bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extraversion and Multiple Levels of Caffeine‐Induced Arousal: Effects on Overhabituation and Dishabituation
Authors: Smith Barry D. , Wilson Raymond J. , Jones Bruce E. 
Published: February 2007

ABSTRACTPsychophysiological tests of the Eysenck hypothesis that introverts are more arousal prone than extraverts have yielded somewhat mixed results. In an attempt to clarify and extend previous findings, the present study manipulated arousal level, using caffeine. Extreme groups of 48 extraverts and 48 introverts were used, and each subject was randomly assigned to a low, medium, or high dosage of caffeine or a placebo. Each subject heard a series of tones until criterion electrodermal habituation occurred. This was followed by dishabituation, overhabituation, and a further dishabituation procedure. Increasing caffeine dosages produced a linear increment in tonic levels in extraverts, but had little effect on SCL in introverts. Higher caffeine dosages also increased phasic response amplitudes in extraverts but decreased amplitudes in introverts. Although somewhat complex, results were partially supportive of the Eysenck hypothesis.
An Arterial to Peripheral Pulse Wave Velocity Measure
Authors: Jennings J. Richard , Choi Samuel 
Published: February 2007

ABSTRACTOptical pulse transducers (photoplethysmographs) provide convenient measures of pulse wave velocity (PWV). If measured between arterial and arteriolar sites, PWV should be a sensitive index of sympathetic nervous system influences on the vasculature. Evidence of such a sensitivity was found in a study of rats in which vasoactive drug reactions simulated changes in sympathetic activity. Application of arterial to arteriolar PWV in humans further required the definition of optimal points on the two waveforms to be used in velocity calculations. An examination of different PWV indices supported use of a foot‐to‐foot index. Overall, our results support the promise of optical PWV techniques, but do not yet establish its validity as an index of peripheral sympathetic influences.
Respiration, Stress, and Cardiovascular Function
Authors: Grossman Paul 
Published: February 2007

ABSTRACTThe significance of respiratory influences upon cardiovascular functioning has been much neglected in the psychophysiological literature. Various phasic and nonphasic respiratory parameters manifest marked and specific effects upon numerous cardiac and circulatory events. Ventilatory patterns associated with stress responses, furthermore, bring about cardiovascular alterations indicative of dysfunction and risk, even when these ventilatory patterns are voluntarily enacted by normal individuals under nonstressful circumstances. Evidence is presented which suggests that respiratory processes may contribute significantly to cardiovascular competence and dysfunction. The implications of this theoretical approach for psychophysiological research are also discussed.
EEG Changes During Tobacco Withdrawal
Authors: Herning Ronald I. , Jones Reese T. , Bachman John 
Published: February 2007

ABSTRACTTobacco smoking decreases theta and alpha power and increases the dominant alpha frequency in smokers deprived of cigarettes for 10‐17 hrs. The slow alpha frequency in deprived smokers has been attributed to either (1) characterological differences between smokers and nonsmokers, or (2) nicotine withdrawal. Studies finding slower alpha in deprived smokers were not able to replicate previous findings of decreased alpha abundance after smoking, nor did they consider the importance of increased theta as a withdrawal sign. We studied 11 smokers for one day and 7 smokers for two days while they smoked a series of placebo and nicotine cigarettes. Theta and alpha power increased with tobacco deprivation but were decreased for 30‐90 min by nicotine cigarettes. The dominant alpha frequency in deprived smokers was slower than after smoking a nicotine cigarette, but the decreases in frequency were not always statistically significant.
Changes in Heart Period, Heart Period Variability, and a Spectral Analysis Estimate of Respiratory Sinus Arrhythmias During Aortic Nerve Stimulation in Rabbits
Authors: McCabe Philip M. , Yongue Brandon G. , Porges Stephen W. , Ackles Patrick K. 
Published: February 2007

