bluuebunny/crossref_metadata_2025 huggingface dataset:
Self‐Regulated Facial Muscle Tension Effects on Intraocular Pressure
Authors: Silvia Elvia Suyapa M. , Raczynski James M. , Kleinstein Robert N.
Published: February 2007

This study was designed to examine the relationship between orbicularis muscle tension around the eyes and fluctuations in intraocular pressure (IOP) in normal subjects. Using a biofeedback paradigm, 20 male and female subjects were asked to increase and decrease their EMG activity from the orbicularis muscle while receiving EMG feedback. Subjects received 3 alternating blocks of trials in which they attempted to increase and decrease muscle tension while maintaining the eyes open. A fourth trial consisted of a forceful closure of the eyes during the increase period. IOP was measured every 60 s throughout the entire sequence, and electrodes placed above and below the eye recorded eyeblinks. Results suggest that IOP increases with increases in facial muscle tension in normal subjects, a finding which cannot be accounted for by changes in eyeblink frequency. These results imply that increases in IOP occur during periods of increased muscle tension around the eye and suggest that muscle tension levels should be examined among individuals who have abnormally high IOP levels.
Bilaterally Synchronous Ultradian EEG Rhythms In Awake Adult Humans
Authors: Manseau Claude , Broughton Roger J.
Published: February 2007

The study documents the presence of ultradian 90‐min variations in the daytime EEG, Eight adult subjects were recorded in an isolation chamber for 8 hrs (0930‐1730). Referential frontal (F3 and F4) and parietal (P3 and P4) EEGs were obtained and frequency analyzed every 15 min for a duration of 100 s with eyes open. Behavioral and psychological data were also gathered. Spectral analyses showed the presence of significant 16 c/day (72‐120 min) rhythms at Kieitman's basic‐rest‐activity‐cycle (BRAC) rate in the overall EEG (4‐20 Hz) of each hemisphere. These electro‐cortical fluctuations were in phase between the two hemispheres. They peaked significantly only at the frontal sites. For individual EEG bandwidths, only right frontal theta showed a marked, though not statistically significant, ultradian rhythm at the 16 c/day frequency. Substantial 8 c/day peaks were also observed. Individual differences may have accounted for the observed variability of the intensity of this BRAC‐frequency rhythm. Subjects showing greater 90‐min rhythmicity in their EEG were in general less emotionally stable on the Eysenck neuroticism subscale and considered themselves as poorer sleepers. The present findings suggest that these 90‐min fluctuations may reflect periodic oscillations in the brainstem arousal system(s).
The Effects of Age on Human Event‐Related Potentials
Authors: Picton Terence W. , Stuss Donald T. , Champagne Sandra C. , Nelson Robert F.
Published: February 2007

Event‐related brain potentials were recorded from 72 normal subjects aged 20‐79 yrs. The event‐related potential to a detected improbable signal contained a large late positive component or P3 wave. The latency of the P3 wave in the response to an auditory signal increased regularly with increasing age at a rate of 1.36 ms per year, and its amplitude decreased at a rate of 0.18 μV per year. Similar age‐related changes in the P3 wave occurred in the visual and somatosensory modalities. The change in the latency of the P3 wave occurred independently of any change in the reaction time, which showed no significant age‐related change. The latency of the P3 wave associated with the detection of an omitted auditory stimulus did not change significantly with age.
Individual Differences in the Cardiac Response to High Intensity Auditory Stimulation
Authors: Eves Frank F. , Gruzelier John H.
Published: February 2007

A recently reported long latency cardiac acceleration to the initial presentation of a high intensity white noise stimulus was investigated further with pure tones. In three experiments (involving 128 subjects) marked individual differences in the secondary response were uncovered. Many subjects not showing acceleration exhibited a secondary deceleration. Subjects were categorised into Accelerators, Decelerators, and a non‐consistent‐change group on the basis of cardiac activity in a 17‐50 s poststimulus epoch. While both Accelerators and Decelerators exhibited short latency cardiac acceleration, it was of greater magnitude in the former. The long latency response is discussed with reference to a distinction between the defensive reflex and the fight/flight response. Discussion of the short latency response focuses on the startle reflex and the‘What's‐to‐be‐done?’component of the response to a novel stimulus.
Vigilance Performance and Autonomic Function in Narcolepsy: Effects of Central Stimulants
Authors: Levander Sten , Sachs Charlotte
Published: February 2007

