1 and 112 undergraduate men and women in Experiment 2. Task repetition attenuated cardiovascular reactivity and improved task performance in repeated exposure groups (p < .001), suggesting an integrated process of behavioral adaptation. During the test task, delayed exposure groups showed greater cardiac reactivity (p < .01), but not vascular reactivity, than repeated exposure groups. Thus, cardiac reactivity varied as a specific function of prior task exposure, whereas vascular reactivity varied as a general function of time.
Two cognitive systems simultaneously prepared for opposite events
Authors: Ritter Walter , Sussman Elyse , Deacon Diana , Cowan Nelson , Vaughan Herbert G.
Published: December 2004

Event‐related potentials (ERPs) were recorded during a go/no‐go reaction time (RT) task in which subjects responded to rare target tones and withheld response to frequent tones. In a predictable condition, a rare visual stimulus signalled the impending occurrence of a rare tone, whereas a frequent visual stimulus signalled that a frequent tone would be presented. The rare visual stimuli elicited P3, associated with violations of expectations, whereas the rare tones, being predictable, did not. The rare tones elicited the mismatch negativity (MMN), a component associated with preattentive deviance detection, despite the fact that they were expected. RT was faster in the predictable condition than in another condition in which the tones were not predictable. The P3 and RT data indicate, respectively, that subjects anticipated and were ready to respond to the target tones. The MMN result indicates that immediately before target tones, the preattentive system underlying the MMN was set for frequent tones, being unaffected by the information available to the higher order system. Thus, the higher order cognitive system associated with P3 and the lower order cognitive system associated with the MMN were prepared simultaneously for opposite events.
Mixed‐effects models in psychophysiology
Authors: Bagiella Emilia , Sloan Richard P. , Heitjan Daniel F.
Published: December 2004

The current methodological policy in Psychophysiology stipulates that repeated‐measures designs be analyzed using either multivariate analysis of variance (ANOVA) or repeated‐measures ANOVA with the Greenhouse–Geisser or Huynh–Feldt correction. Both techniques lead to appropriate type I error probabilities under general assumptions about the variance‐covariance matrix of the data. This report introduces mixed‐effects models as an alternative procedure for the analysis of repeated‐measures data in Psychophysiology. Mixed‐effects models have many advantages over the traditional methods: They handle missing data more effectively and are more efficient, parsimonious, and flexible. We described mixed‐effects modeling and illustrated its applicability with a simple example.
Effects of fragrance on female sexual arousal and mood across the menstrual cycle
Authors: Graham Cynthia A. , Janssen Erick , Sanders Stephanie A.
Published: December 2004

The effects of fragrance on sexual response in women were investigated using subjective and physiological measures of sexual arousal and of mood. Responses were obtained from female participants in three different fragrance conditions (female fragrance, male fragrance, and a “blank” or neutral substance), as they viewed erotic and sexually neutral films, and fantasized about sexual situations. Each woman was tested twice: during the midfollicular and periovulatory phases of her menstrual cycle. Menstrual cycle phase effects were apparent; self‐report data indicated greater sexual arousal and more positive mood during the periovulatory than during the follicular phase. Results demonstrated a positive effect of the male fragrance on genital arousal during erotic fantasy, but this finding was apparent only during the follicular phase testing session. This effect did not appear to be mediated by any effects of fragrance on mood.
EOG correction: Which regression should we use?
Authors: Croft Rodney J. , Barry Robert J.
Published: December 2004

Electrooculogram (EOG) correction is used to remove eye‐movement‐related contamination from electroencephalograms (EEG). Correction is reliant on the regression procedure, although when multiple EOG channels are used in the correction, the appropriate type of regression to use is not known. In the present study, we aimed to resolve this matter. Computer simulations were used to compare the simultaneous, multiple‐stage, and single‐channel regression methods of correction. EOG propagation was modeled on prior findings, under conditions of varying vertical and horizontal EOG (VEOG/HEOG) correlation. The dependent variable was the correlation between the uncontaminated and the corrected EEG. The simultaneous regression procedure gave the best correction, with its advantage increasing as a function of VEOG/HEOG correlation. It is recommended that the simultaneous regression procedure be used for EOG correction of the EEG.
Error processing and the rostral anterior cingulate: An event‐related fMRI study
Authors: Kiehl Kent A. , Liddle Peter F. , Hopfinger Joseph B.
Published: December 2004

The anterior cingulate is believed to play a crucial role in the regulation of thought and action. Recent evidence suggests that the anterior cingulate may play a role in the detection of inappropriate responses. We used event‐related functional magnetic resonance imaging techniques to examine the neural responses to appropriate (correct rejects and correct hits) and inappropriate (errors of commission) behavioral responses during a go/no‐go task. Analyses of the inappropriate responses revealed extensive activation in the rostral anterior cingulate cortex and in the left lateral frontal cortex. These areas were not activated for correctly classified trials (correct rejects and correct hits). These data suggest that the rostral anterior cingulate and left lateral frontal cortex are integral components of the brain's error checking system.
Visuospatial attention and motor reaction in children: An electrophysiological study of the “Posner” paradigm
Authors: Perchet Caroline , García‐Larrea Luis
Published: December 2004

