bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Age and Sex on the Endogenous Brain Potential Components During Two Continuous Performance Tasks
Authors: Friedman David , Boltri John , Vaughan Herbert , Erlenmeyer‐Kimling L.
Published: February 2007

Event‐related potentials (ERPs) were recorded during two versions of the continuous performance test (CPT) from 74 adolescents grouped into 6 yearly age intervals (12–17) in a cross‐sectional study of the effects of age and sex on the cognitive ERPs. The two CPTs differed in their processing complexity, with Task B requiring an additional stage of information processing not needed for performance on Task A. The effects of Stimulus (Signal/Non‐Signal), Task (A/B), and Electrode Location (FZ/CZ/PZ/OZ) were highly similar to those reported by Friedman, Vaughan, and Erlen‐meyer‐Kimling (1981) for a subsample (N = 30) of this group of subjects. New findings were highlighted by the analyses of the effects of age and sex on the six electrophysiological events (N150, P240, P350, P450, P550, Slow Wave) recorded during these CPTs. Principal Components Analysis (PCA) was used in an attempt to reduce overlap among components, with the factor scores compared to the baseline to peak measures. Modest age effects were found for P450 (classical P300), with the pattern of findings suggestive of differences in processing strategies between the older and younger adolescents. PCA performed on the first 408 ms of the ERP epoch yielded a component corresponding to an early‐onset endogenous negativity which showed a decrease in amplitude with increments in chronological age. Effects of sex were found for P550 and Slow Wave. While the pattern of results may indicate differences between males and females in cognitive processing mode, the design of these CPTs does not allow a functional association between these components and the modes of processing that have been reported to differentiate males and females. The data highlight the importance of including age and sex as variables whenever investigations of cognitive ERPs are undertaken.
Caffeine Affects Cardiovascular Responses to Stress
Authors: Lane James D. , Williams Redford B.
Published: February 2007

The effects of caffeine on cardiovascular activity at rest and during psychological stress were examined in 33 healthy male college students who did not normally ingest caffeinated products. Caffeine (250 mg) and placebo were administered double‐blind in separate sessions. Heart rate, blood pressure, and forearm blood flow and vascular resistance were assessed at rest and during the stressful, competitive performance of a mental arithmetic task. Comparisons of caffeine and placebo sessions revealed that caffeine elevated resting blood pressure 4–6 mmHg, an effect which added to the elevation produced by stress. Caffeine did not affect resting forearm blood flow but potentiated the forearm blood flow response to stress and led to higher levels of flow during stress. No caffeine effects appeared in heart rate or in task performance. Family history of hypertension and Type A behavior were examined as potential modulating factors of caffeine effects but results were generally negative. These results suggest possible mechanisms through which caffeine could enhance the pathogenic effects of stress on the cardiovascular system.
Cardiovascular Responsivity, Type A Behavior, and Parental History of Heart Disease in Young Women
Authors: Lawler Kathleen A. , Schmied Lori A.
Published: February 2007

The purpose of this study was to examine the physiological responsiveness of Type A and Type B women during interpersonal and individual, competitive stressors. Extreme groups of Types A and B college‐age women were monitored on heart rate and blood pressure while they engaged in an oral history quiz and the Stroop color/word test. Subjects were also subdivided by presence or absence of family history of coronary heart disease. Types A and B women did not differ on blood pressure levels or reactivity; Type A women did show a trend toward a greater increase in heart rate to the color/word task. Women with a positive family history had higher levels of systolic and a trend toward higher levels of diastolic blood pressure. There were no significant interactions of Type A/B with family history. Our conclusion is that Type A behavior is only very weakly, if at all, associated with physiological responsivity in young adult women.
Steady State Evoked Responses: Correlations with Human Cognition
Authors: Wilson Glenn F. , O'Donnell Robert D.
Published: February 2007

This paper describes data which for the first time show correlations between the visual steady state evoked response (SSER) and human cognitive activity. Individual subjects exhibit characteristic evoked potential phase relationships to flicker stimuli, and these were found to be related to the individual's speed of response in a memory scanning task. In addition, evoked response phase lags to different flicker frequencies were related to the component processes involved in the task. The brain's response to high frequency flicker is related to the sensory input portion of a memory scanning task while the response to medium frequency flicker is related to the memory look‐up aspects of this task.
Heart Rate Reactivity and Type A Behavior as Modifiers of Physiological Response to Active and Passive Coping
Authors: Lovallo William R. , Pincomb Gwendolyn A. , Wilson Michael F.
Published: February 2007

We examined the long term predictivity of heart rate reactivity (HRR) and its relation to cardiovascular and biochemical activity during rest and during tasks requiring active and passive coping. HRR was determined in 28 young men by measuring peak heart rate change to cold pressor one year after performing tasks eliciting active and passive coping. Heart rate change to cold pressor was significantly correlated with change to active coping (r= .65, p<.01) and to passive coping (r= .53, p<.01). Responses to the tasks were equivalent for Type A and B subjects. On the other hand, high HRRs were significantly more reactive than low HRRs with the effect being most apparent during active coping. HRR appeared to be a trait stable over one year which predicted enhanced cardiac, neuroendocrine, and neuromuscular response.
A Dose‐Response Study of Sleep Loss and Spontaneous Sleep Termination
Authors: ÅKerstedt Torbjörn , Gillberg Mats
Published: February 2007