Twenty female narcoleptic patients treated with central stimulants (CS) were studied during vigilance tests and psychophysiological recordings of autonomic functions, after 3 days off CS, and during CS treatment. Results were compared with healthy female subjects. Narcoleptics were lower in Critical Flicker Fusion (CFF), but did not differ in choice reaction time or continuous vernier visual acuity. CS improved CFF in the narcoleptic group. Narcoleptics had lower skin conductance (SC) level, but did not differ from normals in SC spontaneous fluctuations or heart rate. CS did not affect SC level or heart rate in the narcoleptic group, but counteracted the decrease in SC spontaneous fluctuations normally seen over a monotonous experimental session. CS reduced lowfrequency tremor and increased high‐frequency tremor in the narcoleptic group. Comparison with anxiety and psychosomatic patients was also performed.

The results of the vigilance tests suggested a specific disturbance of time resolution of stimulus input in narcoleptics, not related to lowered arousal, but alleviated by CS. The psychophysiological findings suggested that narcoleptic patients have a lowered habitual arousal as well as a marked tendency to decreases in phasic arousal. Central stimulants appear to improve only the latter.
Cardiopulmonary Adjustments During Exercise and an Aversive Reaction Time Task: Effects of Beta‐Adrenoceptor Blockade
Authors: Langer Alan W. , McCubbin James A. , Stoney Catherine M. , Hutcheson J. Stanford , Charlton John D. , Obrist Paul A.
Published: February 2007

The purpose of this study was to compare the cardiopulmonary and hemodynamic adjustments to a physical (bicycle exercise) and behavioral (aversive reaction time) stressor. A related aim was to assess the role of beta‐adrenergic mechanisms in mediating these physiological responses. Thirty‐four subjects were exposed to both stressors while oxygen consumption, carbon dioxide production, pulmonary ventilation, end‐tidal oxygen and carbon dioxide, as well as heart rate were calculated breath‐by‐breath. Fourteen of these subjects were pretreated with 4 mg (iv) of propranolol hydrochloride. The remaining 20 subjects (intact) were subdivided post‐hoc into the 10 most and 10 least reactive on the basis of their heart rate response to the reaction time task. The results indicate that for the intact group both exercise and the reaction time task produced significant increases in heart rate although the magnitude of the heart rate change was reliably greater during exercise. Beta‐adrenergic blockade partially diminished the tachycardia to exercise but entirely abolished the tachycardia to behavioral stress. Interestingly, the most and least reactive subjects did not exhibit differential heart rate acceleration during exercise despite a reliable difference during the reaction time task. Oxygen consumption significantly increased to predictable levels during exercise but failed to change during the reaction time task for both the most and least reactive groups. These results suggest that the tachycardia elicited by the reaction time task in reactive subjects was not associated with an appropriate increase in oxygen consumption, relative to exercise, and may therefore be indicative of systemic overperfusion.
Psychophysiological Response of Breast‐ and Bottle‐Feeding Mothers to Their Infants' Signals
Authors: Wiesenfeld Alan R. , Malatesta Carol Zander , Whitman Patricia B. , Granrose Cherlyn , Uili Robin
Published: February 2007

This study examined the relationship between infant feeding status and parity of mothers, and the psychophysiological and behavioral responses of mothers to their infants' emotional signals. Forty‐eight mothers (half breast‐feeders, half bottle‐feeders) viewed previously prepared videotaped segments of their infants' emotional expressions as heart rate, skin conductance responses, and facial expressions were monitored. Afterwards, mothers rated their subjective emotional responses to the scenes (self reports of happiness, sadness, anxiety, irritability, and helplessness) and their readiness to pick up the baby. Mothers completed an empathy measure and provided information about their choice of feeding mode and level of satisfaction with the feeding experience. The most important finding of the study was the evidence of strikingly different response patterns characterizing breast‐ and bottle‐feeding mothers across response measures. Skin conductance measures indicated that breast‐feeders may have been more relaxed under laboratory conditions than bottle‐feeders; breast‐feeders also showed a differential pattern of cardiac response to infant stimuli. On subjective measures of emotional response, the breast‐feeders were more inclined to want interaction with the infant and they also expressed greater satisfaction with the feeding experience. Response patterns were interpreted as suggesting differential physiology of the lactating mother as well as different prior personality factors operating on choice of feeding mode. A few sex of infant and maternal parity effects were observed. Empathy and facial expression measures did not differentiate feeding or parity groups.
The Standardized Mental Stress Test Protocol: Test‐Retest Reliability and Comparison with Ambulatory Blood Pressure Monitoring
Authors: McKinney Mark E. , Miner Michael H. , Rüddel Heinz , McIlvain Helen E. , Witte Hermann , Buell James C. , Eliot Robert S. , Grant Lee B.
Published: February 2007

