bluuebunny/crossref_metadata_2025 huggingface dataset:
Voluntary Movement and Excitability of Cutaneous Eyeblink Reflexes
Authors: Sanes Jerome N.
Published: February 2007

Reflex responses from eyelid muscles were evaluated when subjects prepared to or made brief or sustained voluntary contractions of eyelid or forearm muscles in a signaled reaction time task. The eyeblink reflex consists of an early and unilateral response, R1, and a longer latency bilateral response, R2. A similar pattern of reflex excitability was observed for all phasic movements. The R1 was transiently potentiated by the warning stimulus, increased again at the end of the preparatory period, increased more in the reaction interval and immediately after movement onset, and finally declined to control levels by 500 ms after onset of voluntary movement. The R2 responses were typically depressed at the same times that R1 responses were enhanced. When sustained contractions were performed and reflexes were elicited after movement eyelid onset, the patterns of early R1 enhancement and R2 depression occurred, both for about 500 ms, and gave way to continued R1 and also R2 enhancement as long as eyelid movement continued. The different behavioral responses of R1 and R2 reflect differences in the physiological properties of the separable neuroanatomical pathways for the two eyelid reflex responses.
Amplitude and Bandwidth of the Frontalis Surface EMG: Effects of Electrode Parameters
Authors: van Boxtel A. , Goudswaard P. , Schomaker L.R.B.
Published: February 2007

In the present investigation, the frontalis surface EMG was differentially recorded during static voluntary submaximal contractions. First, mean rectified EMG (MREMG) and EMG signal bandwidth were examined for two different bilateral EMG derivations (superior and inferior) with the electrodes placed in horizontal direction and two unilateral derivations (left and right) with the electrodes placed in vertical direction. MREMG was significantly different between the four derivations but absolute differences were small. Bandwidth also varied significantly with derivation. Second, the influence of inter‐electrode distance and electrode size was examined for unilateral derivations. The influence of inter‐electrode distance on MREMG was significant but the absolute effect was marginal. We suggest that a clear effect is to be expected only within the range of small distances (smaller than 10 mm). The significant effect disappeared when MREMG was expressed as proportion of the MREMG during maximal contraction. This normalization seems to allow better intra‐individual or inter‐individual comparisons of integrated EMG, especially when different recording methods are used. The influence of inter‐electrode distance on bandwidth was not significant. Electrode size had no significant influence on MREMG and bandwidth. EMG power spectra indicated that integrated frontalis EMG can be validly measured only when using recording equipment with a frequency response of 5–500 Hz.
Cardiovascular Effects of Mental Arithmetic in Type A and Type B Females
Authors: Lane James D. , White Alice D. , Williams Redford B.
Published: February 2007

The cardiovascular responsivity of women demonstrating the Type A coronary‐prone behavior pattern was investigated by presenting female Type A and Type B subjects with a challenging mental arithmetic task. Female subjects responded to the task with elevations in heart rate, blood pressure, and forearm blood flow, but did not show the active vasodilatation in the forearm vasculature seen in males in an earlier study. Type A females as a group were not hyperresponsive compared to Type B. However, measures of Type A behavior interacted with family history of hypertension such that, in the subgroup with a positive family history, the Type A behavior pattern was associated with larger cardiovascular responses. The results suggest that sex differences could be present in the expression of the cardiovascular concomitants of Type A behavior. Both gender and family history of cardiovascular disease may represent additional dimensions in the understanding of the pathological mechanisms linking Type A behavior and coronary disease.
Peak Alpha Frequency of EEG during a Mental Task: Task Difficulty and Hemispheric Differences
Authors: Osaka Mariko
Published: February 2007

To investigate the effect of task difficulty on the alpha wave, bilateral EEGs were recorded from frontal and occipital locations from 5 male and 5 female students while they were engaged in two arithmetic (simple addition, SA, and complex addition, CA) and two visuo‐spatial (visual imagery, VI, and mental rotation, MR) tasks. During both the arithmetic and the visuo‐spatial tasks, peak alpha frequency of power spectrum increased significantly above the resting level. Moreover, the frequency shift was significantly larger in the CA and MR conditions than in the SA and VI conditions. The shift increased as the task difficulty increased. A hemispheric effect was found: the peak alpha frequency increased in the left rather than in the right during the arithmetic tasks whereas it increased in the right rather than in the left during the visuo‐spatial tasks.
Effects of Cigarette Smoking on Bilateral Skin Conductance
Authors: Boyd Gayle M. , Maltzman Irving
Published: February 2007

Bilateral skin conductance was recorded from 8 male and 8 female cigarette smokers and from 8 male and 8 female nonsmoker control subjects on two different days. On one day smokers smoked a cigarette prior to the recording session and on the other they remained abstinent. Subjects also engaged in tasks designed to differentially involve the cerebral hemispheres. SCR asymmetry was measured using two different indices. During both the resting and task periods smokers had larger SCRs in their right than left hands following smoking. Unlike control subjects during the first recording session, smokers did not show task related changes in SCR asymmetry. During tasks smokers showed smaller SCRs in both hands following smoking than following abstinence. Changes in SCR asymmetry associated with smoking were seen in subjects who smoked more cigarettes, reported more subjective craving, were more introverted, and indicated a preference for cognitive processes and strategies associated with the left hemisphere. Results are discussed in terms of relative involvement of the cerebral hemispheres following smoking and smoking abstinence.
Forty Hertz EEG Activity in Dementia of the Alzheimer Type and Multi‐Infarct Dementia
Authors: Loring David W. , Sheer Daniel E. , Largen John W.
Published: February 2007