Recent concepts of sleep/wake regulation have emphasized circadian influences and largely disregarded homeostatic ones. The present experiment was designed to study sleep loss homeostasis while minimizing confounding circadian influences. Eight male subjects participated in the study. Night sleep was curtailed across four conditions to yield 0, 2, 4, or 8 hrs of sleep. The effects were studied on subsequent day sleep begun at 1100h and spontaneously terminated. Total sleep time (TST), Stage 2 (S2), and Stages 3+4 (SWS) showed very strong dose‐dependent increases with increasing loss. REM sleep did not respond. After maximum sleep loss TST and S2 doubled whereas SWS increased fivefold. Sleep did not terminate until the prior loss of SWS had been recovered. The total SWS recovery approximately matched the loss. TST, S2, and REM failed to recover more than limited amounts of the loss. The results show that homeostatic influences on sleep may be much larger than usually acknowledged and that SWS closely, although not perfectly, reflects the “active component’ of sleep homeostasis.
The Alerting Effects of Naps in Sleep‐Deprived Subjects
Authors: Lumley Mark , Roehrs Timothy , Zorick Frank , Lamphere James , Roth Thomas
Published: February 2007

The effect of napping for varying durations after one night of sleep deprivation was examined. Sleep latency tests were used to determine levels of sleepiness/alertness at 2, 4, 6, and 8 hrs following a morning nap of 0, 15, 30, 60, or 120 min duration. Ten normal‐sleeping, young adult volunteers spent two consecutive days and the intervening night in the sleep laboratory on each of five weeks. Baseline sleep latencies were recorded the first day, sleep was deprived that night, a nap was taken at 0900 hrs, and sleep latencies were again recorded on the second day. The naps had differential alerting effects related to their duration, but none of the naps returned mean sleep latency for the 8 hrs to its basal levels. Alertness increased with nap duration, reaching its highest level with a 60‐min nap; the 120‐min nap was no more alerting than the 60‐min nap. During the second hour of the 120‐min nap, sleep became more fragmented with more shifts to stage 1 sleep or wake. Increased alertness was not strongly related to the sleep stage composition of the naps, the best predictor being minutes of slow wave sleep. Increased alertness was not detected until the second latency test 4 hrs after napping.
Behavioral Control Over Sleeping Respiration in Normals for Ten Consecutive Nights
Authors: Badia Pietro , Harsh John , Balkin Thomas
Published: February 2007

Behavioral control over sleeping respiration in 5 healthy college students was tested over 10 consecutive nights and 1 additional night 1–2 weeks later. Participants were polygraphically recorded each night and the records scored using standardized criteria. They were informed while awake that tones (.5 s on/off, 4000 Hz) would be presented to them (variable interval schedule, X̄=7.5 min) during nighttime sleep and that their task was to terminate them by taking a deep breath. Behavioral control over respiration was maintained over the 10 nights. Latency to respond gradually increased over the first 5 nights and then leveled out for the remaining 5 nights. On the test night, 1–2 weeks following Night 10, latency to respond was similar to Nights 1 and 2. Percentage of time spent in each sleep stage and the pattern of arousals to tones and responses were similar to earlier reports (more stage 1, less stage 3–4; frequent arousals). It was concluded that behavioral control over sleeping respiration can be obtained and maintained in normal college students over at least 10 nights but a limiting factor may be the increase in response latency.
The Influence of Latency Jitter in Principal Component Analysis of Event‐Related Potentials
Authors: Möcks Joachim
Published: February 2007

Principal component analysis of event‐related potentials is known to be suspect when underlying components have varying latency. In this note it is theoretically shown that approximately an additional component may be assumed, being the time‐derivative of the underlying component. Validity of this approximation is demonstrated in a simulation study.
EOG‐Based Recording and Automated Detection of Sleep Rapid Eye Movements: A Critical Review, and Some Recommendations
Authors: Boukadoum A.M. , Ktonas P.Y.
Published: February 2007

This paper presents a critical discussion of methods used for the recording and the automated detection of sleep rapid eye movements (REMs) via electro‐oculographic (EOG) methodologies. Specifically, the paper elaborates on: 1) various EOG montages for sleep eye movement recording, 2) AC vs. DC coupling for EOG signal amplification, 3) artifact presence and elimination thereof via filtering of the EOG signal, and 4) available EOG‐based automated methods for REM detection. Recommendations for the development of an “optimum’ automatic sleep REM detection system based on EOG recordings are presented as well.
Multiple P3s to Emotional Stimuli and Their Theoretical Significance
Authors: Johnston Victor S. , Miller David R. , Burleson Mary H.
Published: February 2007