The mental stress test protocol is used extensively in research, but different laboratories often employ different stress tasks, utilize different dependent variables to index the stress response, and perform different transformations on the gathered data. The present study determined the test‐retest reliability of 11 cardiovascular dependent variables during a resting baseline and three common stress tasks: playing a video game, performing a choice reaction‐time test, and performing a cold‐pressor test. Sixty healthy, middle‐aged males underwent testing twice, approximately three months apart. Instructions were delivered via videotape and data were gathered on‐line by computer to ensure a standard laboratory environment. Each task elicited significant increases in blood pressure, vascular rigidity, LVET, heart rate, and stroke volume. In addition, the cold‐pressor test led to increases in total systemic resistance and mean systolic ejection rate. The absolute levels of the 11 dependent variables were correlated across tasks (partialr, baseline removed, = .06 to .69, 32 of 33 comparisons significant atp<.05), indicating that reactivity to stress generalizes across alternate test forms. The absolute levels also showed significant test‐retest reliability (r= .32 to .82; 40 of 44 comparisons significant atp<.05). In addition, for 19 of 33 comparisons, absolute levels showed greater test‐retest reliability than change scores derived by subtracting the initial resting baseline value from the stress‐task value. Finally, blood pressures taken during the stress tests were more highly correlated with the average blood pressures measured via ambulatory monitoring than casual office pressures, suggesting that such stress values may more accurately reflect average blood pressure.
Association of Aerobic Fitness with Pulse Rate and Subjective Responses to Psychological Stress
Authors: Holmes David S. , Roth David L.
Published: February 2007

Ten high fit and 10 low fit subjects first sat quietly during a baseline period and then participated in a mildly stressful task (recall of digits backwards). Pulse rates and levels of subjective arousal were assessed during the baseline period and during the task performance period. Initial analyses indicated that task performance resulted in general increases in pulse rates, subjective cognitive arousal, and subjective somatic arousal. More importantly, it was found that high fit subjects evinced a smaller pulse rate increase in response to stress than did low fit subjects, but the high and low fit subjects did not differ in their subjective responses to stress. These results are consistent with a growing body of research which indicates that a high level of aerobic fitness is associated with reduced physiological reactivity to psychological stress.
Orienting, Habituation, and Short‐Term Memory
Authors: Siddle David A.T. , Kroese Biza Stenfert
Published: February 2007

Two experiments investigated the relationship between orienting activity and proactive inhibition in the Brown‐Peterson short‐term memory paradigm. In both experiments, different groups of 4 words were presented on each of 6 trials, and recall was tested on each trial following a rehearsal‐prevention period. Electrodermal activity was monitored throughout. The taxonomic category of words was the same throughout Experiment 1 (N = 96) for control groups, whereas for experimental groups, trial 5 consisted of words from a different category. In Experiment 2 (N = 96), taxonomic category was the same on all trials for all groups. However, intertrial intervals (ITIs) were either short or long, and for experimental groups, the trial 5–trial 6 ITI was either shortened or lengthened. The results of both experiments indicated that decline in recall performance across trials 1–5 was accompanied by a decrease in skin conductance response (SCR) magnitude. The change in taxonomic category in Experiment 1 produced both improved recall and increased SCR magnitude. The results of Experiment 2 indicated that both recall performance and SCR magnitude declined more slowly with long than with short ITIs. Moreover, an increase in ITI produced improved recall and increased SCR magnitude. However, although a decrease in ITI produced a decrement in recall performance, it had no effect on SCR magnitude. The results are discussed in terms of current theories of habituation and proactive inhibition in short‐term memory.
Auditory Discrimination and the Eyeblink
Authors: Bauer Lance O. , Strock Barbara D. , Goldstein Robert , Stern John A. , Walrath Larry C.
Published: February 2007

This experiment evaluated the association between blinking and cognitive activities. Subjects received 200 and 400 ms tones (1 KHz) at fixed intervals in a duration discrimination paradigm. One group (“Task”) was instructed to respond to the stimuli on the basis of duration and another (“No‐Task”) was instructed to ignore the stimuli. Blink activity (latency, rate, duration) and performance (RT, hit and false alarm rates) measures were evaluated.

