bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparison of Three Quantification Methods for Estimation of Respiratory Sinus Arrhythmia
Authors: Grossman P. , van Beek J. , Wientjes C. 
Published: February 2007

ABSTRACTThe empirical literature has shown that respiratory sinus arrhythmia is a sensitive noninvasive index of parasympathetic cardiac control. Nevertheless there has been no general agreement among investigators as to the most preferable quantification technique for assessing respiratory sinus arrhythmia, although there has been much speculation that specific estimation techniques are more or less reflective of vagal processes and could be more or less contaminated by other influences upon heart period variability unrelated to respiration. This study compared three quantification procedures for estimating respiratory sinus arrhythmia (RSA): (1) a spectral analytic technique, (2) a complex detrending approach removing periodic and aperiodic cardiac variations unrelated to respiration, and (3) a time‐domain, peak‐valley procedure employing inspiratory and expiratory periods as windows for determining range of cardiac‐interval fluctuations associated with respiratory phase. Measures derived from these techniques were intra‐ and interindividually compared using three different samples of male subjects, including students, adult normotensives, and adult hypertensives. All interindividual correlations between measures yielded coefficients above .92 and the mean within‐subject correlation across 42 individuals was .96, thus indicating a marked degree of comparability between measures. Additionally, given that much evidence indicates lawful within‐individual relations between RSA amplitude and respiratory parameters, we employed respiratory period as an external criterion and compared intraindividual correlations between this variable and (2) and (3); results showed that (3) was significantly more highly associated with respiration than was (2), although the mean r's for the two measures did not diverge greatly (.91 vs. 84). Finally, inspection of the data and further regression analyses did not suggest that any of the RSA estimates were differentially contaminated by other components of cardiac variability. Our findings suggest that the three techniques are almost equivalent as indices of cardiac vagal tone and would appear to ease concerns about the inferiority of any of the procedures. Choice of a quantification procedure should therefore be tailored to the specific empirical needs of an investigation. The advantages and disadvantages of each method are discussed.
Mismatch Negativity Outside Strong Attentional Focus: A Commentary on Woldorff et al. (1991)
Authors: Näätänen Risto 
Published: February 2007

ABSTRACTSeveral previous papers have suggested that the mismatch negativity (MMN), an event‐related potential (ERP) component specific to stimulus change after repetition, is fully automatic, that is, not affected by attention. Woldorff, Hackley, and Hillyard (1991), however, report that the MMN elicited by an intensity decrement of a repeating stimulus is considerably attenuated when attention is strongly focused on other stimuli. The present commentary attributes most of this effect to attention effects on ERP components other than the MMN but also admits that some attentional reduction of the MMN component indeed occurred. This attenuation was interpreted by Woldorff et al. as indicating suppression of early sensory processing in unattended channels, but this is contraindicated by some very recent data from the present author's laboratory and elsewhere showing that the MMN to frequency change is not attenuated outside a strong attentional focus. Consequently, an alternative explanation is proposed for Woldorff et al.'s important finding.
The Truth Will Out: Interrogative Polygraphy (“Lie Detection”) With Event‐Related Brain Potentials
Authors: Farwell Lawrence A. , Donchin Emanuel 
Published: February 2007

ABSTRACTThe feasibility of using Event Related Brain Potentials (ERPs) in Interrogative Polygraphy (“Lie Detection”) was tested by examining the effectiveness of the Guilty Knowledge Test designed by Farwell and Donchin (1986, 1988). The subject is assigned an arbitrary task requiring discrimination between experimenter‐designated targets and other, irrelevant stimuli. A group of diagnostic items (“probes”), which to the unwitting are indistinguishable from the irrelevant items, are embedded among the irrelevant. For subjects who possess “guilty knowledge” these probes are distinct from the irrelevants and are likely to elicit a P300, thus revealing their possessing the special knowledge that allows them to differentiate the probes from the irrelevants. We report two experiments in which this paradigm was tested. In Experiment 1, 20 subjects participated in one of two mock espionage scenarios and were tested for their knowledge of both scenarios. All stimuli consisted of short phrases presented for 300 ms each at an interstimulus interval of 1550 ms. A set of items were designated as “targets” and appeared on 17% of the trials. Probes related to the scenarios also appeared on 17% of the trials. The rest of the items were irrelevants. Subjects responded by pressing one switch following targets, and the other following irrelevants (and, of course, probes). ERPs were recorded from Fz, Cz, and Pz. As predicted, targets elicited large P300s in all subjects. Probes associated with a given scenario elicited a P300 in subjects who participated in that scenario. A bootstrapping method was used to assess the quality of the decision for each subject. The algorithm declared the decision indeterminate in 12.5% of the cases. In all other cases a decision was made. There were no false positives and no false negatives: whenever a determination was made it was accurate. The second experiment was virtually identical to the first, with identical results, except that this time 4 subjects were tested, each of which had a minor brush with the law. Subjects were tested to determine whether they possessed information on their own “crimes.” The results were as expected; the Guilty Knowledge Test determined correctly which subject possessed which information. The implications of these data both for the practice of Interrogative Polygraphy and the interpretation of the P300 are discussed.
Orienting, Habituation, and Resource Allocation: An Associative Analysis
Authors: Siddle David A.T. 
Published: February 2007