High frequency EEG activity within the 40 Hz band was examined at rest and during two problem solving tasks in patients with presumptive diagnoses of either dementia of the Alzheimer type (DAT) or Multi‐Infarct Dementia (MID), and in normal elderly subjects. The DAT patients differed significantly from normals and MID subjects, exhibiting both decreased rates of 40 Hz EEG activity and no task‐appropriate pattern of cerebral lateralization. Although MID patients did not differ from controls during baseline, significantly less 40 Hz activity was present during performance of a sentence repetition task. Evidence for normal task‐specific asymmetry was present in the MID and control groups. The results suggest that patterns of 40 Hz EEG activity may be of utility in the early diagnosis of DAT. Further, the 40 Hz rhythm appears able to discriminate between patient populations that present with similar patterns of dementia.
Second Thoughts: Multiple P300s Elicited by a Single Stimulus
Authors: Johnson Ray , Donchin Emanuel
Published: February 2007

In a previous report (Johnson & Donchin, 1978), we manipulated the discriminability of tone pairs that delivered feedback information in a time‐estimation paradigm. As in other experiments using feedback stimuli, the event‐related potentials elicited by these stimuli did not return to baseline in the 800‐ms poststimulus interval. Since we were interested in this “Slow Wave'’activity, the poststimulus interval was lengthened to 1500 ms. Averages revealed that a second positive peak was present for some of the individual subjects. To investigate this activity further, the filtered singletrial waveforms were inspected visually. These data were characterized by the presence of one, and occasionally two, positive peaks, with highly variable latencies, following the P300. These peaks were indistinguishable in frequency and general appearance from the P300s elicited by the feedback stimuli. After latency adjusting the waveforms on the peak of the second positive wave, amplitude and latency were quantified. Whereas P300 amplitude was directly related to stimulus discriminability and positive feedback elicited larger P300s than negative feedback, the amplitude of the second positive wave was constant across levels of discriminability and the same for both types of feedback. In contrast, the latencies of both waves were inversely related to stimulus discriminability and shorter following positive feedback than negative feedback. Evidence is presented to support our contention that these additional positive peaks represent P300 activity. The data are discussed in terms of what these multiple P300s reveal about human information processing.
Effects of UCS Probability on the Contingent Negative Variation and Electrodermal Response During Long ISI Conditioning
Authors: Backs Richard W. , Grings William W.
Published: February 2007

Nine subjects participated in a long ISI, trace conditioning paradigm. Tone CSs, at three different frequencies, signaled that a loud noise UCS would occur with either a .17, .50, or .83 probability. Subjects were instructed on the CS‐UCS contingencies. To avoid effects of differential motor preparation, two button presses were required on each trial. Button presses were signaled by lights, one second after the point at which the UCS would occur. EDR was recorded from the nonpreferred hand; EEG was recorded from the Cz and Pz sites. Only responses to the CSs were quantified. For the EDR, the first interval response was largest at the .83 UCS probability level. The CNV was more negative at the .50 UCS probability level than at the .17 and .83 UCS probability levels across the ISI. An early component of the CNV was also most negative at the .50 UCS probability level, and was larger at Cz than at Pz. A late CNV component did not differ significantly among UCS probability levels. It was concluded that the EDR and CNV reflect different properties of the associative process between paired stimuli.
Mathematical Models of the Event‐Related Potential
Authors: Hunt Earl
Published: February 2007

The Event‐Related Potential is assumed to be composed of several underlying component waveforms. Principal Components Analysis is a statistical technique that has been used to uncover the components by analysis of the observed waveform. The mathematical assumptions behind Principal Components Analysis are examined, and their plausibility in the ERP application is questioned. The problem of plausibility is serious because Principal Components Analysis may not recover component waveforms accurately if the assumptions behind the method are violated. The nature of the inaccuracies is illustrated by an analysis of simulated waveforms constructed from known components.
The Development of Sustained Visual Attention in Infants from 14 to 26 Weeks of Age
Authors: Richards John E.
Published: February 2007

The development of sustained visual attention was examined in infants cross‐sectionally at 14, 20, and 26 weeks of age. Heart rate, heart rate variability, and respiratory sinus arrhythmia were measured in a 5‐min baseline period. Two methods for measuring visual attention were used. The “infant control” method consisted of checkerboard presentations which were terminated when the infant looked away from them. The “interrupted stimulus” method consisted of a blinking panel in addition to the checkerboard patterns in order to attempt to actively terminate the fixation. The visual and cardiac responses during the interrupted stimulus method were more highly correlated with baseline respiratory sinus arrhythmia than were the responses during the infant control trials. The long latency heart rate responses during the interrupted stimulus trials showed a developmental change toward more mature response patterns from 14 to 26 weeks of age. It may be concluded that: 1) sustained attention, measured with the interrupted stimulus method, increases from 14 to 26 weeks of age; and 2) baseline respiratory sinus arrhythmia is correlated with sustained attention responses and their development.
Scoring Criteria for Response Latency and Habituation in Electrodermal Research: A Critique
Authors: Levinson Douglas F. , Edelberg Robert
Published: February 2007