To assess the processing stages involved in attention shifting and response selection tasks in children, we recorded event‐related potentials (ERPs) and performance measures during a variant of the Posner paradigm. Subjects responded to visual targets, either preceded by a spatial cue (valid = same side; invalid = opposite side) or presented uncued. Valid targets evoked high‐amplitude P1 responses, single‐peaked P3s, and the shortest reaction times (RTs). Invalidly cued stimuli evoked delayed RTs, resulting in part from incorrectly oriented attention (decreased P1) leading to delayed target processing (belated N2‐P3). Invalid targets also evoked a positive slow wave attributed to prolonged response selection due to cue/target incompatibility. Uncued stimuli elicited the longest RTs, unexplained by deficits in target detection or response selection, which likely resulted from a deficit in motor preparation due to the lack of warning signal. This method may be applied in clinical settings to disentangle selective processing deficits in target detection, response selection, or motor preparation stages.
Cardiovascular and electrodermal responses to support and provocation: Interpersonal methods in the study of psychophysiological reactivity
Authors: Gallo Linda C. , Smith Timothy W. , Kircher John C.
Published: December 2004

This study examined the joint and independent effects of experimentally manipulated social contexts and individual differences in hostility and perceived social support on physiological responses to a social stressor, while illustrating the use of the interpersonal circumplex for integrative social psychophysiological research. Undergraduate women completed a speech task in a supportive, neutral, or provoking context and completed measures of hostility and perceived social support. The provoking context evoked the largest blood pressure and heart rate (HR) responses, followed by the neutral and the supportive context. Social context also influenced HR and electrodermal reactivity during task preparation. Hostility elicited higher systolic blood pressure (SBP) reactivity during preparation, speech, and recovery. Perceived social support interacted with context to affect SBP and HR during speech and preparation. The roles of interpersonal characteristics and contexts in the physiological stress response and the utility of interpersonal methods in studying these associations are discussed.
Event‐related potentials elicited during a context‐free homograph task in normal versus schizophrenic subjects
Authors: Salisbury Dean F. , O'Donnell Brian F. , McCarley Robert W. , Nestor Paul G. , Shenton Martha E.
Published: December 2004

Thought disorder in schizophrenia may involve abnormal semantic activation or faulty working memory maintenance. Event‐related potentials (ERPs) were recorded while sentences reading “THE NOUN WAS ADJECTIVE/VERB” were presented to 34 schizophrenic and 34 control subjects. Some nouns were homographs with dominant and subordinate meanings. Their sentence ending presented information crucial for interpretation (e.g., The bank was [closed, steep]). Greatest N400 activity to subordinate homograph‐meaning sentence endings in schizophrenia would reflect a semantic bias to strong associates. N400 to all endings would reflect faulty verbal working memory maintenance. Schizophrenic subjects showed N400 activity to all endings, suggesting problems in contextual maintenance independent of content, but slightly greater N400 activity to subordinate endings that correlated with the severity of psychosis. Future research should help determine whether a semantic activation bias in schizophrenia toward strong associates is reflected in ERP activity or whether this effect is overshadowed by faulty verbal working memory maintenance of context.
Image motion and context: A between‐ and within‐subjects comparison
Authors: Simons Robert F. , Detenber Benjamin H. , Reiss Jason E. , Shults Christopher W.
Published: December 2004

In two previous experiments, we studied how stimulus motion affects both the self‐report of emotion experience and the physiological sequelae of emotion. In both studies, image motion intensified emotional responding, and the effect of motion was relatively specific to the arousal dimension of the emotion; there was little evidence that image motion altered the valence of the image. Moving images also appeared to sustain the attention of the participants for a longer period of time than did the still images. In these two experiments, however, image motion was manipulated within participants. In the present experiment, we used a between‐subjects manipulation of image motion and found a nearly identical pattern of results. These data indicate that motion inherently increments the arousal value of an image and that this increment is not dependent on the context in which motion is introduced.
Focused attention in anhedonia: A P3 study
Authors: Dubal Stephanie , Pierson Annick , Jouvent Roland
Published: December 2004

Attentional and information processing impairments have been evidenced in nonclinical anhedonic subjects. However, the extent of attentional deficit has not been determined. We studied focused attention, the ability to reject irrelevant or distracting messages, in anhedonic nonclinical subjects. The event‐related potentials and behavioral performances of anhedonic subjects were compared with those of control subjects during the Eriksen focused attention task (C.W. Eriksen & B.A. Eriksen, 1974); the task combined one compatible and one incompatible condition, the latter causing an interference. Anhedonic subjects exhibited a smaller P300 and slower reaction times than control subjects. Varying task conditions had different effects on anhedonic subjects and controls, suggesting that anhedonic subjects may have developed a conservative response strategy. In view of previous works, these results suggest that attentional impairment is not ascribed to specific processes, but may involve a more global deficit, that is, a resource allocation deficit.
Electrodermal activity and temperament in preschool children
Authors: Fowles Don C. , Kochanska Grazyna , Murray Kathleen
Published: December 2004