Event‐related potentials (ERPs) were recorded to both predictive (consonant‐vowel‐consonant) and feedback (picture) stimuli as subjects learned associations between these stimuli. The consonantvowel‐consonants (CVCs) were selected for lack of emotional content while the pictures (PICs) varied in emotional value (Learning Group; N=20). A second group of subjects was exposed to the same CVC‐PIC stimuli but was required only to count the number of different CVCs and PICs (Counting Group; N=20). A principal components analysis with varimax rotation was performed on ERPs to PICs and revealed multiple late positive components (P3 and P4) and a slow positive wave (SPW). In both groups, the P3 and P4 factors varied with the emotional value of the stimuli. The learning group had a larger SPW than the counting group, and disconfirmed predictions elicited larger P4s than confirmed predictions. For CVC stimuli, only P4 increased as subjects learned CVC‐PIC relationships. From the similar scalp and temporal distributions of P3 and P4, as well as their functional similarity, it was concluded that these two factors reflect the same neural process which is activated by the emotional value of stimuli. One possible function of this process is suggested.
Effect of Noise Distraction during Mental Arithmetic on Phasic Cardiovascular Activity
Authors: Linden Wolfgang
Published: February 2007

The present study investigated the effects of four experimental variations of mental arithmetic on subjective stress, systolic and diastolic blood pressure, and heart rate. The four conditions were: 1) mental arithmetic only, 2) mental arithmetic with steady 90dB(A) white noise distraction, 3) mental arithmetic with steady real‐life noise distraction averaging 90dB(A), and 4) mental arithmetic with varying real‐life noise distraction averaging 90dB(A). Subjects were 63 healthy young adults of both genders. The statistical analyses evaluated gender and conditions as independent variables and initial response magnitude as well as within‐task adaptation of blood pressure and heart rate. Observed differences for the various experimental conditions were remarkably few: 1) more systolic blood pressure adaptation was found during steady real‐life noise distraction than in other conditions; 2) there was a trend toward diastolic blood pressure adaptation for all conditions except the variable real‐life noise; and 3) enhanced heart rate responses were displayed during varying real‐life noise distraction relative to the other conditions. Overall, the findings are held to indicate that blood pressure and heart rate initial reactivity and adaptation are unaffected by noise distraction with the exception of an exaggerated heart rate response in conditions of high stimulus variability.
Sibling Similarities in Cardiovascular Reactivity to Stress
Authors: Ditto Blaine
Published: February 2007

To examine the similarities of nun‐twin sibling pairs in cardiovascular reactivity to stress, in terms of both individual parameters such as heart rate and general cardiovascular reactivity, 36 young adult sibling pairs were recruited. Members of 12 same‐sex male, 12 same‐sex female, and 12 opposite‐sex pairs participated in a 66‐min experimental protocol consisting of alternating stress and relaxation periods. Pour stressors were employed: a challenging conceptual task, mental arithmetic, isometric bund‐grip, and the cold pressor test. Repeated measurements of systolic and diastolic blood pressure (SBP. DBF), heart rate (HR), ear pulse transit time (EPTT), and digital blood volume pulse (DBVP) were obtained. Pair members exhibited significant similarities in resting SBP, DBP, and HR. A number of significant similarities in reactivity to stress were observed. To examine the specificity of familial influences on different aspects of cardiovascular response to stress, a number of canonical and cross‐correlations were computed. The cardiovascular reactions of one sibling were used to predict those of his/her brother or sister. Several of the correlations attained significance. Most interestingly, familial influences on SBP, DBP, and DBVP reactivity to the cold pressor test appear to exhibit some degree of overlap, possibly reflecting more fundamental familial influences on alpha‐adrenergic reactivity. Joint familial influences on behavioral and cardiovascular reactivity to stress are discussed.
A Data‐Based Method for Bivariate Outlier Detection: Application to Automatic Blood Pressure Recording Devices
Authors: Clark L.A. , Denby L. , Pregibon D. , Harshfield G.A. , Pickering T.G. , Blank S. , Laragh J.H.
Published: February 2007

The rapidly increasing use of automatic devices for the measurement of blood pressure has made it increasingly important to identify artifactual readings. This paper describes an objective technique for isolating a small but adjustable percentage of the readings that are likely artifacts. The validity of these readings requires the subjective judgment of the clinician. The proposed methodology substantially reduces the number of readings to be manually examined by not only taking into account the level of systolic and diastolic blood pressure per se, but also the relationship between the two and how they vary according to differential covariate information. The method can be applied to homogeneous populations, or as illustrated in this paper, to heterogeneous populations after adjustment for known or suspected sources of variability. Thus the technique is applicable to protocols which examine blood pressure, or for that matter any two (or more) related variables, during a variety of experimental procedures including psychophysiological reactivity tasks.
Evaluation of a New Ambulatory Blood Pressure Monitor (Accutracker 102): Laboratory Comparisons With Direct Arterial Pressure, Stethoscopic Auscultatory Pressure, and Readings From a Similar Monitor (Spacelabs Model 5200)
Authors: Light Kathleen C. , Obrist Paul A. , Cubeddu Luigi X.
Published: February 2007