Recent evidence, particularly in research on the skin conductance orienting response (SCOR) in schizophrenia, suggests that differences in scoring criteria may be important sources of error and variability in studies of electrodermal responses to discrete stimuli and their habituation. Although a wide variety of response latency criteria have been used in published studies, empirical evidence suggests that responses occur in a narrow and early post‐stimulus time window. Data are presented demonstrating that the intra‐subject variability of response latency is low when responses are scored within a narrow time window, but that broader time windows include more variable‐latency responses that may represent spontaneous activity. The commonly‐used criterion of three no‐response trials as an habituation endpoint may also introduce contamination by spontaneous activity; available evidence favors a two‐trials criterion. Analyses such as the ones presented here permit testing of the specificity of scoring criteria for responses elicited by experimental stimuli.
The Residual After Correcting Event‐Related Potentials for Blink Artifacts
Authors: Berg Patrick
Published: February 2007

Data from an event‐related potential (ERP) study using central scalp locations on 36 subjects with an oddball paradigm were analyzed to determine which of four linear regression methods was the most effective in correcting for eyeblink artifacts. The best method was then employed to determine how well the artifact was removed from independent EEG data from 10 subjects, and from the ERP data. The error remaining after correction, the residual, is a systematic time function related to the blink. Differences between corrected and artifact‐free ERPs are explicable in terms of the residual and are a function of blink latency in the corrected ERPs. The most marked difference was a positivity on Pz of up to approximately 3 μ V occurring after the mean blink latency. These results indicate that caution is necessary when correcting data for eyeblink artifacts if blink frequency and latency are systematically related to experimental condition. The residual is probably mostly a reflection of physiological events correlated with the eyeblink.
General Autonomic Components of Motion Sickness
Authors: Cowings Patricia S. , Suter Steve , Toscano William B. , Kamiya Joe , Naifeh Karen
Published: February 2007

This report refers to a body of investigations directed toward the examination of autonomic nervous system responses to motion sickness. Heart rate, respiration rate, finger pulse volume, and basal skin resistance were measured on 127 men and women before, during, and after exposure to a nauseogenic rotating chair test. Significant changes in all autonomic responses were observed across the tests (p<.05). Significant differences in autonomic responses among groups divided according to motion sickness susceptibility were also observed (p<.05). Results suggest that the examination of autonomic responses as an objective indicator of motion sickness malaise is warranted and may contribute to the overall understanding of the syndrome.
Phasic Cardiac Reactivity to Psychological Stress as a Function of Aerobic Fitness Level
Authors: Shulhan Donna , Scher Hal , Furedy John J.
Published: February 2007

Cardiovascular adjustments to physical exertion are known to be affected by aerobic fitness level. This raises the possibility that the cardiovascular responses associated with psychological stress may also be related to aerobic fitness. This study was undertaken to determine if phasic cardiac reactivity to stress would be affected by aerobic fitness level, and to make inferences regarding the autonomic mechanisms which might mediate such an effect.

Twenty‐four males were given a standard physical fitness test and then divided into high and low aerobic fitness level groups. Within two weeks of this assessment, the heart rate and electrocardiographic T‐wave amplitude responses of these subjects were monitored during the performance of hard and easy versions of a mental arithmetic task. Analysis of the heart rate data revealed no aerobic fitness level effect. There was, however, greater T‐wave amplitude attenuation in the low as compared to the high aerobic fitness level group on hard trials. This pattern of results suggests that psychologically‐elicited sympathetic cardiac reactivity is reduced by enhanced aerobic fitness level.
The Effects of Psychological and Environmental Stressors on Peristaltic Esophageal Contractions in Healthy Volunteers
Authors: Young Larry D. , Richter Joel E. , Anderson Karen O. , Bradley Laurence A. , Katz Philip O. , McElveen Lisa , Obrecht W.F. , Dalton Chris , Snyders R. Miller
Published: February 2007

The relationship between various stressful stimulus conditions, measures of anxiety, and altered esophageal motility was investigated in mo experiments employing normal adult volunteers. In Experiment 1, subjects were administered separately I00dB continuous white noise and a cold pressor task. In Experiment 2. subjects were administered in a counterbalanced order intermittent and unpredictable bursts of 100dB white noise and a cognitive task consisting of solvable and unsolvable discrimination problems. Results of both experiments showed that the amplitudes of peristaltic esophageal contractions and levels of state anxiety self‐reports were significantly higher during periods of stress than during preceding baseline periods. Furthermore, in Experiment 2, esophageal contraction velocities and anxiety‐related behaviors were significantly greater during stress periods than during baselines. Contrary' to previous studies, few abnormal tertiary esophageal contractions were elicited by stress. The present results identify increased amplitude of the peristaltic contractions as the primary esophageal response to stress. Technological and methodological differences between this study and previous Investigations of affective disturbance among patients with chronic esophageal chest pain also are examined.
Respiratory Sinus Arrhythmia as an Index of Parasympathetic Cardiac Control During Active Coping
Authors: Grossman Paul , Svebak Sven
Published: February 2007