A first analysis (Task subjects only) indicated that stimulus duration had significant effects on RT and blink latency; both were generally longer following the 400‐ms than the 200‐ms stimuli. In a second analysis, involving Task and No‐Task subjects, blink latencies were shorter in the Task group. Blink and eyelid closure durations increased over the task period in both analyses. These effects suggest that blinks occur when attentional processes wane.
A Comparison of the Telediagnostic and Medilog Systems for Recording Normal Sleep in the Home Environment
Authors: Sewitch Deborah E. , Kupfer David J.
Published: February 2007

Two home recording systems, the Telediagnostic (TDS) and the Medilog, were used to compare sleep in the home environment with recorded sleep from the laboratory environment in 24 normal subjects (ages 21–42). Each subject was recorded for 4 consecutive nights, 2 each in the home and laboratory environments, in a counterbalanced order. All recorded sleep was manually scored for sleep latency, sleep efficiency, sleep maintenance, sleep stage architecture, REM sleep latency, and REM sleep activity. Complete data on 10 subjects using the TDS (Experiment 1) and 10 subjects using the Medilog System (Experiment 2) were available for statistical analyses. There were no significant differences in any of the nine sleep parameters tested by recording environment or order of recording environments using the Telediagnostic or the Medilog systems. Comparing the sleep parameters recorded across experiments, subjects recorded with the TDS took longer to fall asleep in the home environment than those subjects recorded with the Medilog System. The TDS demonstrated a clear superiority over the Medilog System in its sleep monitoring feasibility and its practical and economic advantages for carrying out home sleep studies.
Parental History of Essential Hypertension, Active Coping, and Cardiovascular Reactivity
Authors: Ditto Blaine
Published: February 2007

Differences in cardiovascular reactivity to stress between individuals with and without a family history of essential hypertension (EH) may be affected by stimulus characteristics and/or individual differences in behavioral response. Twenty‐four male students with a parental history of EH and 24 without a parental history of EH participated in two laboratory sessions during which two “active’ (mental arithmetic and the Stroop word‐color interference test) stressors and one “non‐active’ (isometric hand‐grip) stressor were presented. Family history subjects exhibited greater systolic blood pressure responses than non‐family history subjects only to the two active stressors in Session 2, despite the fact that, overall, isometric hand‐grip elicited the largest responses. High‐performing Stroop subjects with a parental history of EH displayed greater heart rate responses to the task than high‐performing subjects without a parental history of EH in both sessions. No group differences appeared among poor performers. The degree to which a stressor encourages active coping behavior appears to be one determinant of differences in cardiovascular response between individuals with and without a family history of EH.
Napping versus Resting: Effects on Performance and Mood
Authors: Daiss Suzanne R. , Bertelson Amy D. , Benjamin Ludy T.
Published: February 2007

In order to determine the effects of napping and resting on mood and performance for nappers and nonnappers, 48 habitual nappers and 46 habitual nonnappers were randomly assigned to take a nap, to rest in bed without falling asleep, or to watch a neutral videotape (control group). Measurements were obtained from a 10‐min auditory reaction time task, a 10‐min addition task, and three self‐report mood measures 15 min before and after each condition. Subjects in the nap and rest conditions had electrodes attached for recording EEG, EOG, and EMG during the hour‐long treatments. Results showed that napping and resting served to improve mood regardless of whether a person habitually naps or not. Sleep itself may not be crucial in improving mood; what may be more important is the period of relaxation common to napping and resting in bed. Overall, performance measures were not affected by either napping or resting.
Small Pitch Separation and the Selective‐Attention Effect on the ERP
Authors: Alho Kimmo , Sams Mikko , Paavilainen Petri , Näätänen Risto
Published: February 2007