This study had two objectives: To examine poorly understood patterns of young children's electrodermal reactivity and to test the hypothesis that this reactivity reflects individual differences in the behavioral inhibition system (BIS). We recorded skin conductance responses (SCRs) from 92 4‐year‐old children during a laboratory session that encompassed physiological and psychological stimuli. Physiological stimuli (breaths), moderately loud to loud sounds (expected and unexpected) and, to a lesser extent, stimuli with psychological significance elicited clear SCRs. Induction of psychological conflict and exposure to emotional film clips for the most part did not elicit increases in skin conductance (SC). Children's temperament dimensions of fearfulness and effortful (or inhibitory) control—two components of the BIS—were assessed using robust observational batteries at age 2 and 4 years. The theoretically expected correlations between overall SC lability (reflecting SC levels) and both dimensions of temperament were significant, albeit modest and limited to the contemporaneous measures at age 4.
Temperament as a moderator of pathways to conscience in children: The contribution of electrodermal activity
Authors: Fowles Don C. , Kochanska Grazyna
Published: December 2004

A longitudinal study (G. K. Kochanska, 1997) showed that temperamental fearfulness, assessed at toddler age via observational data and maternal ratings, moderated pathways to internalized conscience at age 4. For fearful children, maternal gentle discipline deemphasizing power predicted conscience development; for fearless children, attachment security predicted conscience development. Electrodermal reactivity assessed at age 4 on the same children was used as a physiological reflection of fearful temperament and was substituted for the earlier fearfulness measure to test the theoretical model. As expected, for electrodermally reactive children, maternal gentle discipline predicted conscience, whereas for nonreactive children, attachment security predicted conscience. The findings support the notions of (a) electrodermal reactivity at an early age as a correlate of temperament, (b) temperament as a moderator of socialization in early moral development, and (c) lovelessness in psychopathic individuals as an index of the failure of the alternative pathway (via attachment) to conscience in fearless children.
Time adaptive denoising of single trial event‐ related potentials in the wavelet domain
Authors: Effern Arndt , Lehnertz Klaus , Grunwald Thomas , Fernández Guillén , David Peter , Elger Christian E.
Published: December 2004

We present a new wavelet‐based method for single trial analysis of transient and time variant event‐related potentials (ERPs). Expecting more accurate filter settings than achieved by other techniques (low‐pass filter, a posteriori Wiener filter, time invariant wavelet filter), ERPs were initially balanced in time. By simulation, better filter performance could be established for test signals contaminated with either white noise or isospectral noise. To provide an example of real application, the method was applied to limbic P300 potentials (MTL‐P300). As a result, variance of single trial MTL‐P300s decreased, without restricting the corresponding mean. The proposed method can be regarded as an alternative for single‐trial ERP analysis.
Saccade initiation and accuracy in gaze shifts are affected by visual stimulus significance
Authors: Wang Lin , Stern John A.
Published: December 2004

The effect of visual stimulus significance on saccade latency and accuracy in gaze shifts was investigated. Stimulus significance refers to the temporal proximity of an imperative stimulus. It was hypothesized that stimulus significance serves as a cue that influences the observer's expectancy for a forthcoming event. Twenty‐one undergraduate students participated in two experiments involving monitoring of visual events. Stimuli were a sequence of 1,000 single‐digit integers presented one at a time at 9° of visual angle to the left or right of a fixation point in random order. The subject was required to make a manual response after the presentation of a sequence of two odd integers. The probability of the subsequent integer being odd, a “target,” after the presentation of an odd integer was 0.75. The integer after a target was always an even integer. When stimulus location was unpredictable (Experiment 1), latency of visually guided saccades to the target was shorter (p < .01) than to the nontarget stimuli. Under the condition of predictable stimulus location (Experiment 2), anticipatory saccades to the target occurred earlier (p < .01), more frequently (p < .01), and more accurately (p < .05). Our results suggest that both timing and accuracy of gaze shift are affected by the observer's expectation of future events.
Regional brain activation as a biological marker of affective responsivity to acute exercise: Influence of fitness
Authors: Petruzzello Steven J. , Hall Eric E. , Ekkekakis Panteleimon
Published: December 2004