Psychophysiological studies concerning tonic cardiac responses to stressor tasks have tended to emphasize beta‐adrenergic effects and to neglect parasympathetic influences and sympathetic‐parasympathetic interactions. Much recent evidence indicates that both within‐ and between‐individual variations in cardiac parasympathetic heart rate (HR) control can be easily and reliably assessed by measuring the magnitude of respiratory sinus arrhythmia (RSA). Therefore, we used RSA to index cardiac vagal responses to two active coping tasks. Both tasks consisted of the same video game, in one condition with threat of shock for inferior performance, and in the other without such threat. Twenty subjects underwent both tasks (counterbalanced over subjects), plus a preceding resting baseline period. HR and RSA were continuously measured. Results suggested that cardiac parasympathetic activity was diminished from rest to task, contributing to heart rate responses. Exaggerated HR responses were also associated with extreme parasympathetic withdrawal. Furthermore, task condition X sequence of presentation interaction effects showed that threat of shock was particularly effective in elevating HR and reducing RSA when the threat was presented during the first task condition. A repeated‐measures analysis of covariance of HR, attempting to remove the effects of parasympathetic influences upon HR, suggested that sympathetic influences upon HR exceeded any reciprocal vagal effects during the threat condition for those subjects exposed to the threat task first. The findings indicate the importance of considering stress‐related parasympathetic effects upon HR as well as sympathetic‐vagal interactions.
Modification of the Acoustic Startle Reflex by a Tactile Prepulse: The Effects of Stimulus Onset Asynchrony and Prepulse Intensity
Authors: Blumenthal Terry D. , Gescheider George A.
Published: February 2007

The present experiments were designed to assess the effects of a tactile prepulse on the acoustic startle response in human adults. Acoustic startle stimuli were presented via loudspeaker, and tactile prepulse stimuli were presented by a vibrator contactor on the thenar eminence of the right band. In Experiment 1 stimulus intensity was 20dB above each individual subject's psychophysical tactile threshold and stimulus onset asynchrony (lead time) was 50, 100, 200. or 300 ms, with a control condition in which no prepulse was presented. In Experiment 2, the same stimuli were used, except that tactile prepulse intensity was varied (−4, 0, 4, 8, 12, and 20 dB above each subject's psychophysical threshold), and lead time was constant at 200 ms. Reflex eyeblink responses were assessed from integrated periorbital etectromyographic (EMG) activity. Compared to responding in the control condition (no prepulse), a prepulse at a 50‐ms lead time facilitated responding by increasing response amplitude and decreasing latency. At a lead time of 100 ms, the amplitude increase was no longer found, but the latency decrease was still apparent, as was a decrease in response probability. At lead times of 200 and 300 ms, responding was inhibited, as shown by‐decreased response amplitude and probability. At a lead time of 200 ms. tactile prepulses as low as 8dB above threshold caused a reduction in response amplitude, but no effects of prepulse intensity on response probability or latency were found. The prepulse intensity and lead time effects shown in the present study demonstrate that the presentation of a brief, near‐threshold tactile prepulse can either facilitate or inhibit an acoustically‐elicited startle response, depending upon the temporal relationship between the two stimuli. Also, the different measures of the startle response reflect this modification in different ways.
Proximal Effects of Two and Four Hour Naps Within Extended Performance Without Sleep
Authors: Webb Wilse B.
Published: February 2007

Subjects performed on a battery of tests for 3 days and nights with minimal or no sleep. Three nap schedules were investigated: 2 hrs from 0800‐1000 following Nights 1 and 2 (morning naps); 2 hrs from 2200–2400 prior to Nights 2 and 3 (evening naps): 4 hrs from 2000–2400 prior to Night 2. There was n no‐nap control group. Measures from a 30‐min addition task and subjective measures of sleepiness were analyzed. The measures used were from approximately 2 hrs before and 2 hrs after the experimental conditions. The data show an ameliorative proximal effect of naps through at least the second night.
Thirty‐Six Hour Correspondence Between Performance and Sleepiness Cycles
Authors: Lavie P. , Gophe D. , Wollman M.
Published: February 2007

The present work investigates the correspondence between rhythmicity in performance efficiency and sleepiness. Eight subjects kept a repeating schedule of 7 Min in bed, 13 min awake out of bed, for two 36‐hr periods. Each 36‐hr period followed 28 hrs of sleep deprivation. Periods were separated by a one‐week interval. Time in bed was subject to two experimental conditions, either attempting or resisting sleep. During each 13‐min period outside the bedroom, subjects were tested on a choice reaction time task with three levels of movement difficult). In both the attempting sleep and resisting sleep conditions, reaction time and movement lime showed marked circadian modulation, generally matching the sleepiness cycle. There was no interaction between movement difficulty and (he effects of sleep loss. There were no significant differences in total sleep between the conditions of attempting and resisting sleep; however, subjects instructed to resist sleep had slower reaction times and less stable movement times. The significance of these findings is discussed in terms of differences between attentional mechanisms and multiple processing resources. Results support a theory that the performance and sleep wake cycles are not causally related but rather, may be regulated independently.
The Effects of Piracetam Upon Visual Event‐Related Potentials in Dyslexic Children
Authors: Conners C.K. , Reader M. , Reiss A. , Caldwell J. , Caldwell L. , Adesman A. , Maver L. , Berg M. , Clymer R. , Erwin R.
Published: February 2007