ABSTRACTChanges in heart period, heart period variance (HPV), and the respiratory component of HPV were examined during enhanced negative chronotropic influences on the heart produced by aortic depressor nerve (ADN) stimulation in urethane anesthetized rabbits. Spectral analysis was used to quantify the respiratory component of HPV, respiratory sinus arrhythmia (RSA). The statistic derived from spectral analysis which describes RSA, V̂, has been proposed to be sensitive to vagal influences on the heart. Stimulation of the ADN significantly increased V̂, heart period, and HPV. However, unlike V̂ and heart period, HPV values remained elevated following the end of stimulation. Propranolol administration did not alter the magnitude of the evoked increase in V̂, heart period, or HPV. In contrast, administration of atropine abolished the increases due to stimulation in all three measures. Heart period exhibited a monotonic relationship with stimulation current intensity. This relationship disappeared after propranolol administration suggesting sympathetic mediation. The results suggest that V̂ is sensitive to manipulations of vagal influences on the heart. In addition, V̂ often responds in a different manner from heart period and HPV.
The Electrodermal Orienting Response and Memory: An Analysis of Age Differences in Picture Recall
Authors: Plouffe Louise , Stelmack Robert M. 
Published: February 2007

ABSTRACTYoung and elderly women were compared on electrodermal measures of the orienting response (OR) to picture stimuli presented during the study phase of a free recall task. Responses were also recorded during a subsequent simple habituation paradigm which was designed to investigate stimulus priming effects. Young subjects recalled more pictures than the elderly and both groups remembered more pictures with common word names than pictures with uncommon verbal labels. Young and older subjects displayed larger skin conductance responses to recalled pictures, especially to recalled uncommon pictures. Older women, however, displayed consistently smaller SCRs than the young. Stimulus priming was observed on the first trial of habituation training where not‐recalled pictures evoked smaller SCRs than pictures not shown in the study phase. There were no age differences in habituation across trials. In general, the results indicated that the electrodermal OR is functionally related to recall performance and that the age decrement in recall may be attributed to reduced cognitive effort in the elderly.
The Detection of Sleep Onset: Behavioral and Physiological Convergence
Authors: Ogilvie Robert D. , Wilkinson Robert T. 
Published: February 2007

ABSTRACTReaction time (RT), a behavioral measure of arousal, was used to examine standard criteria (Rechtschaffen & Kales, 1968) for assessing sleep onset (SO) and the sensitivity of changes in respiratory patterns at SO. Following 24 hrs without sleep, RT, respiratory, and EEG measures were used to study SO in 12 subjects. Sleep deprivation (SD) permitted multiple examinations of SO in 2 daytime testing periods. Strong relationships between RT and EEG‐based measures of SO serve to confirm the distinction between wakefulness and stage 1 sleep, and moderate to weak correlations between RT and respiratory indices describe the usefulness of the latter.Behavioral, respiratory and EEG assessments of the shift from wakefulness to sleep were observed to be orderly and rapid in these SD volunteers, suggesting that the detection of SO could be sharpened by adding behavioral and respiratory measures to the usual EEG criteria. The close temporal correspondence among these changes has interesting implications for sleep/waking mechanisms.
The Effects of Fatigue and Task Repetition on the Surface Electromyographic Signal
Authors: Mulder Theo , Hulstijn Wouter 
Published: February 2007

ABSTRACTThe effects of fatigue and repetition of the task on the surface electromyographic signal were examined during 4 sessions using an isometric motor control task. The muscle chosen for this study was one of the main ankle dorsiflexors (m. tibialis anterior). The electromyographic output and a functional (force) output of this muscle were recorded during two conditions: a SHORT‐F condition in which the effect of task repetition on the relationship between force and IEMG was studied, and a LONG‐F condition in which the effect of fatigue was studied. The results indicated that repetition of the task resulted in a significant increase in the ratio between the electromyographic and functional output of the m. tibialis anterior, indicating an increase in efficiency across the 4 sessions. Fatigue on the other hand resulted in a significant decrease in the ratio between the electromyographic and functional output of the m. tibialis anterior, indicating a decrease in efficiency. Fatigue also resulted in a significant and rapid increase in the electromyographic activity. The implications of these results for the therapeutic use of the electromyographic signal were discussed.
Laterality of 40 Hz EEG and EMG During Cognitive Performance
Authors: Loring David W. , Sheer Daniel E. 
Published: February 2007