Systolic (SBP) and diastolic (DBP) blood pressure levels generated by a new noninvasive ambulatory monitor, the Accutracker 102, were compared in the laboratory with intra‐arterial pressure levels in 12 normotensive men, and with stethoscopic auscultatory determinations in 27 normotensive and hypertensive men and women over a wide range of within‐subject pressure variations. In 11 subjects, its performance was also compared with another ambulatory monitor, the Spacelabs Model 5200. Highly positive correlations with both the intra‐arterial (medianr=+.90 for SBP, +.92 for DBP) and the stethoscopic standards (medianr=+.93 for SBP, +.88 for DBP) were obtained using Accutracker's automatic readings (digital readout), while slightly higher correlations were obtained with hand‐scoring of recorded data. The Spacelabs BP monitor also yielded readings that were highly correlated with stethoscopic readings (medianr=+.83 for SBP, +.77 for DBP), although in 3 of the 11 subjects the Accutracker correlations were substantially higher than the Spacelabs correlations. Despite their generally good tracking of changes in pressure, both ambulatory monitors yielded absolute values in many subjects that differed by 5 mmHg or more from stethoscopic levels. The Accutracker's SBP levels were consistently too high and its DBP levels were occasionally too low, while Spacelabs' SBP and DBP values were too high and too low with equal frequency. However, mean deviation scores for each patient calculated from 5 concurrent ambulatory monitor and stethoscopic readings were shown to yield relatively stable correction factors for use when comparison with clinical standards is desired.
Third Ventricle Enlargement and Reduced Electrodermal Responsiveness
Authors: Cannon Tyrone D. , Fuhrmann Michael , Mednick Sarnoff A. , Machon Ricardo A. , Parnas Josef , Schulsinger Fini
Published: February 2007

Using a subsample of subjects from the Copenhagen schizophrenia high‐risk project, we investigated the relationship between enlargement of the third ventricle and phasic electrodermal activity, as measured by amplitude and frequency of responses to orienting, unconditioned, conditioned, and generalization stimuli. Subjects with enlarged third ventricles evidenced significant overall reductions in amplitude and frequency of response, and significantly lower response levels to orienting, conditioned, and generalization stimuli. These effects were independent of psychiatric diagnosis and enlargement of the lateral cerebral ventricles. Difficulties in interpretation posed by the index of atrophy employed and by the 18‐year time interval between the electrodermal and brain measures are discussed. The results are presented as a preliminary indication of an association between third ventricle enlargement and reduced autonomic nervous system activity.
The Effects of Cognitive and Physical Stress on Cardiovascular Reactivity Among Smokers and Oral Contraceptive Users
Authors: Emmons Karen M. , Weidner Gerdi
Published: February 2007

Blood pressure and heart rate responses to cognitive (mental arithmetic) and physical (cold pressor) stress were monitored in four groups of women: 1) smokers/non oral contraceptive (OC) users, 2) non‐smokers/OC users, 3) smokers/OC users, and 4) non‐smokers/non‐OC users (control). All subjects were reactive to both types of stress. The results suggest that oral contraceptive use among smokers may enhance systolic blood pressure reactivity to cognitive stress when compared to smokers/non‐OC users. Also, OC use among women with a parental history of heart disease was marginally associated with elevated systolic and diastolic blood pressure responses to the cold pressor test. These findings suggest that oral contraceptive use may interact with smoking and parental history of heart disease and warrant further investigation.
Effects of Autonomic Blockade on Heart Rate Responses to Reaction Time and Sustained Handgrip Tasks
Authors: Pollak Michael H. , Obrist Paul A.
Published: February 2007

This study used both beta‐adrenergic and cholinergic pharmacological blockade to investigate differences in autonomic mediation of heart rate responses during reaction time and sustained handgrip tasks. Forty‐five healthy young men received a venous infusion of saline and then performed each task for the first time. Then, each subject received a second infusion consisting of either saline, propranolol hydrochloride, or atropine sulfate, and repeated each task. For each infusion, the 15 subjects in each group were unaware of which of the three substances they were receiving. The results indicate that heart rate increases during the reaction time task were mediated by increased beta‐adrenergic activity, whereas heart rate increases during handgrip were mediated by a combination of increased beta‐adrenergic activity and vagal withdrawal. These results support the hypothesis that neural mechanisms mediating cardiac adjustments during some types of psychological stress differ qualitatively from mechanisms mediating similar‐appearing adjustments during some types of physical exertion.
The Effects of Vigorous Exercise on Anxiety, Heart Rate, and Alpha Activity of Runners and Nonrunners
Authors: Boutcher Stephen H. , Landers Daniel M.
Published: February 2007

State anxiety, heart rate, and alpha activity of male nonrunners and runners (N=30) during a vigorous run and a quiet reading session were examined. Physical activity was performed at 80–85% age‐related maximal exercise heart rate for 20 min; the same subjects participated in a reading condition. Analysis revealed a significant decrease in post‐run state anxiety for the runners compared to the nonrunners. No reduction in state anxiety for either group was found after the reading condition. Runners also significantly reduced their heart rate after the run compared to nonrunners. A significant increase in alpha activity for both runners and nonrunners was found after the run compared to the reading condition. These results suggest that post‐exercise anxiety and heart rate responses were influenced by level of aerobic conditioning. Furthermore, dissimilar anxiety, heart rate, and alpha responses were found after the reading and exercise conditions.
Individual Differences in Heart Rate and Peripheral Vascular Responses to an Extended Aversive Task
Authors: Miller Sydney B. , Ditto Blaine
Published: February 2007