Previous research has shown that regional brain activation, assessed via frontal electroencephalographic (EEG) asymmetry, predicts affective responsivity to aerobic exercise. To replicate and extend this work, in the present study we examined whether resting brain activation was associated with affective responses to an acute bout of aerobic exercise and the extent to which aerobic fitness mediated this relationship. Participants (high‐fit, n= 22; low/moderate‐fit, n= 45) ran on a treadmill for 30 min at 75% VO2max. EEG and affect were assessed pre‐ and 0‐, 10‐, 20‐, and 30‐min postexercise. Resting EEG asymmetry predicted positive affect (as measured by the energetic arousal subscale of the Activation Deactivation Adjective Check List) postexercise. Furthermore, resting frontal EEG asymmetry predicted affect only in the high‐fit group, suggesting the effect might be mediated by some factor related to fitness. It was also shown that subjects with relatively greater left frontal activation had significantly more energy (i.e., activated pleasant affect) following exercise than subjects with relatively greater right frontal activation. In conclusion, aerobic fitness influenced the relationship between resting frontal asymmetry and exercise‐related affective responsivity.
An early electrophysiological sign of semantic processing in basal extrastriate areas
Authors: Martín‐Loeches Manuel , Hinojosa José A. , Gómez‐Jarabo Gregorio , Rubia Francisco J.
Published: December 2004

Recognition potential (RP), a recently discovered electrophysiological response of the brain, is sensitive to semantic aspects of stimuli. Given its peak values (about 250 ms), RP may be a good candidate for the study of semantic processing during its occurrence. However, its topography and neural generators are largely unknown. To improve this state of affairs, high‐resolution electroencephalography and brain electrical source analysis were carried out. Results suggest a possible origin of RP in the lingual gyrus, hence reflecting the activity of the basal extrastriate areas. RP therefore appears to be a highly valuable tool in the study of those regions considered to be the “third language areas” (in addition to Broca's and Wernicke's areas), whose precise role in language processing is still largely unknown. Another important finding was that RP amplitude in the left hemisphere differed as a function of the semantic category of the stimuli, providing evidence for the sensitivity of this component to semantic categorization. A tentative proposal is made with regard to the role of the basal extrastriate areas.
Saccadic hypometria in drug‐naïve and drug‐treated schizophrenic patients: A working memory deficit?
Authors: Hutton S.B. , Cuthbert I. , Crawford T.J. , Kennard C. , Barnes T.R.E. , Joyce E.M.
Published: December 2004

In certain conditions patients with schizophrenia make markedly smaller (hypometric) saccades than controls. This hypometria has been thought to reflect dopaminergic blockade as a result of antipsychotic medication. We tested this hypothesis by comparing the performance of an antipsychotic‐naïve group and an antipsychotic‐treated group of first‐episode schizophrenic patients on a predictive saccade paradigm. We explored the possibility that hypometria reflects a spatial working memory deficit by correlating performance on neuropsychological tests of mnemonic function with saccadic accuracy. Both the drug‐naïve and treated schizophrenic patients made hypometric saccades when compared with a group of matched controls. Primary saccade amplitude also correlated significantly with performance on some of the neuropsychological tests. These results are discussed in terms of the roles of cortical dopamine and working memory deficits in schizophrenic patients.
Missed prime words within the attentional blink evoke an N400 semantic priming effect
Authors: Rolke Bettina , Heil Martin , Streb Judith , Hennighausen Erwin
Published: December 2004

When subjects identified a target among distractors in a rapid serial visual presentation task, the detection of a subsequent target is impaired (attentional blink). By measuring event‐related potentials (ERPs) we investigated if the processing of an unidentified prime word elicits the N400 semantic priming effect.

Subjects (N= 12) had to identify three target words among distractors in a rapid serial visual presentation task. We varied the association strength between a prime (second target) and a probe (third target). The detection of the prime was impaired. Missed primes did not elicit a P300, indicating that they were not explicitly recognized. Despite this difference between recognized and missed primes, the N400 effect was present in both cases. This result suggests that automatic spread of activation (ASA) can be evoked by missed primes within the attentional blink. It furthermore demonstrates that ASA is sufficient to evoke the N400 effect.
Electroencephalogram differences in two subtypes of Attention‐Deficit/Hyperactivity Disorder
Authors: Clarke Adam R. , Barry Robert J. , McCarthy Rory , Selikowitz Mark
Published: December 2004

This study investigated EEG differences between children with two subtypes of Attention‐Deficit/Hyperactivity Disorder (ADHD) and normal control subjects. EEG was recorded during an eyes‐closed resting condition and Fourier transformed to provide absolute and relative power estimates for the delta, theta, alpha, and beta bands, and the mean frequency for each band was calculated. Ratio coefficients were also calculated between frequency bands. Mean group differences were found in the theta, alpha, and beta bands between all three groups. Similarly, differences were found between all three groups for the theta/alpha and theta/beta ratios and for the mean frequency of the total EEG. These results support a model of ADHD resulting from a developmental deviation rather than a maturational lag in the central nervous system. Differences between the clinical groups in frontal activity suggest that different neuroanatomical systems are involved in the different subtypes of ADHD.
Brain mapping of bilateral visual interactions in children
Authors: Steger Juerg , Imhof Katrin , Denoth Jachen , Pascual‐MarquI Roberto Domingo , Steinhausen Hans‐Christoph , Brandeis Daniel
Published: December 2004