Twenty‐nine dyslexic children (mean age 10 yrs) were randomly assigned to piracetam (3.3 gr/d) or matching placebo in a 36‐week double‐Mind study. Event‐related potentials (ERPs) were obtained at the end of treatment from a vigilance paradigm which required a response to letter‐matches or form‐matches. The drug group showed a significant advantage in letter‐bits compared with placebo, and a reduced variance in reaction time. The drug increased the amplitude of three factors from a principal components analysis of ERPs, and was interpreted as increasing a processing negativity when stimuli were letters. Effects upon the prestimulus baseline for letter‐hits were interpreted as faster termination of a CNV under drug for letter‐pairs. Latency of early N100 components were faster under drug, suggesting improved feature analysis. It is concluded that piracetam enhances feature analysis and increases attentional resources among dyslexics when the stimuli are recognized as having linguistic significance.
Effects of Experimentally‐Induced Sleep Fragmentation on Sleep and Sleepiness
Authors: Magee Jon , Harsh John , Badia Pietro
Published: February 2007

The effects of two levels of sleep fragmentation on sleep and daytime sleepiness were investigated in young adult males. Experimental subjects were informed while awake that tones would be presented periodically throughout the night and that their task was to terminate the tone by taking a deep breath. Eight subjects received tones after each minute of sleep and 8 received tones after each 4 min of sleep. Control subjects (N=8) HI did not receive (ones. The subjects were tested for daytime sleepiness using the Multiple Steep latency Test. It was found that: 1) subjects responded reliably lo tones presented during sleep; 2) behavioral control was accompanied by brief electro‐physiological indices of arousal on almost all trials, and occasionally led to fall awakenings; 3) sleep was markedly altered in the 1‐min condition; 4) a relatively small effect on sleep (reduced stage 4 sleep) was produced by the 4‐min condition, and 5) daytime sleepiness was increased by the 1‐min condition but not the 4‐min condition. It was concluded that the most parsimonious explanation of these results is (he Continuity of Sleep hypothesis.
Event‐Related Potentials to Breaks in Sequences of Alternating Pitches or Interstimulus Intervals
Authors: Nordby Helge , Roth Walton T. , Pfefferbaum Adolf
Published: February 2007

Fourteen subjects were run in paradigms designed to explore event‐related brain potentials (ERPs) elicited by breaks in alternations in pitch or interstimulus interval. In the Pitch paradigm, tones of 500 Hz or 1000 Hz were presented in alternation at regular interstimulus intervals of 800 ms. In the Rhythm paradigm, a single tone, either 500 Hz or 1000 Hz, was presented at interstimulus intervals alternating between 400 ms and 800 ms. Breaks in the Pitch paradigm consisted of a single repetition of a pitch, and in the Rhythm paradigm of a single repetition of the 400‐ms interstimulus interval. Breaks occurred with a 10% probability in both cases. Subjects read while stimuli were being presented.

A N210 wave of about 3.5 μV was elicited by breaks in pitch pattern but not by breaks in rhythm. That it was largest (most negative) frontally suggests that it was a type of mismatch negativity. Analysis of waveforms constructed by subtracting ERPs to standards from ERPs to breaks confirmed these results. Thus we conclude that the system triggering mismatch negativity can encode the temporal ordering of pitches.
Microcomputer Automated System for Measuring Systolic Time Intervals in Response to Exercise and a Psychophysiological Task
Authors: VanDercar David H. , Laperriere Arthur R. , Shyu Liang Yu , Ward Michael F. , McCabe Philip M. , Perry Arlette , Schneiderman Neil
Published: February 2007

A microcomputer automated system for measuring systolic time intervals is described. Electrocardiogram, phonocardiogram, and carotid pulse tracings were measured in 38 healthy male subjects during baseline conditions and during either exercise on a bicycle ergometer or a video‐game task. These measurements were recorded on both a traditional 3‐channel ECG recorder and the computerized system. Both methods of recording systolic time intervals were independently scored by two different experimenters. In this way, interrater reliability of hand‐scoring, intermethod reliability between hand‐scoring versus computer‐scoring, and interrater reliability of computer‐scoring could be assessed.

The interrater reliabilities of hand‐scored systolic time intervals were generally above .90, ranging from .73 for left ventricular ejection time to .99 for R‐R intervals of the ECG, with a mean of .92. The intermethod reliability of the computer versus hand‐scored systolic time intervals also proved to be generally above .90, ranging from .76 for S1‐S2 components of the phonocardiogram to .99 for R‐R, with a mean of .94. The interrater reliabilities of the computer‐scored systolic time intervals were all above .90, ranging from .93 for S1‐S2 to .99 for R‐R, with a mean of .98.