Psychophysiological research on situations requiring active coping has to this point dealt primarily with cardiac responses. Recent studies of vascular responses to such stressors have found conditions in high cardiac reactors that are possible precursors to autoregulatory vasoconstriction. The present study exposed 32 healthy male undergraduates to a one‐hour shock avoidance procedure, with avoidance made contingent on video‐game performance. Subjects also participated in a separate counterbalanced baseline session. The relationships among individual differences in heart rate, forearm blood flow, forearm vascular resistance, and digital blood volume pulse responses at different points in the stress session were examined. Decreases in forearm vascular resistance were observed only among high and medium heart rate reactors. As the session progressed, however, forearm vascular resistance responses of the medium heart rate reactors were sustained whereas those of the high heart rate reactors habituated despite the fact that heart rate and forearm blood flow responses remained elevated. The potential implications of this pattern of results to an autoregulation theory of hypertension development are discussed. Heart rate reactivity was inversely related to performance on the video‐game task but was unrelated to Type A or anxiety.
The Effect of Intermittent Noise on Cardiovascular Functioning During Vigilance Task Performance
Authors: Carter Norman L. , Beh Helen C.
Published: February 2007

This study was designed to investigate the effect of presentations of intermittent noise differing in predictability on cardiovascular functioning during task performance. Under a quiet condition and three conditions of intermittent noise, measures of blood pressure, heart rate (interbeat interval), and heart rate variability (variance, successive difference mean square, and the 0.1 Hz component of sinus arrhythmia) were obtained while subjects were occupied with a 55‐min vigilance task. The results indicated that intermittent noise significantly increased diastolic and mean blood pressure. In addition, 0.1 Hz measures differed between the group working under quiet conditions and the groups working under noise. Although heart rate increased in all groups during the task, it increased significantly more in groups receiving unpredictable noise bursts. For the variables that were significantly affected by the noise presentations there was no evidence of response habituation over the task period. The results are discussed in relation to the effort required to maintain performance levels during noise, and attention is drawn to the implications of the present findings for cardiovascular health under conditions of chronic intermittent noise.
Is Elicitation of the Autonomic Orienting Response Associated With Allocation of Processing Resources?
Authors: Dawson Michael E. , Filion Diane L. , Schell Anne M.
Published: February 2007

Two experiments investigated whether elicitation of the autonomic orienting response is associated with active allocation of processing resources as indexed by the slowing of reaction time to secondary task probes. In Experiment 1, 75 college student subjects performed a dual task consisting of a primary auditory orienting task and a concurrent secondary visual reaction time task. The primary orienting task included task‐relevant tones presented to one car and task‐irrelevant tones presented to the other ear. The last trial of the primary task included an unexpected novel tone presented binaurally. The secondary task consisted of a series of brief light flashes presented at critical times throughout the primary task; the reaction time of the subjects' motor responses to these flashes was measured. Consistent with the resource allocation view of orienting, the results demonstrated that resources were allocated during the primary task tones and the novel tone, and this allocation was greater during the early trials than the late trials of the primary task. However, a directional dissociation was observed in that resource allocation was greater during the task‐irrelevant tone whereas autonomic orienting responses were larger to the task‐relevant tone. Experiment 2 replicated all of these effects and demonstrated that the directional dissociation was sensitive to the predictability and ease of discrimination between the task‐relevant and task‐irrelevant tones. Taken together, these findings indicate that the relationship between resource allocation and autonomic orienting is a reliable but complex one in need of further research.
Acute Emotional and Psychophysiological Effects of Aerobic Exercise
Authors: Roth David L.
Published: February 2007

An experiment was conducted to examine the acute emotional and psychophysiological effects of a single bout of aerobic exercise. Forty active and 40 inactive college students were randomly assigned to an aerobic exercise or a waiting‐period control condition. Self‐report measures of mood and cardiovascular response measures to challenging cognitive tasks were collected before and after the 20‐min exercise/control period to examine any exercise‐induced changes. The results indicated that mood was significantly altered by the exercise activity, with reductions in tension and anxiety specifically evident. Exercise was not found to have any effects on cardiovascular reactivity. A test of aerobic fitness confirmed fitness differences between active and inactive participants, but no mood or reactivity effects related to activity status were obtained. These results suggest that both active and inactive individuals experience acute reductions in anxiety following single bouts of exercise, even in the absence of changes in cardiovascular reactivity. Implications for the continued investigation of the acute effects of exercise are discussed.
Patterns of Autonomic Response During Laboratory Stressors
Authors: Allen Michael T. , Crowell Michael D.
Published: February 2007