In conditions demanding selective attention, the stimuli to be attended elicit an event‐related brain potential (ERP) component called the processing negativity (PN). However, some previous results might be interpreted as suggesting that even the stimuli to be ignored elicit some PN, at least if they physically resemble those to be attended. This “generalization’ of PN was studied by presenting three equiprobable tones differing in pitch in random order, one of the tones at a time being the target to be counted. The small pitch separation between the three tones was of different magnitude in different blocks. A PN was observed in the ERPs to the counted stimuli but was even elicited, though with a smaller amplitude, by the nontargets, at least by those which physically resembled the targets. The latter, “generalized’ PN was larger in amplitude with a smaller pitch separation between the nontarget and target stimulus. These results support the interpretation that PN reflects a cerebral matching process between the sensory input and a voluntarily maintained neuronal representation of the stimulus to be attended, the “attentional trace.’ Moreover, these results indicate rather high discrimination accuracy of this stimulus‐selection mechanism underlying PN.
Dreamed Speech and Speech Muscle Activity
Authors: Shimizu Akira , Inoue Tsuyoshi
Published: February 2007

Polygraphic recordings were made in 20 normal adult female subjects and a total of 45 sleep records were obtained. Subjects were awakened in Stage REM or Stage 2 and, when they recalled dreaming, they were asked whether or not they had been speaking in their dreams. Polygraphic recordings enabled determination of the presence or absence of phasic EMG discharges in speech and nonspeech muscles (mimic muscle and extremity muscles) just prior to awakenings. Results were examined for correlation with presence or absence of speech recall by the subjects.

When phasic discharges occurred in speech muscles during either Stage REM or Stage 2, recall of speech in dreams was prevalent, while such recall was not observed when discharges occurred in nonspeech muscles. Moreover, recall of speech in dreams was rarely observed when no muscle phasic discharges occurred.

These results suggest that speech in dreams may be accompanied by phasic discharges of speech muscles.
Effects of a Warning Signal on Reactions to Aversive White Noise Stimulation: Does Warning “Short‐Circuit’ Habituation?
Authors: Baltissen Ruediger , Boucsein Wolfram
Published: February 2007

Reduced autonomic and subjective reactions to aversive stimuli under predictable as compared to unpredictable conditions have been explained on the one hand by the mechanism of preception and on the other hand by orienting response (OR) reinstatement in the unpredictable condition, with differences in rated aversiveness not necessarily being involved. To test differential predictions based on an habituation vs. preception position, as suggested by Lykken and Tellegen, one group of male volunteers was presented with 30 trials in which the onset time of an aversive white noise tone (110dBA) was signalled, while in the other group the onset time was not signalled. A control group received unsignalled presentations of 70dBA white noise tones. Following each trial, subjects indicated the aversiveness of the white noise at its impact. SCRs were recorded continuously. Responses produced by the signalled tones decreased over trials, while responses produced by the unsignalled 110dBA tones increased over trials. The control group exhibited a continuous decrease. Self‐report measures showed an overall decrease over trials but no differential decline. It was concluded that an OR reinstatement interpretation seems to be best in line with the data, although the observed functional significance of signalling at the autonomic level needs further evaluation to arrive at a clear distinction between OR theory and the preception hypothesis.
Different Effects of Uncertainty and Complexity on Single Trial Visual ERPs and the SCR‐OR in Non‐Signal Conditions
Authors: Verbaten M.N. , Roelofs J.W. , Sjouw W. , Slangen J.L.
Published: February 2007

Single trial event‐related potentials at Fz, CZ, P7, and OZ were measured concurrently with the skin conductance response (SCR) in a habituation paradigm. Half the subjects (26) were told that the same stimulus would be presented a number of times in the middle of a TV screen (“certain condition”), and the other half were not informed about the stimuli (“uncertain condition”). Within each of these groups, half of the subjects received 32 stimuli of 4 bits of information and the other half received 32 stimuli of 60 bits of information. No task‐relevance was given to the stimuli. Larger vertex P300 waves were associated with more complex stimuli, but uncertainty had no effect on the P300. A significant complexity × uncertainty × trials interaction was found on a sustained late positive activity, called the Slow Wave (SW), which was maximal at Pz and habituated rapidly. As before, we found that both the SCR and the vertex P300 habituated. No effect of uncertainty or complexity was found on the SCR. The results suggest that the SW is a useful index of information processing, and that the SCR and P300 must be considered to index different aspects of information processing.
Performance and Sleepiness as a Function of Frequency and Placement of Sleep Disruption
Authors: Bonnet Michael H.
Published: February 2007