ABSTRACTTask‐dependent lateralization of the 40 Hz EEG rhythm was investigated in 15 right‐handed male adults during the performance of verbal analogy and geometric figure rotation tasks. Forty Hz EMG recorded from the temporal and splenius muscles was similarly examined. Results indicate that 40 Hz EEG is asymmetrically distributed during cognitive performance, varying as a function of cognitive processsing. The range of laterality scores also varied by condition, with the largest variation present during baseline conditions and smallest recorded during the presentation of the verbal analogies task, suggesting that individual cognitive styles tend to vary more during less structured situations. No relationship between 40 Hz EMG and task was obtained.
Awareness of Heart Activity and Self‐Control of Heart Rate: A Failure to Replicate
Authors: Young Larry D. , Blanchard Edward B. 
Published: February 2007

ABSTRACTThe present report describes our failure to replicate a previously reported relationship between heart rate self‐control and self‐reported awareness of cardiac activity using nearly identical methods within the same population. The implications of this failure‐to‐replicate are noted.
Response Initiation, Not Completion, Seems to Alter Cardiac Cycle Length
Authors: Somsen R.J.M. , van der Molen M.W. , Jennings J.R. , Orlebeke J.F. 
Published: February 2007

ABSTRACTThe effects on cardiac interbeat interval (IBI) length of the initiation and completion of speeded motor reactions were examined at different points in the cardiac cycle (different times after the Rwave of the electrocardiogram). Stimuli were presented either at the R‐wave or 350 ms afterward. Responses were paced by instructions to release a start key prior to three different target times (150, 275, or 500 ms). Initiation time was defined as the interval between stimulus onset and the release of the start key; completion time was defined as the interval between the onset of the stimulus and the depression of one of two response keys. The shift from anticipatory deceleration to acceleration varied systematically as a function of time of response relative to the R‐wave. Responses that occurred early in the cardiac cycle were associated with a shift from deceleration to acceleration in the same IBI; for late occurring responses the shift occurred in the subsequent IBI. Most importantly, when response initiation occurred early in the cycle (<300 ms) and response completion occurred late, deceleration was terminated during the same IBI. Initiation rather than completion seems to control the inhibitory vagal input to the heart that is responsible for anticipatory deceleration.
Psychophysiological Responsiveness to Auditory Stimulation during Transcendental Meditation
Authors: Heide Frederick J. 
Published: February 2007

ABSTRACTThe Transcendental Meditation (TM) technique has been reported to produce cortical states of both steady responsiveness and lack of responsiveness to external stimulation during meditation. The present study examined alpha blocking, skin conductance, and phasic heart rate response to 80dB tones in 17 TM meditators and 17 controls. There were no significant differences between groups in rate of habituation of alpha blocking or skin conductance response, and neither group showed habituation of heart rate responding. Controls displayed a more labile and accelerative cardiac response. Results suggest the possible usefulness of cardiac waveform activity in the study of meditation.
Heart Rate and Oxygen Consumption during Active Psychological Challenge: The Effects of Level of Difficulty
Authors: Carroll Douglas , Rick Turner J. , Hellawell Jonathan C. 
Published: February 2007

ABSTRACTHeart rate and various metabolic and ventilatory indices were monitored while 24 young males engaged in two psychologically challenging tasks, mental arithmetic and Raven's matrices. Each task was structured to present subjects with three levels of difficulty: easy, hard, and impossible. Measurements were also made while subjects undertook graded isotonic exercise on a bicycle ergometer; for each subject, heart rate was plotted against oxygen consumption over the various exercise loads. Knowing oxygen consumption during the psychological tasks, these regression equations permitted the calculation of expected heart rates during each task condition, and thus the computation of ‘additional heart rate’ as the difference between actual and predicted heart rate values. Cardiac activity, whether represented as additional heart rate or as the difference between resting and task heart rate levels, was sensitive to variations in difficulty level. In both tasks the easy condition elicited significantly less cardiac activity than both the hard and the impossible conditions. Changes in oxygen consumption and carbon dioxide production did not vary significantly with difficulty. Subjects' self‐reports of active engagement and arousal paralleled the cardiac effects; in both tasks the easy condition was experienced as relatively unengaging and unarousing.
Interactions of Respiratory and Cardiovascular Adjustments to Behavioral Stressors
Authors: Allen Michael T. , Sherwood Andrew , Obrist Paul A. 
Published: February 2007