ABSTRACTThis paper addresses the question of the most appropriate theoretical account of the phenomena of orienting and habituation. Several lines of evidence are reviewed. First, it is argued that the effects of stimulus omission require a comparator theory in which it is asserted that responses to iterated events result from a comparison between predicted and actual stimulus input. Second, the data from studies in which paired stimulus events are employed seem, at least at first sight, to be best explained in terms of a comparator theory in which a key role is ascribed to associative processes. Third, secondary task probe reaction time data indicate that events that elicit orienting also command processing resources, and that habituation involves changes in the manner in which events are processed. Finally, recent data on the effects of intermodality change indicate that electrodermal responses are larger on the change trial than on the first habituation training trial; these results seem problematical for noncomparator theories. However, other data on the context‐specificity of habituation and on the effects of stimulus miscuing cast doubt on the usefulness of an associative analysis as a general account of habituation phenomena. Nevertheless, the weight of evidence seems to indicate that an adequate theory of human habituation must include a comparison process and must acknowledge that orienting and habituation involve a re‐allocation of attentional resources.
Startle and Emotion: Lateral Acoustic Probes and the Bilateral Blink
Authors: Bradley Margaret M. , Cuthbert Brucse N. , LANG Peter J. 
Published: February 2007

ABSTRACTThe affect‐startle effect describes the modulation of the reflexive eyeblink response to a probe startle stimulus as a function of foreground emotional valence. Larger blinks occur during viewing of unpleasant slide foregrounds, relative to positive foregrounds. This effect has been obtained repeatedly using binaural acoustic startle probes. The current study examines this phenomenon for monaural probes administered to the left and right ears in separate blocks. Startle probes were presented during and between exposures to pleasant, neutral, and unpleasant slides, with the ear of presentation counterbalanced across subjects. Left monaural probes produced blink magnitudes that increased linearly from pleasant to unpleasant slide foregrounds, and appeared to be independent of attention or interest. Right monaural probes did not vary with foreground valence. These findings suggest that the startle probe indexes emotional processing that is lateralized in the central nervous system.
Ongoing Pain as a Mental Workload Indexed by P300 Depression: Discrimination of Real and Feigned Pain Conditions
Authors: Rosenfeld J. Peter , Kim Meekyung 
Published: February 2007

ABSTRACTTwo groups of subjects were formed. One, a real pain group, was subjected to aversive pressure on the fingernail surface during pain‐only and pain‐tracking conditions. The second group (feigned pain) was instructed to feign pain during corresponding runs in which fingernail pressure was applied at a just noticeable (not painful) level. Both groups also simultaneously performed an auditory oddball (.8/.2) task during their pain‐only and pain‐tracking conditions, as well as during an initial (baseline‐1) and final (baseline‐2) baseline condition in which only the oddball task was performed. Oddball‐evoked P300 amplitudes were significantly different for the groups during the pain‐tracking and baseline‐2 conditions, with the amplitudes smaller in the real pain groups in both conditions. The pain‐only and pain‐tracking conditions in both groups caused significant P300 reductions in comparison with baseline‐1 values. P300 latencies did not differ as a function of either groups or conditions. 100% of the real pain subjects and 67% of the feigned pain subjects could be correctly classified using P300 amplitude‐derived indices.
The Effects of Channel‐Selective Attention on the Mismatch Negativity Wave Elicited by Deviant Tones
Authors: Woldorff Marty G. , Hackley Steven A. , Hillyard Steven A. 
Published: February 2007

ABSTRACTThe mismatch negativity (MMN) is an event‐related brain potential elicited by infrequent, physically deviant sounds in a sequence of repetitive auditory stimuli. Two dichotic listening experiments that were designed to optimize the selective focusing of attention provided a strong test of Näätänen's proposal that the MMN is unaffected by attention and reflects the operation of a strongly automatic mismatch detection system. In Experiment 1, tones were presented at intervals of 120‐320 ms, and the deviant tones (intensity decrements) in both the attended and unattended ears elicited negative waves consistent in waveshape, latency, and distribution with previously described MMNs. In contrast to previous reports, however, the MMN elicited by the unattended‐channel deviant was markedly reduced (peak amplitude of less than 1 μV) relative to the corresponding negative wave elicited by the attended‐channel deviants (3–4 μV), as well as relative to previously reported MMNs (3–6 μV) elicited by comparable deviations in stimulus intensity. In Experiment 2, which employed interstimulus intervals of 65–205 ms, the unattended‐channel MMN elicited by the deviant fainter tones was barely discernible, whereas the corresponding attended‐channel negativity was again about 3‐4 μV.These findings call into question the assertion that the auditory mismatch detection process and the associated MMN wave are wholly independent of attentional influence. Rather, these data provide evidence that the processing of stimuli in unattended channels can be attenuated or gated at an early sensory level under conditions of highly focused auditory selective attention.
Heart Rate Variability During Attention Phases in Young Infants
Authors: Richards John E. , Casey Betty Jo 
Published: February 2007