Eight normal young adult sleepers spent 4 nonconsecutive weeks in the laboratory. Each week consisted of a baseline night followed by 2 consecutive nights of disrupted sleep, followed by 2 recovery nights. Disruption conditions included: a) brief awakening after each minute of accumulated sleep, b) brief awakening after each 10 min of accumulated sleep, c) 2.5 hrs of normal sleep followed by a brief awakening at each sleep onset, and d) total sleep deprivation. Morning testing revealed that all disruption conditions decreased sleep latency in a morning nap test. Performance after 1‐min disruptions approximated that seen after total sleep loss. Performance decrements were less in the 10‐min condition and least in the 2.5‐hr sleep condition. Performance under baseline and total sleep loss conditions was used to predict performance during the sleep deprivation condition using four sleep stage rules. Total time asleep and total time asleep minus stage 1 predicted performance poorly. Total SWS plus REM predicted performance best but could not differentiate the 10‐min and 2.5‐hr conditions. Therefore, it was concluded that the data were most parsimoniously explained by the Sleep Continuity Theory—i.e., that periods of uninterrupted sleep in excess of 10 min are required for sleep to be restorative.
Physiological and Subjective Sexual Arousal in Pre‐ and Postmenopausal Women and Postmenopausal Women Taking Replacement Therapy
Authors: Myers Lin S. , Morokoff Patricia J.
Published: February 2007

Twenty premenopausal, 14 postmenopausal, and 14 postmenopausal women receiving replacement estrogen therapy were studied to determine whether differences in hormone status were associated with differences in physiological and subjective sexual responses. All subjects viewed a neutral, an erotic, and a second neutral videotape while photoplethysmographic vaginal pulse amplitude was continuously recorded. Self‐report ratings of sexual arousal and affective response were collected. Serum levels of testosterone, estradiol, estrone, and luteinizing hormone were obtained. The three groups did not differ in either average or maximum vaginal pulse amplitude to the videotapes nor in latency of sexual response. The postmenopausal women not taking replacement estrogen reported significantly less vaginal lubrication in response to the erotic videotape than the higher estrogen premenopausal and replacement hormone groups. Estradiol level was significantly correlated with ratings of vaginal lubrication in response to the erotic videotape but not with vaginal pulse amplitude. Results thus suggest that estrogen is important in maintaining vaginal lubrication and the perception of sexual arousal but not in determining vaginal vasocongestion.
P300 and Recall in an Incidental Memory Paradigm
Authors: Fabiani Monica , Karis Demetrios , Donchin Emanuel
Published: February 2007

In previous research Karis, Fabiani, and Donchin (1984) found a relationship between the amplitude of the P300s elicited by words and subsequent recall performance. Words later recalled elicited larger P300s than words later not recalled. However, this relationship was dependent on the mnemonic strategies used by the subjects. There was a strong relationship between P300 amplitude and recall when rote rehearsal strategies were used, but when subjects used elaborative strategies the relationship between P300 amplitude and recall was not evident. In the present experiment we employed an incidental memory paradigm to reduce the use of rehearsal strategies. An “oddball’ task consisting of a series of names was presented, and subjects were required to count either the male or the female names. Event‐related brain potentials were recorded to the presentation of each name. Following the oddball task, subjects were asked, unexpectedly, to recall as many names as possible. The names that were recalled had elicited, on their initial presentation, larger P300s than names not recalled. Thus, these results confirm our hypothesis: when elaborative rehearsal strategies are not used, the relationship between P300 and memory emerges more consistently. Our data provide support for a “context updating’ hypothesis of the functional significance of the P300.
Predictability of Individual Differences in Activation Processes in a Field Setting Based on Laboratory Measures
Authors: Fahrenberg Jochen , Foerster Fritz , Schneider Hermann‐Josef , Müller Wolfgang , Myrtek Michael
Published: February 2007