ABSTRACTThe relationships among a variety of cardiovascular and respiratory measures were examined in young college males subjected to a cold pressor task, reaction‐time shock avoidance task, and three levels of graded exercise. As expected, the relationships between cardiovascular (e.g., heart rate and cardiac output) and respiratory (e.g., oxygen uptake and minute ventilation) variables were tightly linear when considering rest and exercise values. However, the range of individual cardiopulmonary responses during cold pressor and reaction time was considerable, often leading to disruptions in the cardiovascular/respiratory interactions. Analyses of extreme high and low ventilation reactors during both reaction time and cold pressor revealed that the excessive ventilation responders in cold pressor showed clear signs of hyperventilation. Increases in ventilation by the high reactors during reaction time were of smaller magnitude than during cold pressor, with potential hyperventilation much less clear. Increases in minute ventilation by reactors during the cold pressor task were primarily due to large increases in tidal volume, with only modest increases in respiratory rate. For reaction time, however, the increases in ventilation by reactive individuals stemmed from rate increases with tidal volume remaining essentially unchanged.
Greater Resistance to Extinction of Electrodermal Responses Conditioned to Potentially Phobic CSs: A Noncognitive Process?
Authors: Dawson Michael E. , Schell Anne M. , Banis Heather Tweddle 
Published: February 2007

ABSTRACTPrevious results have suggested that electrodermal responses classically conditioned to potentially phobic CSs (e.g., pictures of snakes or spiders) are highly resistant to extinction and occur largely independently of cognitive expectancies. In order to test stringently for these possibilities, 144 college student subjects were administered differential classical conditioning acquisition and extinction paradigms while expectancies of the shock UCS were closely monitored. Half the subjects had potentially phobic CSs, whereas the other half had neutral CSs. Regardless of type of CS, during acquisition no evidence of electrodermal conditioning was found among subjects unaware of the CS−UCS contingency, nor was conditioning found on the pre‐aware trials of subjects who became aware. During extinction, there was significantly greater resistance to extinction of electrodermal responses conditioned to potentially phobic CSs as well as a similar trend with expectancies of the UCS. However, when expectancies were equated, there was no greater resistance to extinction of electrodermal responses conditioned to potentially phobic CSs. Thus, while electrodermal responses conditioned to potentially phobic CSs did exhibit greater resistance to extinction, this conditioning was no more independent of expectancies than is conditioning with neutral CSs.
Sex Differences in Physiological Reactions to Real Life Stress and Their Relationship to Psychological Variables
Authors: van Doornen Lorenz J.P. 
Published: February 2007

ABSTRACTThe present experiment investigates whether there are sex differences in physiological reactions to real life stress and whether these reactions are differentially related to psychological variables in males and females. In 29 male and 23 female students physiological measurements were taken on the day of an examination and on a normal routine day. Behavioral characteristics were measured using questionnaires. Serum cholesterol level, systolic blood pressure, and heart rate were found to be higher on the examination day. These reactions did not differ between the sexes. Males showed a larger increase of urine‐adrenaline excretion than did females. In males, cholesterol level and response were related to achievement motivation. Ambulatory monitored HR during the exam correlated with state anxiety and state depression in females, but not in males. The analysis of sex specific expression of behavioral traits in physiological parameters, including the CHD risk factors, is of potential value for a better understanding of mechanisms mediating between behavior and CHD risk.
ERPs to Laterally Presented Pictures and Words in a Semantic Categorization Task
Authors: Kok A. , Rooyakkers J. A. J. 
Published: February 2007