Interhemispheric interactions were studied with functional brain mapping of visual processing. Children performed a reaction time task with uni‐ and bilateral targets and nontargets. The visual evoked potential (VEP) was segmented into P1a, P1b, and N1 microstates using map rather than channel features. Map latencies, amplitudes and sources were tested for bilateral interactions. Bilateral targets yielded shorter VEP map latencies but later response onsets than unilateral ones. Source analyses of the unilateral VEPs indicated a transition from contra‐ (P1a) to ipsilateral (P1b) visual cortex activation (interhemispheric transfer). Bilateral VEPs were smaller than the summed unilateral VEPs in all microstates, indicating that interhemispheric interactions both precede and follow interhemispheric transfer. Brain mapping of uni‐ and bilateral VEPs in children thus revealed several distinct forms of interhemispheric interactions in the same, early time range.
P3b reflects maltreated children's reactions to facial displays of emotion
Authors: Pollak Seth D. , Klorman Rafael , Thatcher Joan E. , Cicchetti Dante
Published: December 2004

Processing of emotion information by maltreated and control children was assessed with event‐related brain potentials (ERPs). Maltreated children, for whom negative facial displays may be especially salient, and demographically comparable peers were tested to increase knowledge of differential processing of emotion information. ERPs were measured while children responded to pictures depicting facial displays of anger, fear, and happiness. Maltreated children showed larger P3b amplitude when angry faces appeared as targets than did control children; the two groups did not differ when targets were either happy or fearful facial expressions or for nontargets of any emotional content. These results indicate that aberrant emotional experiences associated with maltreatment may alter the allocation of attention and sensitivity that children develop to process specific emotion information.
ERP correlates of associative learning
Authors: Rose Michael , Verleger Rolf , Wascher Edmund
Published: December 2004

We examined changes of event‐related potentials (ERPs) while participants learned stimulus‐to‐stimulus relations in an S1‐S2 task. The design allowed for separating processes of associative learning from nonspecific effects. Participants had to respond to S2 by a left or right key‐press dependent on S2 identity (letter W or M). Preparation for S2 could be improved by using the associative information given by S1. The S1 was an arrow pointing to the left or right. In combination with its color, arrow direction was informative about location and identity of S2, but participants were not informed about the relevance of color. Arrows in two of the colors were fully predictive for the S2 whereas the third color gave no valid information. This third stimulus controlled for habituation and procedural learning. Six blocks with 200 trials each and all three S1 colors in random order were presented. Behavioral and ERP differences in each block between “learning” and control trials were used to identify processes of associative learning. Several effects of associative learning were identified indicating the involvement of specific stages of information processing: a continuous increase of P3 amplitude evoked by S1 was accompanied by a decrease of P3 evoked by S2. These changes reflected the modifications of stimulus weights for response selection and the strengthened association between the two stimulus complexes in the time course of learning. The related motor preparation benefited from learning too, expressed in a decrease of CNV amplitude and an increase of LRP amplitude. Finally a decrease of N1 amplitude evoked by S2 indicated the reduced need to allocate spatial attention to the S2 location according to the learned meaning of S1.
New ambulatory impedance cardiograph validated against the Minnesota Impedance Cardiograph
Authors: Nakonezny Paul A. , Kowalewski Ray B. , Ernst John M. , Hawkley Louise C. , Lozano David L. , Litvack Daniel A. , Berntson Gary G. , Sollers John J. , Kizakevich Paul , Cacioppo John T. , Lovallo William R.
Published: December 2004

The validity and reliability of a new ambulatory impedance cardiograph (AZCG) was tested against the Minnesota Impedance Cardiograph (ZCG) during rest, orthostasis, and mental stress. Impedance cardiography allows noninvasive assessment of stroke volume, cardiac output, and systolic time intervals. A reliable ambulatory device would allow studies outside the lab. The devices were compared at two sites in healthy subjects. In both studies, the AZCG tracked changes across conditions closely with the ZCG (all Period × Device interactions were nonsignificant). Pearson rs, were .65 to .93, random intraclass correlation coefficients ranged from .80 to .98, indicating high degrees of shared measurement variance, and Cronbach's alpha indicated very good internal reliabilities (.91 to .99). Relative to the ZCG, the new AZCG appears to provide valid and reliable estimates of cardiac function at rest and during behavioral challenges in the lab.
β‐2 adrenergic receptor gene variations and blood pressure under stress in normal twins
Authors: Li Guo‐Hua , Faulhaber Hans‐Dieter , Rosenthal Magda , Schuster Herbert , Jordan Jens , Timmermann Bernd , Hoehe Margret R. , Luft Friedrich C. , Busjahn Andreas
Published: December 2004