The predictability of individual differences in activation processes was investigated in a multi‐method laboratory‐field study. Male students of physical education (N=58) were examined under various emotionally activating and physically demanding conditions (mental arithmetic, reaction time, free speech, cold pressor test, bicycle ergometer). The assessment included multi‐channel recordings of pre‐start phases in an athletic stadium and performance on a 1000 m run. Basal heart rate was also recorded during sleep. This multi‐situational assessment was repeated after three weeks, three months, and, for most (N=42) subjects, after one year. Significant relationships exist between scores from corresponding conditions of relaxation, anticipation, and performance of physical exercise. However, with the exception of heart rate, correlation coefficients are rather small and seem to be of questionable predictive validity. A generalizability study further supports the general conclusion: To increase the practical relevance in psychophysiological investigations of stress/strain phenomena, such studies should directly assess individual differences in the criterion situations themselves.
Sustained Attention in Type A and Type B Subjects: A Blink Reflex Analysis
Authors: Zelson Michael F. , Simons Robert F.
Published: February 2007

The allocation of attention by Type A/B subjects to task‐irrelevant distractors was investigated with a probe‐startle paradigm. Type A and B undergraduate students selected on the basis of their scores on the Jenkins Activity Survey worked on a series of vigilance tasks characterized by two levels of difficulty. During each task, irrelevant 50‐ms bursts of 102dB white noise were presented at approximately 35‐s intervals. Startle (eyeblink) reflex magnitude was measured during task and no‐task periods to quantify attentional allocation to the task‐irrelevant acoustic probes. As predicted, reflex attenuation was demonstrated in all subjects while attention was focused on the visual display. More importantly, Type A subjects demonstrated greater blink attenuation than Type Bs as a function of time‐on‐task. No group differences in heart rate or skin conductance response frequency were found, suggesting that A/B reflex differences were specific to attentional state and not secondary to changes in arousal.
Separability of Different Negative Components of the Event‐Related Potential Associated with Auditory Stimulus Processing
Authors: Alho K. , Paavilainen P. , Reinikainen K. , Sams M. , Näätänen R.
Published: February 2007

The lateral scalp distribution of the early negative selective‐attention effect on auditory eventrelated potentials (ERPs) was compared to the distribution of the midline‐negative N1 component inverting in polarity at the scalp area below the Sylvian fissure. No such polarity inversion was observed for the selective‐attention effect at the N1 latency. This result supports the proposal that another component, the processing negativity (PN), overlaps (summates to) the exogenous N1 in the ERPs to attended stimuli. A subsequent experiment demonstrated that the mismatch negativity (MMN: peaking at 150–200 ms), an ERP component automatically elicited by deviant stimuli presented among homogenous repetitive stimuli, had opposite polarities above and below the Sylvian fissure. Thus, the MMN at least partly emanates from a cerebral generator which considerably overlaps that of the N1. The results are discussed in terms of separability of the brain mechanisms involved in the voluntary and involuntary processing of auditory stimuli reflected by the PN and MMN, respectively.
The Effects of Caffeine and Stress on Blood Pressure in Individuals with and without a Family History of Hypertension
Authors: Greenberg Walter , Shapiro David
Published: February 2007

The effects of two doses of caffeine (125 mg, 250 mg) were compared to a placebo dose (3 mg) in a randomized double‐blind cross‐over design in 36 male caffeine users, half with and half without a family history of hypertension. Systolic blood pressure, heart rate, and respiration were recorded during rest, a mental arithmetic task, and recovery periods. I inter both resting and mental stress conditions, the two doses of caffeine on the average increased systolic pressure by 6.7 mini In compared to the placebo. The effects for the 125 me and 250 mg doses did not differ significantly. The pressor effects of caffeine and mental stress combined in an additive fashion. Systolic blood pressure levels were significantly greater in individuals with a family history of hypertension across all conditions, but not specifically in response to caffeine. The results arc comparable to those previously reported in caffeine‐naive subjects.
Gating of the Auditory Evoked Potential in Children and Adults
Authors: Freedman Robert , Adler Lawrence E. , Waldo Merilyne
Published: February 2007