These data indicate that the computerized method of scoring systolic time intervals is at least as reliable as the more traditional scoring of paper tracing.
Scoring Criteria for Electrodermal Habituation: Further Research
Authors: Vossel Gerhard , Zimmer Heinz
Published: February 2007

In the context of Levinson and Edelberg's critique of scoring criteria for electrodermal habituation, the present study examined the question of whether trials‐to‐habituation scores based on two no‐response trials are superior to scores based on three no‐response trials. Male students (N=120) performed two identical habituation experiments on two consecutive days and their skin conductance responses based on a short latency window of 1–3 s were analyzed. In each experiment subjects received 20 presentations of a 1000 Hz tone at 65dB. Results showed that three‐trials scores were higher overall and that the distributions of three‐ and two‐trials scores differed. On the other hand, the twoscores had comparable retest‐reliabilities, displayed similar correlations with regression indices and resting nonspecific activity, and reliably reflected the changes in habituation speed from the first to the second session. Furthermore, three‐ and two‐trials scores were found to be highly interrelated. It was concluded that the findings obtained for our particular sub‐population of male students do not favor one or the other of the two scoring methods for trials‐to‐habituation scores and that the establishment of standardized scoring criteria should be attempted.
Human Brainstem Auditory Evoked Potentials Fail to Provide Evidence of Efferent Modulation of Auditory Input During Attentional Tasks
Authors: Connolly John F. , Aubry Karen , McGillivary Nicole , Scott Donald W.
Published: February 2007

Efferent modulation of auditory input at the level of the brainstem during attention‐demanding tasks has been described in animal studies. Attempts to demonstrate these effects in humans have produced conflicting results, however. These studies are reviewed with particular reference to those animal experiments that have demonstrated peripheral effects. The human experiments have used a number of attentional conditions which have not been related either to each other or to the successful animal work. Two of the most important conditions in these studies–the use of an intermodal attention task and the manipulation of attentional states–have been examined rarely or not at all in the human research. Two experiments were conducted to investigate the possibility of attention‐related effects on the human brainstem auditory evoked potential. These experiments were designed to examine experimental conditions common to both successful and unsuccessful attempts to demonstrate attention‐driven efferent modulation at the periphery in humans. Also examined was the gradation of attention effects on efferent modulation demonstrated in animals but never studied in humans.

No significant changes in either the latency or the amplitude of the brainstem auditory evoked potential were found in any of the attention‐demanding conditions. Results are discussed in terms of psychophysiological theories of attention. Also, the interpretation of the most recent animal work is questioned.
Effects of Smoking/Nicotine on Anxiety, Heart Rate, and Lateralization of EEG During a Stressful Movie
Authors: Gilbert David G. , Robinson John H. , Chamberlin Carl L. , Spielberger Charles D.
Published: February 2007

The effects of smoking cigarettes with differing FTC nicotine deliveries on anxiety and EEG activity were evaluated in 40 smokers who were compared with 40 non‐smokers, matched for age and gender. Following smoking (sham‐smoking in the case of the non‐smokers), the participants viewed a stress‐inducing movie. Smoking higher‐nicotine delivery cigarettes during the movie, as compared to smoking low‐nicotine control cigarettes, was associated with reductions in anxiety and right hemisphere activation, increased heart rate, and enhancement of the ratio of left‐hemisphere parietal EEG activation to right‐hemisphere activation. These results are interpreted as indicating that the anxiolytic effects of nicotine may be mediated by the right hemisphere. The EEG activity and emotional responses of non‐smokers were more like those of smokers who smoked the lower‐nicotine cigarettes than those of smokers of the higher‐nicotine cigarettes.
Hostility Patterns and Cardiovascular Reactivity to Stress
Authors: Houston B. Kent , Smith Matthew A. , Cates David S.
Published: February 2007

Sixty male subjects performed two challenging tasks while systolic blood pressure, diastolic blood pressure, and heart rate were monitored. They also completed the Cook and Medley Hostility Scale and measures of social support and mode of anger expression. Subgroups of subjects who differed in the patterns of their responses to the hostility items were identified via cluster analytic techniques. Exaggerated reactivity in systolic blood pressure to the two experimental tasks was exhibited by subjects in a subgroup who appear to have negative feelings toward people, but disavow these feelings and inhibit aggression so as not to alienate others. However, these individuals may have difficulty concealing their view of others and controlling their anger which, in turn, may erode their social support.
For Distinguished Contributions to Psychophysiology: Evgeny Nikolaevich Sokolov
Authors: Graham Frances K.
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 Evgeny N. Sokolov by Frances K. Graham, on behalf of the Society's Awards Committee. Following is the text of the citation given at the meeting on October 22, 1988.
Effects of Beta‐Adrenergic Activity on T‐Wave Amplitude
Authors: Contrada Richard J. , Krantz David S. , Durel Lynn A. , Levy Linda , LaRiccia Patrick J. , Anderson Judith R. , Weiss Theodore
Published: February 2007