We tested the hypothesis that blood pressure (BP) responses to physical and mental stress are associated with polymorphisms in the β‐2 adrenergic receptor (AR) gene. We studied normotensive, young, monozygotic (MZ) and dizygotic (DZ) twins. The subjects underwent automated BP measurements at the brachial and digital arteries and were subjected to mental arithmetic and cold pressor stress. We used allele‐specific PCR to genotype four single nucleotide polymorphisms in the β‐2 AR gene. The most functionally relevant polymorphism in the β‐2 AR gene, Arg16/Gly, was associated with systolic and diastolic BP under resting conditions, during mental arithmetic, and during the cold pressor test, as well as with the increase in diastolic BP during both forms of stress. These findings support a role for the β‐2 AR gene in BP regulation. They also indicate that the β‐2 AR gene influences the level of not only resting but also stress‐related BP.
Task‐dependent changes in frontal brain asymmetry: Effects of incentive cues, outcome expectancies, and motor responses
Authors: Miller Anita , Tomarken Andrew J.
Published: December 2004

The current study was designed to clarify the psychological functions most closely associated with frontal brain asymmetry. Electroencephalography (EEG) was recorded from 60 participants while they performed a delayed reaction time (RT) task that included manipulations of incentive, expectancy, and response. Significant alpha asymmetry effects were reflected in topographic differences across anterior EEG sites. Variations in monetary incentives resulted in parametric changes in anterior frontal alpha asymmetry. Manipulations of outcome expectancies were related to mid‐frontal EEG changes that differed for men and women. Varied response requirements were related to central asymmetry patterns. Taken together, the findings suggest that regionally specific patterns of frontal asymmetry are functionally related to particular aspects of approach–withdrawal tendencies involved in the temporal guidance and regulation of goal‐directed behavior.
Is pre‐attentive processing compromised by prolonged wakefulness? Effects of total sleep deprivation on the mismatch negativity
Authors: Raz Amir , Deouell Leon Y. , Bentin Shlomo
Published: December 2004

We investigated the potential influence of sustained wakefulness on pre‐attentive capacities by recording the mismatch negativity (MMN), an electrophysiological manifestation associated with nonintentional detection of auditory oddball stimuli. The MMN was elicited by pitch deviants presented to both ears via earphones, at the beginning of a total sleep deprivation session (baseline), after 24 hr, and after 36 hr of continuous controlled wakefulness. A conspicuous MMN response was elicited at all three sessions. With time, however, a small yet significant gradual reduction in the MMN amplitude was evident. Whereas previous research suggested that controlled attention‐demanding tasks are hampered by sleep deprivation, the balance of the present results suggests that passive (total) sleep deprivation may also bring about some degradation in the pre‐attentive detection of environmental irregularities and as a consequence may disrupt the reflexive shift of attention induced by such events.
Conditioned inhibition of fear‐potentiated startle and skin conductance in humans
Authors: Grillon Christian , Ameli Rezvan
Published: December 2004

Conditioned inhibition of classical conditioning was investigated with the startle reflex and the skin conductance response (SCR) in humans using a serial presentation of the conditioned inhibitor (X) and of the conditioned stimulus (CS). The unconditioned stimulus (US) was a shock. During conditioning, participants were presented with two different reinforced CS (A, B) and with X preceding A (noted X → A). During X → A, A was not reinforced with the US. During the summation test, B, X → B, and Y → B were presented (Y was a new stimulus that tested the specificity of the inhibitory properties of X). B was not reinforced during the summation test. A, B, X, and Y were lights of different colors. Participants were divided into a low and a high anxious group based on the TPQ (C.R. Cloninger, 1987). In the low anxious group, conditioned startle potentiation and SCR responses to A were inhibited when X preceded A (noted AXA). This differential responding to A and AXA emerged earlier with the SCR than with startle. During the summation test, the inhibitory properties of X did not transfer to B. In the high anxious group, there was only a differential SCR to A and AXA. X did not inhibit startle potentiation to A.
The quest for the EEG reference revisited: A glance from brain asymmetry research
Authors: Hagemann Dirk , Naumann Ewald , Thayer Julian F.
Published: December 2004

Recent findings suggested that the choice of the EEG reference might be a critical issue for the study of anterior asymmetry in the alpha band. The present paper investigates the validity of different reference schemes for the measurement of alpha asymmetry. A 32‐channel resting EEG was recorded with a common vertex reference (Cz), and transformed into computer‐averaged ears (A1 + A2), average reference (AR), and current source density derivations. A correlation analysis of an alpha asymmetry measure between all derivation schemes indicated a poor convergent validity for anterior sites but an excellent convergent validity for posterior sites. Further analyses suggested the presence of substantial alpha activity at the various reference sites (Cz, A1 + A2, AR), which might be similar in magnitude to anterior but smaller than posterior alpha. These findings suggest that the validity of a reference scheme is a function of the signal‐to‐noise ratio of the electrical activities at target and reference sites. The limitations of each reference scheme for the measurement of anterior alpha asymmetry are discussed.
Comparison of hemodynamic responses to social and nonsocial stress: Evaluation of an anger interview
Authors: Prkachin Kenneth M. , Mills David E. , Zwaal Caroline , Husted Janice
Published: December 2004