The present study was designed to include an index reflecting the influence of parasympathetic nervous system activity on the heart, respiratory sinus arrhythmia, in addition to measures reflecting primarily sympathetic nervous system activity. The inclusion of the parasympathetic index was considered important for two reasons: (a) Past studies have suggested different patterns of autonomic response to qualitatively different laboratory stressors but have had to infer parasympathetic influences more indirectly, and (b) there is evidence that borderline hypertensives may have reduced vagal tone at rest when compared to normotensives. This last point is important for the study of individual differences in cardiovascular reactivity because excessive responsiveness in young normotensives (beta‐adrenergic reactors) has been suggested as a model for studying the precursors of some types of hypertension. Fifty‐one male college students were given a reaction time task, a mental arithmetic task, a cold pressor task, and graded bicycle exercise. A variety of cardiovascular and respiratory measures were collected on each subject. Results indicated significant differences in levels of respiratory sinus arrhythmia during the three tasks and the rest period, giving additional evidence for parasympathetic differences (along with sympathetic differences) in these conditions. Additionally, high beta‐adrenergic reactors did not differ in mean level of respiratory sinus arrhythmia from low reactors either at rest or during the task periods. These results are discussed in the context of previous research.
Premenopausal and Postmenopausal Women Differ in their Cardiovascular and Neuroendocrine Responses to Behavioral Stressors
Authors: Saab Patrice G. , Matthews Karen A. , Stoney Catherine M. , McDonald Robert H.
Published: February 2007

Middle‐aged (45–51 years) women performed four tasks while their heart rate, blood pressure, and plasma catecholamines were measured. The tasks were serial subtraction, mirror image tracing, speech, and postural tilt. The speech task was considered to be particularly relevant to women because of its emphasis on social skills. Fifteen premenopausal women reported menstruating regularly and were tested in the early follicular phase. Sixteen postmenopausal women reported not menstruating for at least 12 months and their hormonal status was verified by serum levels of follicle‐stimulating hormone. Results showed that postmenopausal women exhibited greater increases from baseline in heart rate during all tasks, relative to premenopausal women, with a particularly pronounced increase during the speech task. Postmenopausal women exhibited greater increases from baseline in systolic blood pressure and epinephrine, relative to premenopausal women, during the speech task only. Explanations for the stressor‐specific effect of menopausal status were discussed. The results suggest that reproductive hormones may interact with stressor characteristics to determine middle‐aged women's physiological responses to stress.
Effects of Conditioned Stimulus Fear‐Relevance and Preexposure on Expectancy and Electrodermal Measures of Human Pavlovian Conditioning
Authors: Booth Michael L. , Siddle David A. T. , Bond Nigel W.
Published: February 2007

The present research investigated the effects of fear‐relevance of the conditioned stimulus (CS) and CS preexposure on human electrodermal conditioning and on a continuous measure of expectancy of the unconditioned stimulus (US). Both experiments employed 20 preexposure, 8 acquisition, and 8 extinction trials in a differential Pavlovian conditioning paradigm with shock as the US. In Experiment 1 (N = 48), electrodermal conditioning was retarded by CS preexposure, but was not influenced by fear‐relevance of the CS. Expectancy of the US was retarded by preexposure only in the fear‐relevant condition. In Experiment 2 (N = 48), the CS/US contingencies were embedded in a visual masking task. Preexposure retarded both electrodermal conditioning and US expectancy. Neither measure was influenced by fear‐relevance of the CS. However, fewer subjects in the preexposure condition learned the CS/US relationship and those who did, did so on a later trial than those in the no‐preexposure condition. Thus, the results indicated clear retardation of conditioning as a result of preexposure, but no reliable effect of fear‐relevance.
Effects of a Change in Tone Frequency on the Habituated Orienting Response of the Sleeping Rat
Authors: Johnen Marga , Schnitzler Hans‐Ulrich
Published: February 2007

EEG arousal and heart rate responses to change in tone frequency following habituation training were studied during slow wave sleep in the rat. Rats were exposed to sequences of 12 tone pulses. Habituation stimuli (trials 1–7) had a frequency of 16 kHz. The frequency of the following (test) trials was changed to either 5, 12, 14, 22, or 40 kHz. Hearing level was held constant for all frequencies. Test trials were repeated five times to study rehabituation. The results indicate that heart rate deceleration is an indicator of the orienting reflex and its magnitude is a positive function of the amount of frequency change of the stimulus. Large frequency changes in either direction relative to the habituation frequency lead to re‐evocation of the habituated EEG arousal and heart rate deceleration, with subsequent rehabituation. Small tone‐frequency changes do not result in EEG arousal or heart rate deceleration responses that differ from the responses to the habituated frequency. Heart rate acceleration shows neither short‐term habituation nor significant reaction to any of the test frequencies.
For Distinguished Contributions to Psychophysiology: David Shapiro
Authors: Tursky Bernard
Published: February 2007

At the Twenty‐Eighth Annual Meeting of the Society for Psychophysiological Research, the award for Distinguished Contributions to Psychophysiology was presented to David Shapiro by Bernard Tursky, on behalf of the Society's Awards Committee. Following is the text of the citation given at the meeting on October 22, 1988.
Stability of Myoelectric Slow Waves and Contractions Recorded from the Distal Colon
Authors: Enck Paul , Whitehead William E. , Shabsin Harry , Nikoomanesh Parviz , Schuster Marvin M.
Published: February 2007