This study addresses the hypothesis that electrocardiographic T‐wave amplitude is influenced by beta‐adrenergic stimulation of the heart. Beta‐adrenergic activity was manipulated both pharmacologically and through behavioral challenge. Under resting conditions, 12 healthy men underwent infusion of placebo and then the beta‐agonist, isoproterenol, and the beta‐blocker, propranolol, in a counterbalanced, crossover design. During infusion of placebo, subjects also underwent two behavioral challenges, a structured interview and mental arithmetic. Analysis of the resting data indicated that propranolol produced a significant increase in T‐wave amplitude, and isoproterenol produced significant T‐wave amplitude attenuation. As previously reported, drug effects were also in evidence for heart rate. Behaviorally‐induced reduction of T‐wave amplitude was observed for mental arithmetic but not structured interview, which again paralleled heart rate data. Both pharmacological and behavioral data reported in this study support the hypothesis that the T‐wave is significantly affected by beta‐sympathetic influence on the heart. However, a nonspecific effect of heart rate change on T‐wave amplitude would also account for these results. The findings are discussed in terms of their implications for the utility of T‐wave amplitude in psychophysiological research.
Attention to Color: An Analysis of Selection, Controlled Search, and Motor Activation, Using Event‐Related Potentials
Authors: Wijers Albertus A. , Mulder Gijsbertus , Okita Tsunetaka , Mulder Lambertus J.M. , Scheffers Marten K.
Published: February 2007

In this study the organization of information processing in a selective search task was examined by analyzing event‐related potentials. This task consisted of searching for target letters in a relevant (attended) color. The ERPs revealed two different effects of attention: an early occipital negativity (± 150 ms) reflecting feature‐specific attention, and a later, central N2b component (± 240 ms) reflecting covert orienting of attention. A later, prolonged negativity (search‐related negativity) (± 300 ms), maximal at Cz, was related to controlled search to letters in the attended color. Detection of relevant targets resulted in a parietal P3b component. Depending on stimulus presentation conditions an earlier response to both attended and unattended targets was found: an N2 component (± 250 ms). In these same conditions, C3‐C4’ asymmetries (Corrected Motor Asymmetries–CMA) suggested motor activation at ± 300 ms, in the same time range as search‐related negativity. It was argued that N2 and CMA suggest the existence of a preattentive target detection system, operating in parallel with a slower serial attentive system, as reflected by N2b and search negativity.
Born of Animal Magnetism: 150 Years of Psycho‐Physiology
Authors: Tassinary Louis G. , Geen Thomas R. , Cacioppo John T. , Swartzbaugh Roger
Published: February 2007

The historical beginnings of the scientific discipline of psychophysiology are traced back to the first published English definition by Dr. Samuel Adams, M.D.
The Effect of Lateral Visual Fixation and the Direction of Eye Movements on Heartbeat Discrimination
Authors: Weisz Jüalia , Baláazs Låaszlö , Láang Eszter , ÁDám Gyöurgy
Published: February 2007

This study was undertaken to determine whether the asymmetrical activation of the two cerebral hemispheres affects the accuracy of heartbeat perception. Hemispheric preference—the tendency to activate one hemisphere rather than the other—was assessed by the directionality of conjugate lateral eye movements. Actual differential hemispheric activation was achieved by contralateral visual fixation. The results of 44 right‐handed male subjects showed that right hemisphere preferent subjects (“left‐movers”) performed better on a heartbeat discrimination task than left hemisphere preferent subjects (“right‐movers”). The direction of lateral visual fixation also influenced heartbeat discrimination: subjects fixating to the left were more accurate than those fixating to the right.
Cardiopulmonary Adjustments During Operant Heart Rate Control
Authors: Hatch John P. , Borcherding Steve , Norris Lea K.
Published: February 2007

Twenty‐three healthy men and women participated in a 5‐session experiment in which they attempted to increase and decrease their heart rate with the assistance of visual analogue biofeedback. As a group subjects did successfully raise and lower heart rate from resting baseline. These changes in heart rate were closely paralleled by changes in V̂, a measure of cardiac vagal tone. Heart rate slowing was associated with increases in V̂, and heart rate speeding was associated with decreases in V̂. Respiration rate and amplitude did not differ significantly between heart rate slowing and speeding trials, and covariance analysis indicated that respiratory changes did not account for the heart rate or V̂ effects. The weighted coherence between respiration and heart rate showed that cardiopulmonary coupling increased during heart rate slowing and decreased during heart rate speeding. Individual differences in cardiac vagal tone and cardiopulmonary coupling were unrelated to heart rate speeding and slowing performance.
The Relationship Between N2 and N400: Scalp Distribution, Stimulus Probability, and Task Relevance
Authors: Deacon Diana , Breton Françloise , Ritter Walter , Vaughan Herbert G.
Published: February 2007