ABSTRACTHeart rate variability during visual attention was studied in infants who were tested cross‐sectionally at 14, 20, or 26 weeks of age. They were presented with a recording of a Sesame Street program on a TV screen. After heart rate had decelerated below the prestimulus level and then returned to prestimulus level, a computer‐generated pattern replaced the Sesame Street display. Heart rate variability changed throughout attention. The change consisted of a decrease in variability during attention and a return to prestimulus levels approximately five seconds following attention termination. The heart rate and variability responses are consistent with a model of parasympathetic vagal influence on the heart in which vagal firing is increased during sustained attention and is inhibited during attention termination.
What do Arithmetic Stress Tests Measure? Protocol Variations and Cardiovascular Responses
Authors: Linden Wolfgang 
Published: February 2007

ABSTRACTThree studies tested the effects of the following design/protocol variations in mental arithmetic: 1) Order of task, 2) vocal versus written delivery of responses, 3) effects of different types of superimposed noise distractors, and 4) varying types of mental arithmetic challenges. All studies used the same basic protocol with 20‐min adaptation, 5‐min task, and 3‐min recovery periods; dependent cardiovascular variables were systolic and diastolic blood pressure and heart rate; in Study 2 respiration rate and respiratory amplitude were also assessed.Findings showed that vocal delivery enhanced subjective distress, lowered performance, and enhanced diastolic blood pressure responses. Noise distraction augmented distress but did not affect task performance. Variable noise distraction augmented systolic blood pressure and heart rate responses but only when math equations were presented on a video screen. Autonomic response adaptation was apparent from first to second tasks but not thereafter. The built‐in replications strengthened these findings.
Removal of the Ocular Artifact from the EEG: A Comparison of Time and Frequency Domain Methods with Simulated and Real Data
Authors: Kenemans J. Leon , Molenaar Peter C.M. , Verbaten Marinus N. , Slangen Jef L. 
Published: February 2007

ABSTRACTFrequency‐dependent transfer from EOG to EEG may be insufficiently accounted for by simple time domain regression methods (Gasser, Sroka, & Möcks, 1986; Woestenburg, Verbaten, & Slangen, 1983). In contrast, a multiple‐lag time domain regression analysis, using lagged regression of EEG on EOG, must theoretically account for both frequency dependence and independence.Two data sets were constructed, in which the transfer from EOG to EEG was either frequency‐independent (constant gain) or frequency‐dependent. Subsequently, three different correction methods were applied: 1) a simple regression analysis in the time domain; 2) a multiple‐lag regression analysis in the time domain; and 3) a regression analysis in the frequency domain.The major results were that, for data set 1, the three methods constructed the original EEG equally well. With data set 2, reconstruction of the original EEG was achieved reasonably well with the frequency domain method and the time domain multiple‐lag method, but not with simple time domain regression. These three correction procedures were also applied to real data, consisting of concomitantly recorded EEG and high‐variance EOG series. No appreciable differences in outcome of the three methods were observed, and estimated transfer parameters suggested that these data were marked by weak frequency dependence only, which can be accounted for by simple time domain regression (and also by the other two methods).
Dimensional Analysis of No‐Task Human EEG Using the Grassberger‐Procaccia Method
Authors: Pritchard Walter S. , Duke Dennis W. 
Published: February 2007

ABSTRACTA method developed by Grassberger and Procaccia allows estimation of the dimensional complexity of the state‐space attractor of a time series. Saturation of dimensional‐complexity estimates with increasing values of embedding dimension is considered a strong indication that the time series is governed by deterministic chaos. The present investigation employed the Grassberger‐Procaccia method to estimate EEG dimensional complexity in a multi‐subject, factorial experiment. Twelve subjects were tested under two no‐task conditions (eyes closed and open), with the block of two conditions being repeated four times. EEG was recorded from the nineteen 10‐20 loci. Dimensional complexity declined across Blocks 1‐3 and then leveled off, and was higher in the eyes‐open than in the eyes‐closed condition. Condition also interacted with locus in that the increase in dimensional complexity associated with opening the eyes was greater over occipital loci. Comparison with the results of Fourier analysis indicated that a similar but not identical pattern of effects was obtained for alpha (8‐12 Hz) power. Further, across the entire data set, if alpha power exceeded a value of about 70 μV2, demensional complexity was uniformly low, a finding in concert with previous results indicating that the eyes‐closed, occipital alpha rhythm possibly represents deterministic chaos of relatively low dimension.
Pregnancy Alters Blood Pressure Responses to Psychological and Physical Challenge
Authors: Matthews Karen A. , Rodin Judith 
Published: February 2007