The stability of physiological activity in the distal colon was investigated by recording 5–6 hours in each of 6 healthy adults. Contractions and myoelectric slow waves were recorded from the sigmoid colon (25–30 cm from the skin surface) and rectum (10–15 cm), and pressure waves were recorded from the proximal small intestine. The activity index (sum of areas of all waves divided by recording time) varied by 200% to 800% across 4‐min samples for all motility and myoelectric slow wave recordings. Spectral analysis indicated that contractile activity waxed and waned in a cycle with a period of 40–55 min in the colon and 64–80 min in the small intestine. Myoelectric slow wave activity in the colon cycled with a period of 30–40 min. Contractile activity in the sigmoid colon was correlated with similar activity in the rectum, but myoelectric slow wave activity in the colon was not correlated with myoelectric slow waves in the rectum. The frequency composition of contractions and slow waves was unstable over time.
Within‐Channel Selection and Event‐Related Potentials During Selective Auditory Attention
Authors: Okita Tsunetaka
Published: February 2007

Event‐related potentials were recorded from subjects who listened selectively to stimuli in one of two input channels (ears). The stimuli were random sequences of five vowels and a tone pip. In separate experimental runs, the difficulty of within‐channel selection was manipulated by designating either tone (T), one vowel (1V), or two vowels (2V) as targets. An attention‐related negativity (Nd) was observed for attended nontarget vowels irrespective of the target difficulty, but the early, centrally maximal phase of Nd was substantial only for the one‐vowel and two‐vowel conditions. The Nd between its early and late peaks was significantly larger for the two‐vowel condition than for the one‐vowel and tone conditions. The 2V minus 1V difference in Nd had a closely similar distribution to the early Nd. These target difficulty effects were interpreted as suggesting that the early Nd recorded in two‐selection tasks can be related to a within‐channel selection process as well as a between‐channel selection process. The more anteriorly distributed, later phase of Nd was suggested to be rather insensitive to the difficulty of the within‐channel selection. The nature of the within‐channel selection underlying the early Nd was discussed in relation to controlled memory search operations.
The Effects of Consent Procedures on the Psychophysiological Assessment of Anxiety: A Methodological Inquiry
Authors: Farha Jennifer G. , Sher Kenneth J.
Published: February 2007

The present study investigated the effects of informed consent regarding upcoming, aversive stimuli on autonomic and self‐report measures of anxiety. Physiological and self‐report measures were recorded prior to the subject receiving information regarding the nature of the upcoming stressor (naive baseline block), following the receipt of this information (informed baseline block), during the anticipation of the stressor (anticipation block), and following the expected stressor (post‐stressor baseline block). Examination of mean levels of autonomic activity during the naive and informed baseline blocks and the patterns of correlations involving those blocks indicated that the naive and informed baseline blocks were noncomparable. Implications of these findings for experimental design and clinical assessment are discussed.
Stimulus Miscuing, Electrodermal Activity, and the Allocation of Processing Resources
Authors: Packer Jeanette S. , Siddle David A. T.
Published: February 2007

The present research investigated the effects of stimulus miscuing on electrodermal responding, dishabituation, stimulus expectancy, and the allocation of processing resources as assessed by reaction time to a secondary task probe stimulus. In both experiments, a control group received 33 S1‐S2 pairings intermixed with 33 S3‐alone presentations. For the experimental group, S2 was miscued by its presentation following S3 on 4 trials. Experiment 1 (N=24) demonstrated reliable electrodermal responding when S2 was miscued by S3 and subsequent dishabituation when S2 was re‐presented following S1 on the next trial. A continuous measure of S2 expectancy revealed that S2 was not expected to follow S3 on miscuing trials. On re‐presentation trials, S2 was not expected to follow S1. Experiment 2 (N=24) employed probe reaction time as the dependent variable. White noise probe stimuli of 500‐ms duration were presented 300 ms following the onset of S2 on miscued trials and on re‐presentation trials. Reaction time to probes presented during miscued presentations of S2 was slower in the experimental group than in the control group. Reaction time on S2 representation trials was also slower in the experimental group than in the control group. The results are interpreted to indicate that both the miscuing of S2 by S3 and its re‐presentation following S1 on the next trial command processing resources. The results are discussed in terms of current theories of associative learning.
Microcomputer Servo‐controlled Bicycle Ergometer System for Psychophysiological Research
Authors: Laperriere Arthur R. , Van Dercar David H. , Shyu Liang Yu , Ward Michael F. , McCabe Philip M. , Perry Arlette C. , Mosher Patricia E. , Schneiderman Neil
Published: February 2007