The N2 and N400 components of the event‐related brain potential were compared along several dimensions. In one task, subjects discriminated on the basis of size, and in another task, subjects discriminated on the basis of semantic category. In one set of conditions stimuli deviated infrequently along one stimulus dimension (either in size or semantic category) and in another set of conditions stimuli deviated infrequently along two stimulus dimensions (both size and semantic category). When subjects discriminated on the basis of size, infrequent deviation in the size of the stimuli was associated with a negativity that peaked around 320 ms (N2). When subjects discriminated on the basis of semantic category, infrequent deviation in the semantic category of the stimuli was associated with a negativity that peaked around 400 ms (N400). N2 and N400 were found to be generally alike in scalp distribution, hemispheric asymmetry, and sensitivity to stimulus probability. N2 was not elicited when size changes were task irrelevant and N400 was not elicited when changes in semantic category were task irrelevant.
Prediction of Tonic Parasympathetic Cardiac Control Using Respiratory Sinus Arrhythmia: The Need for Respiratory Control
Authors: Grossman Paul , Karemaker John , Wieling Wouter
Published: February 2007

Respiratory sinus arrhythmia (RSA) has received much attention in recent years due to the large body of evidence indicating that variations in this phenomenon represent alterations in parasympathetic cardiac control. Although it appears that respiratory sinus arrhythmia is mediated by vagal mechanisms, the extent to which the well‐known respiratory influences (i.e., rate and tidal volume) on respiratory sinus arrhythmia (in altering its magnitude) may moderate the relationship between RSA and cardiac vagal tone has never been systematically studied.

We addressed this issue by examining intraindividual relationships among RSA magnitude, respiration (rate and tidal volume), and heart period among six healthy male adults after intravenous administration of 10 mg propranolol, a beta‐adrenergic blocker. Subjects were exposed to various behavioral tasks which altered all physiological variables measured. Variations in heart period after beta blockade were assumed to be predominantly vagally mediated. Within‐subject regression analyses consistently showed that respiratory parameters influenced RSA magnitude, but not tonic variations in beta‐blocked heart period, suggesting that respiratory‐mediated RSA alterations are not associated with changes in cardiac vagal tone. Only when respiratory variables were statistically controlled was there evidence of a reasonable correspondence between beta‐blocked heart period and RSA amplitude, providing support for the idea that respiratory parameters need to be controlled when using RSA amplitude as an index of cardiac vagal tone. Repeated‐measures analyses of variance of mean levels of heart period and respiratory sinus arrhythmia across subjects supplemented and supported the intraindividual results. These findings point to the importance of controlling for respiratory parameters when using respiratory sinus arrhythmia as a cardiac vagal index.
PRES: The Controlled Noninvasiv Stimulation of the Carotid Baroreceptors in Humans
Authors: Rau Harald , Elbert Thomas , Geiger Bertram , Lutzenberger Werner
Published: February 2007

To study physiological and psychological effects of baroreceptor activity, the cervical neck cuff technique has been frequently used to stimulate the carotid baroreceptors mechanically. Using this technique, no satisfying control conditions to date have been available.

Because the carotid stretch receptors are sensitive not only to the pressure level, but also to the rate of change, it is possible to manipulate the receptor firing through changes in carotid pulse amplitude. The device described here relies on the application of short changes in cuff pressure tied to different phases withing the cardiac cycle (phase related external suction (PRES)). A brief external suction during systole has potent stimulatory effects on baroreceptors whereas the application of the very same pressure pulse during diastole inhibits the firing burst associated with the pulse wave. To allow an ongoing period of stimulation, a sequence of alternating negative/positive pressure pulses is applied. In the stimulation condition, the R‐wave of the electrocardiogram triggers a negative pulse which is followed by a positive one during diastole. In the control condition this relationship is reversed.

Two experiments are reported confirming different baroreceptor effects of the two conditions. PRES allows for blind or double‐blind experiments to investigate effects of baroreceptor activity on physiology and behavior.
Respiratory Sinus Arrhythmia and Cardiovascular Responses to Stress
Authors: Lane James D. , Adcock R. Alison , Burnett Rachel E.
Published: February 2007

The parasympathetic nervous system provides mechanisms that could attenuate sympathetically mediated heart rate stress responses and might have even more general antagonistic actions on stress reactivity. Individuals characterized by higher levels of parasympathetic tone might, through such mechanisms, be less reactive when stimuli elicit sympathetically mediated responses. Respiratory sinus arrhythmia (RSA) is considered to be a noninvasive index of cardiac parasympathetic (vagal) tone. The present study investigated whether individual differences in RSA level at rest could predict variations among individuals in the magnitude of cardiovascular responses to psychological stress. None of the measures of resting respiratory sinus arrhythmia, derived from spectral analysis of beat‐to‐beat changes in resting heart rate, predicted the observed variations in cardiovascular task reactivity. However, scores reflecting respiratory sinus arrhythmia as the percentage of total heart rate variability (RSAnorm) were negatively correlated with blood pressure levels, both at rest and during the task. Furthermore, subjects with higher scores for RSAnorm demonstrated a faster adaptation of heart rate responses during stress, which suggests the development of parasympathetic antagonism to ongoing sympathetic arousal. Although a simple relationship between respiratory sinus arrhythmia and reactivity was not observed, these results encourage further investigation of RSA measures as psychophysiological indices of individual differences in parasympathetic (vagal) cardiac tone, or perhaps of general parasympathetic/sympathetic balance, which could modulate the expression of potentially pathogenic stress responses.