Hemodynamic responses to an anger interview and cognitive and physical stressors were compared, and the stability of associated hemodynamic reactions examined. Participants experienced control, handgrip, counting, and mental arithmetic tests and an anger interview on two occasions. Systolic and diastolic blood pressure, heart rate, stroke volume, and cardiac output were measured. Total peripheral resistance was also derived. The anger interview produced larger, more sustained changes in blood pressure in both sessions than the other stressors. These changes were largely a consequence of increased peripheral resistance. Consistent with previous findings, handgrip was associated with a resistance‐type reaction whereas arithmetic was associated with a cardiac output‐type reaction. There was low‐to‐modest stability of hemodynamic reactions to the interview. Further research is necessary to optimize its utility in studies of cardiovascular function. Nevertheless, the findings underscore the ability of ecologically relevant stressors to provoke unique configurations of cardiovascular activity.
Cross‐modal warning effects on reflexive and voluntary reactions
Authors: Zeigler Bonnie L. , Graham Frances K. , Hackley Steven A.
Published: December 2004

Previous research has shown that warning signals can speed the onset of the startle‐blink reflex. To relate this phenomenon to warning effects on voluntary reaction time (RT), the latencies of both reflexive and voluntary responses were measured for nine factorial combinations of warning and reflexogenic stimulus modalities. Previous failures to use factorial manipulations of warning (S1) and reaction (S2) stimulus modalities have led to conflicting results in both the reflex and RT literatures. Using psychophysically matched warning signals, we found a facilitation of reflex latency that was nonspecific with regard to S1 and S2 modality. Furthermore, there was no support for the widely held assumption that visual stimuli are inherently less alerting than auditory and cutaneous stimuli. A between‐group comparison showed that simultaneous voluntary reactions do not distort the reflex facilitation effect. These results support the validity of reflex facilitation as a simple model system for studying warning effects on sensorimotor reactions.
Piecewise latent growth curve modeling of systolic blood pressure reactivity and recovery from the cold pressor test
Authors: Llabre Maria M. , Spitzer Susan B. , Saab Patrice G. , Schneiderman Neil
Published: December 2004

Latent growth curve methodology was used to model systolic blood pressure reactivity and recovery from the cold pressor test. A piecewise regression approach permitted the separate but simultaneous modeling of the two components (reactivity and recovery) of the stress process. Data came from a study of 99 participants classified on the basis of gender, ethnicity, and family history of hypertension. Their systolic blood pressure was assessed at rest, during the cold pressor test, and during a task recovery period. A measure of task appraisal and readings from ambulatory blood pressure monitoring during a workday were also examined. The article illustrates a step‐by‐step approach to modeling reactivity and recovery. Results indicated that both reactivity and recovery were associated with subsequent systolic blood pressure at work.
Breast‐feeding and maternal cardiovascular function
Authors: Mezzacappa Elizabeth Sibolboro , Kelsey Robert M. , Myers Michael M. , Katkin Edward S.
Published: December 2004

Two studies examined the effects of breast‐feeding on maternal cardiovascular function. In the first experiment, groups of breast‐feeding and bottle‐feeding women were compared on preejection period (PEP), heart rate (HR), cardiac output (CO), and total peripheral resistance (TPR) recorded for 1‐min periods before and during standard laboratory stressors. Compared with bottle‐feeders, breast‐feeders had higher CO throughout the session, and greater decreases in CO and increases in TPR during cold pressor. In the second experiment, HR and blood pressure (BP) were compared before and after one breast‐feeding and one bottle‐feeding session in a within‐subjects design. Both feeding methods increased BP but decreased HR, and systolic BP was higher for the breast‐feeding than the bottle‐feeding condition. Both studies support the notion that breast‐feeding alters maternal cardiovascular function, possibly through the actions of oxytocin.
A new model of individual differences in hemodynamic profile and blood pressure reactivity
Authors: Gregg M. Elizabeth , Matyas Thomas A. , James Jack E.
Published: December 2004

A quantitative, theory‐driven model of hemodynamics was developed, relating reactivity in blood pressure to orthogonal dimensions of “hemodynamic profile” and “compensation deficit,” which were derived from the (multiplicative) interaction of cardiac output and total peripheral resistance. A Finapres 2300e was used to estimate blood pressure, cardiac output, and total peripheral resistance in 100 healthy men and women during mental arithmetic and cold pressor tasks on two occasions. Results were consistent with model predictions. As predicted, cardiac output and peripheral resistance reactions were curvilinearly related, and blood pressure reactivity was strongly related to compensation deficit (r= .76–.89). Conversely, the orthogonally defined hemodynamic profile remained independent of blood pressure reactivity (r= .11 or less). The data show that the present model overcomes several difficulties and inconsistencies in previous attempts to obtain an independent measure of hemodynamic profile. The new model could help to elucidate sources of cardiovascular pathogenesis not suggested from the study of blood pressure reactivity alone.
The effect of background noise on P300 to suprathreshold stimuli
Authors: Salisbury Dean F. , Desantis Massimo A. , Shenton Martha E. , McCarley Robert W.
Published: December 2004