ABSTRACTEvent‐related potentials (ERPs) were recorded from subjects reacting to visual stimuli (pictures or words) presented in the left and right visual fields. Subjects were instructed to match these stimuli on the basis of physical or categorical identity with stimuli of a previously presented memory list. The ERPs elicited by the lateral stimuli consisted of a sequence of topographically and functionally separable, negative and positive components, including N200, P300, N540, P720, and SW. On left and right hemispheric locations N200 was consistently larger, and P720 consistently smaller to stimuli presented in the contralateral fields than to stimuli presented in the ipsilateral fields. In addition, the amplitude of P720 to ipsilaterally presented stimuli showed a marked variation in amplitude as a function of stimulus type, level of practice, and the hemispheric site of measurement, while contralaterally presented stimuli produced only minimal variation in P720 amplitude. The latter results are discussed in relation to possible intracranial sources and the functional significance of the P3 component elicited by laterally presented stimuli.
Another Look at the Relationship of Electrodermal Activity to Electrode Contact Area
Authors: Mahon Mary L. , Iacono William G. 
Published: February 2007

ABSTRACTThe present study was undertaken lo reexamine the hypothesis that the relationship between skin conductance and electrode size is monotonic and linear. Skin conductance activity was recorded from 48 right‐handed male subjects using 6 different sixes of electrode collars ranging in exposed surface area from .131 cm2 to .786 cm2. The dependent measures were skin conductance level (SCL); skin conductance response (SCR) amplitude to a series of 8 loud tones; latency, rise time, and recovery half‐time of the first tone elicited response; (he largest self‐generated SCR; and the number of nonspecific responses. The results indicated a significant linear relationship between contact area and SCL, stimulus and self‐generated SCR amplitude, and the number of nonspecific responses. Latency was not affected by electrode size although the other time‐based measures were. Differences in skin conductance activity were found among different palmar recording sites. The observed linear relationship between electrode size and electrodermal measures has implications for current models of electrodermal activity and for the comparison of results across studies in which different electrode contact areas are used.
Contrasting Effects of Response Uncertainty on the Task‐Evoked Pupillary Response and Reaction Time
Authors: Richer Francois , Beatty Jackson 
Published: February 2007

ABSTRACTThe effects of response uncertainty on pupillary and reaction time measures of processing load were compared during choice reactions. Subjects performed simple, two‐choice, and four‐choice reaction time tasks in which Go and/or NoGo responses were required, holding stimulus probability constant. In Go trials, pupillary response amplitude increased with increasing number of response alternatives, in conditions involving one, two, or four Go responses whether Go or NoGo responses were used as alternatives. The amplitude of dilations to Go responses was almost linearly related to response uncertainty, whereas the increase in response latency showed the usual decelerating function. In NoGo trials, pupillary response amplitude was also inversely related to the probability of individual Go responses. Results are interpreted in terms of a differential sensitivity of pupillary and behavioral measures to the introduction of decisional demands in the task.
Shortened REM Latency: Consequence of Psychological Strain?
Authors: Lauer C. , Riemann D. , Lund R. , Berger M. 
Published: February 2007

ABSTRACTPrevious research has demonstrated that in healthy subjects sit uat ional strain may provoke not only sleep disturbances characteristic of depression (e.g., shortened REM latencies), but also alterations in dream content. Nevertheless, there are some controversial results. The aim or our study was to clarify these inconsistencies by developing a design which might avoid some methodological problems which were present in some of these previous studies. Eleven male subjects slept in the laboratory for 7 consecutive nights. During 1 evenings they saw a stressful and a neutral movie in randomized order. The subsequent nights included REM sleep awakenings for the purpose of dream collections. Whereas the subjects were demonstrably affected by the disturbing films, the patterns of subsequent sleep remained unchanged. In contrast manifest content of the initial dreams were clearly altered. Whereas the modes of dreaming were quite different within post‐stress nights, mood was unproved the next morning in all subjects. The results are discussed within the framework of several prevailing concepts about sleep, dreams, and psychological strain.