ABSTRACTThe purpose of the study was to evaluate the effect of the substantial changes in female reproductive hormones that occur during normal pregnancy on cardiovascular responses to psychological and physical challenges. Twenty‐one healthy normotensive women performed serial subtraction, mirror image tracing, and isometric handgrip exercise tasks prior to pregnancy and again during the second trimester of pregnancy. A control group of 34 healthy women who did not intend to become pregnant and were nonpregnant were also tested in the same protocol twice, 6–10 months apart. Results showed that the pregnant women exhibited a reduced diastolic blood pressure response to all three tasks, relative to their pre‐pregnancy levels, whereas nonpregnant controls did not change in their diastolic blood pressure response across time. These results are consistent with the hypothesis that elevations in female reproductive hormones diminish blood pressure responses during challenge because of dampened sympathetic nervous system activity.
Increased Salivary Cortisol in Severe Dental Anxiety
Authors: Benjamins Carmen , Asscheman Henk , Schuurs Albert H.B. 
Published: February 2007

ABSTRACTThe aim of the present study was to investigate the feasibility of saliva collection from highly anxious dental patients and to evaluate whether salivary cortisol concentrations could discriminate between 13 highly anxious dental patients and 13 non‐anxious subjects. Whole mixed saliva was sampled by suction after stimulation with citric acid crystals. Salivary free cortisol levels were measured in duplicate by radioimmunoassay. Collection of saliva took 2–5 min and was not experienced as unpleasant. Salivary free cortisol concentrations were significantly elevated if the patients manifested anxiety according to the scores on the Dental Anxiety Scale. The measurement of salivary cortisol may be a convenient method for the assessment of dental anxiety.
Myocardial and Peripheral Vascular Responses to Behavioral Challenges and Their Stability in Black and White Americans
Authors: Saab Patrice G. , Llabre Maria M. , Hurwitz Barry E. , Frame Charles A. , Reineke Lori J. , Fins Ana I. , McCalla Judith , Cieply Larry K. , Schneiderman Neil 
Published: February 2007

ABSTRACTThe purpose of this study was to assess the short term stability of myocardial and peripheral vascular responses to behavioral challenges, and to compare the response patterns of Black and White men. Blood presure and heart rate, as well as stroke volume, cardiac output, total peripheral resistance, and systolic time interval measures derived from the impedance cardiogram were obtanined in 12 Black and 12 White men. These measures were taken prior to and during an evaluative speech stressor, a mirror star tracing task, and a forehead cold pressor test presented during two laboratory sessions scheduled two weeks apart. In general, total peripheral resistance and impedance‐derived baseline measures showed acceptable reproducibility (G>.85). With a few exceptions, adequate reliability was also demonstrated for change (delta) scores. All tasks raised blood pressure responses above resting levels. Blacks demonstrated significantly greater increases in total peripheral resistance responses across tasks. Whites but not Blacks also revealed increases above baseline in cardiac output and contractility as estimated by the Healther Index. These findings are consistent with the view that Blacks show greater vascular responsiveness than Whites across a variety of tasks, but reveal less myocardial responsiveness.
Event Related Potentials and EEG Components in a Semantic Memory Search Task
Authors: Mecklinger Axel , Kramer Arthur F. , Strayer David L. 
Published: February 2007

ABSTRACTThis study examined the effects of memory search and related processes on both time and frequency domain components of electroencephalographic activity. More specifically, we were interested in the relationship between EEG and event‐related potential (ERP) components as a function of memory load and response type. Subjects performed a semantic memory search task in which they matched word probes to category labels. Consisten with previous studies, reaction time increased and accuracy decreased with increasing memory loads. A negative component of the ERP (N400) was found to reflect semantic mismatch: N400s were larger for the nontargets than for the targets. Two ERP components were found to be reciprocally related to memory load. P300 decreased and Negative Slow Wave increased in amplitude with increases in the size of the memory set. These two ERP components were reflected by different components in a Principal Components Analysis. The power in the theta band (5–7 Hz) also increased as a function of memory load and appears to be functionally and topographically related to the Negative Slow Wave in the ERP. It is argued that both measures are jointly determined and reflect the difficulty of the conceptual operations during memory search.