Both the amplitude and latency of P300 vary with changes in stimulus parameters. Stimuli at intensities or pitch separations near threshold evoke a smaller and later P300. P300 is also affected by extraneous stimulus parameters in tasks where stimulus frequency separation is large and stimuli are well above intensity thresholds. For example, the presence of background white noise when tones are suprathreshold and easily detectable has been reported to increase P300 latency. However, the effects of background masking noise on P300 amplitude and scalp topography have not been reported. Subjects performed an oddball task both in the presence and in the absence of background noise. Performance accuracy was unaffected by background noise. P300 showed latency increases when noise was present, but P300 peak amplitude was unaffected. P300 scalp topography was stable across both conditions. P300 latency is affected by background noise, even when performance is not, but amplitude and amplitude topography remain unaffected.
Memory reactivation or reinstatement and the mismatch negativity
Authors: Ritter Walter , Sussman Elyse , Molholm Sophie , Foxe John J.
Published: December 2004

Previous studies have suggested that the memory underlying the mismatch negativity (MMN) can be deactivated by a period of silence and later reactivated. An alternative is that the memory becomes inapplicable due to a period of silence and subsequently reinstated. Both interpretations rest on the absence of a MMN for a deviant in Position 1 of a train (showing deactivation or inapplicability of the memory) and the presence of a MMN in Position 2 of the train (evidencing reactivation or reinstatement of the memory). In these studies, the standards were fixed across all trains of a given condition. Hence, it is not clear if the MMN elicited in Position 2 requires presentation of multiple trains with identical standards or only a single train. Experiment 1 showed that a single train is sufficient. With data from recent studies, Experiment 2 showed that MMNs in Position 2 of trains are due to reinstatement rather than reactivation of the memory.
Error negativity and response control
Authors: Pailing Patricia E. , Segalowitz Sidney J. , Dywan Jane , Davies Patricia L.
Published: December 2004

Error trials are associated with faster responses than correct trials in simple discrimination tasks suggesting that errors result from impulsive responding. We investigated the relationship between error negativity (Ne/ERN), an event‐related potential associated with error detection, and two behavioral indices of response control: response time (RT) differences between incorrect and correct trials (an index of impulsivity) and percentage of errors. Response‐locked ERPs were collected from 17 young adults during a visual flanker task. Consistent with previous findings, participants were significantly faster on error trials. However, participants who exhibited larger Ne/ERN peak amplitudes had significantly smaller RT differences, suggesting a more controlled response strategy. Furthermore, Ne/ERN latencies were positively associated with percentage of errors. These findings are consistent with the view that the Ne/ERN reflects the activity of a monitoring system that is closely linked to remedial systems responsible for individual differences in response control or impulsive behavior.
A transcranial magnetic stimulation study of information processing in the motor cortex: Relationship between the silent period and the reaction time delay
Authors: Burle Boris , Bonnet Michel , Vidal Franck , Possamaï Camille‐Aime , Hasbroucq Thierry
Published: December 2004

The present study was aimed at deciphering whether the delay in choice reaction time (RT) and the silent period (SP) caused by transcranial magnetic stimulation (TMS) of the motor cortex in the ongoing electromyogram are due to the same physiological mechanism. To this end, the effect of TMS was studied in 6 healthy volunteers performing a between‐hand choice RT task. Specific predictions were derived from a logic inspired from the “postponed stages” hypothesis (Pashler & Johnson, 1989). This logic predicts a correlation between SP duration and RT when the stimulated cortex is involved in the response, and a stronger correlation when the stimulation is delivered later during the RT interval. The effect of TMS on RT was twofold: At early stimulation times, the stimulation shortened the RT and this effect was independent of the involvement of the stimulated motor cortex in the subsequent response. At later stimulation times, TMS had a disruptive effect, provided that the stimulated cortex was involved in the response. When the stimulated cortex was involved in the response, there was a correlation between SP and RT; this correlation was stronger when the stimulation occurred later. In contrast, there was no correlation between these two variables when the stimulated cortex was not involved.
An alternative to Unibase/glycol as an effective nonhydrating electrolyte medium for the measurement of electrodermal activity
Authors: Dormire Sharon L. , Carpenter Janet S.
Published: December 2004

Although Unibase cream has been an effective medium for electrodermal recordings, its production has recently been discontinued. This study compared alternative media to Unibase for effectiveness. Three base creams similar to Unibase were initially compared for in vitro viscosity and effectiveness. Based upon this analysis one cream was eliminated. A volunteer sample of 6 postmenopausal women with hot flashes and 6 young women without flashes was recruited. Media were evaluated for viscosity and effectiveness of skin conductance. Results indicated that one electrolyte media produced readings within the normal range, identified true positive hot flashes, and produced few false negative readings whereas the second produced largely unreadable results with many false negative hot flashes. An appropriate substitute for Unibase as an effective electrolyte medium for measurement of electrodermal activity was identified.