Steady state exercise is widely used for psychophysiological studies in which a constant heart rate at a predetermined level is desired. We have developed a microcomputer servo‐controlled bicycle ergometer system that can be used for administering steady state exercise. Fourteen healthy male subjects, with a wide range of fitness levels (measured by Vo2max) were exercised to either a fixed workload (130 watts) or a predetermined heart rate level (servo‐heart rate) of 122 bpm (i.e., 65% of maximum calculated heart rate for the sample). Servo‐heart rate was implemented using a feedback loop that automatically adjusted workload to compensate for immediate variations in heart rate, resulting in a more consistent heart rate. Heart rate varied from the predetermined value by 17 bpm during fixed workload but only 3 bpm during servo‐heart rate (p<.05). Therefore, by using the microcomputer servo‐controlled bicycle ergometer, heart rate was maintained at a predetermined level regardless of the subject's fitness level. 2max and workload during servo‐heart rate were significantly correlated (r= .85, p<.05). Therefore, the workload necessary to maintain heart rate at a constant level may provide an approximate index of aerobic fitness level.
A Procedure for Using Multi‐Electrode Information in the Analysis of Components of the Event‐Related Potential: Vector Filter
Authors: Gratton Gabriele , Coles Michael G. H. , Donchin Emanuel
Published: February 2007

This paper describes a procedure, Vector filter, based on a multiple regression model, which decomposes the event‐related brain potential into components on the basis of scalp distribution. It is assumed that the voltage values observed at several electrode sites at any point in time are given by the linear combination of a set of components and background noise and that the scalp distribution of each component is invariant and known. Each component's scalp distribution is expressed by a set of weights, one for each electrode. The amplitude of the component, at any point in time, is then derived using a least squares criterion. Unlike other component decomposition procedures, Vector filter can be applied when the latency of a component varies as a function of trial, condition, or subject population. We review two problems in the use of the procedure: the selection of the set of components, and the derivation of the scalp distribution of each of the components. Two applications of the procedure are discussed: identification of the component structure of an event‐related potential waveform, and filtering of a waveform for a particular component.
Multiple Sources of P3b Associated with Different Types of Information
Authors: Ruchkin Daniel S. , Johnson Ray , Canoune Howard L. , Ritter Walter , Hammer Muriel
Published: February 2007

This experiment investigated how the P3a, P3b, and Slow Wave components of the event‐related brain potential (ERP) respond to manipulations of the nature, timing, and extent of information delivery. There were two experiments in which the total amount of task information was distributed between pairs of successive stimuli (S1 and S2) within each trial. The task was to predict the relation between S1 and S2. In Experiment 1, the S1 could resolve no, partial, or all uncertainty with respect to the prediction outcome (correct or incorrect). Each S1 delivered three types of information: 1) outcome information–which resolved the subjects' uncertainty about the correctness of their prediction: 2) procedural information–which resolved uncertainty about how much outcome information would be delivered by S1; and 3) memory information–the identity of S1, which had to be stored for subsequent comparison with S2. In Experiment 2, the activity of these components was contrasted in two conditions in which the S1 delivered either memory information alone or both memory and procedural information. P3a and Slow Wave were sensitive only to outcome information. P3b was sensitive to all three types of information, and its scalp topography varied as a function of the type of information. The topographic variations indicate that P3b is not a unitary phenomenon but rather is a composite of activity arising from multiple intracranial sources of bioelectric activity.
Issues in Biometrics: Offset Potentials and the Electrical Stability of Ag/AgCl Electrodes
Authors: Tassinary Louis G. , Geen Thomas R. , Cacioppo John T. , Edelberg Robert
Published: February 2007

There has been a continuing interest in many areas of psychophysiological research in the quantification of slow wave bioelectric potentials recorded from the surface of the skin. However, surprisingly little research has focused specifically on methods for stabilizing and minimizing the offset potentials of the sintermetallic Ag/AgCl surface electrodes commonly used in such noninvasive bioelectric measurement. To provide empirically based recommendations in this regard, we contrasted the effects of three common storage methods (air dry vs. saline vs. carbon rod) on the two distinct types of Ag/AgCl surface electrodes (sintermetallic vs. electrolytic) under simulated experimental conditions. The obtained results confirm that minimum offset potentials and maximum stability for electrolytic Ag/AgCl electrodes are obtained when they are stored in a 0.9% NaCl solution with their leads shorted together and connected in parallel to a carbon rod partially immersed in the solution (cf. Cooper, 1956). In addition, the pattern of results suggested that the inter‐session unshorted storage of sintermetallic electrodes in a mild saline solution is to be recommended over either shorted saline storage in parallel with a carbon rod or unshorted dry storage.
Parietal P3 Response as an Indicator of Stimulus Categorization: Increased P3 Amplitude to Categorically Deviant Target and Nontarget Stimuli
Authors: Nasman Victoria Tepe , Rosenfeld J. Peter
Published: February 2007

Two experiments were performed in which we compared the effects of selected non‐deviant versus categorically deviant stimuli on parietal P3 under a variety of conditions in which one, both, or neither stimulus was a target of an experimental task. Subjects were repeatedly presented with series of 8 numeric stimuli and 1 alphabetic (Deviant) stimulus. P3 amplitudes to target and nontarget Deviant stimuli were consistently and significantly larger than to other, non‐deviant targets and nontargets, respectively. Nontarget Deviant stimuli evoked P3 amplitudes comparable to those evoked by low‐probability non‐deviant targets.

The observed differences indicate that P3 amplitude is a sensitive indicator of perceived category differences, and that the effect of category deviance on parietal P3 amplitude is independent of task response classification (target or nontarget) and of response probability.