Auditory evoked potentials were recorded from 163 subjects, aged IS months to 55 years. A conditioning‐testing paradigm was used to assess sensory gating. In this paradigm, click stimuli are presented in pairs to the subjects with a 0.5‐second intrapair interval. In normal adults, the first stimulus activates or “conditions” sensory gating mechanisms. The strength of these mechanisms is “tested” by the second stimulus, which produces a response whose amplitude is significantly suppressed. This aspect of sensory gating was not reliably observed in our subjects until age 18 years. Younger subjects varied widely in their ability to demonstrate sensory gating. Mean levels of suppression increased during late childhood and adolescence, with no relationship to other changes in evoked potential amplitude and latency. Sensory gating would appear to be a late developing aspect of human sensory physiology.
The Correction of Psychophysiological Measures for Individual Differences in Responsivity Should Be Based on Typical Response Parameters: A Reply to Stemmler
Authors: Ben‐Shakhar Gershon
Published: February 2007

Stemmler (1987) has criticized conclusions drawn from a previous article (Ben‐Shakhar, 1985) which compared several transformations of raw SCRs lo correct for individual differences in responsivity. Stemmler claims that within subject standardization is biased because it utilizes within‐subjects standard deviations based on individual subjects' entire response distributions. 1 agree with Stemmler that it may be preferable to use modified z‐scores based solely on within stimulus‐set variability. However, 1 claim that the general conclusion drawn from my demonstrations‐namely, that any correcting formula should be based upon parameters that represent the subject's typical response level, rather than maximal response level‐is valid. This conclusion was based not just on the advantage of z‐scores over paintal scores, but also on an extensive analysis that compared other transformations which were based either on individual subjects' mean SCR or on maximal SCR, These transformations did not utilize the standard deviation parameter and are therefore free from all the problems mentioned by Stemmler.
Family History of Hypertension and Cardiovascular Responses to Orthostatic Stress
Authors: Weipert Doris , Shapiro David , Suter Thomas
Published: February 2007

Cardiovascular effects of orthostatic stress (sitting to standing) were assessed in 60 healthy young male subjects according lo family history of hypertension (half with a positive and half with a negative family history' of hypertension). Systolic (SBP) and diastolic blood pressure (DBF) were recorded on each successive heart heal using a non‐invasive blood pressure tracking system. Heart rate (HR) and respiration rate (RR) were also recorded. During the postural change, characteristic phasic changes were shown with an initial fall and subsequent recover of SBP and DBF and a mirror image response in MR and RR. Phasic analysis of the pre‐standing sit, peak/trough, and recovery stand values indicated group differences in the initial as well as the later phases of orthostatic response. In the initial phase, subjects with a positive family history of hypertension showed an earlier trough in systolic and pulse pressure and an earlier peak in heart rate response immediately on standing up. The level of the pulse pressure trough was also higher in these subjects. In the later standing phase, these subjects showed higher levels of pulse pressure. The results were interpreted in terms of increased sympathetic nervous system activity during the initial phase and structural and neurocirculatory abnormalities in the later phase of orthostatic regulation in individuals with a positive family history of hypertension.
Event‐Related Desynchronization and P300
Authors: Sergeant Joseph , Geuze Reint , van Winsum Wim
Published: February 2007

The information processing demands of frame time, cognitive load, and event rate were examined with respect to the duration and amplitude of the event‐related desynchronization (ERD) and the event‐related potential P300. The central question was: are ERD and P300 cortical indices of the same attentional processes or resources? It was found that ERD amplitude became larger and P300 amplitude smaller with a larger load and a slow event rate, independently. ERD duration and P300 latency became longer with a slow event rate and a higher processing load. For ERD duration these effects were additive, for P300 latency they were interactive. Frame time influenced only P300 latency, which became longer with a long frame lime. The results are discussed in relation to a taxonomy of task variables.
Is Mediation of Sweating Cholinergic, Adrenergic, or Both? A Comment on the Literature
Authors: Shields Stephanie A. , MacDowell Kathleen A. , Fairchild Sarah B. , Campbell Mary L.
Published: February 2007

Research on SNS mediation of human eccrine and apocrine sweating was examined. Both types of sweat glands in humans are innervated primarily by cholinergic fibers and, at least sparsely, by adrenergic fibers. Both types of sweat glands are also stimulated by circulating catecholamines, but the mechanism for this action has not been unequivocally established. Recent research developments in the physiology of the sweat glands are discussed as they bear on persistent problems in psycho physiological research.
Blink Reflex Magnitude During the Foreperiod of a Warned Reaction Time Task: Effects of Precueing
Authors: Boelhouwer A.J.W. , Bruggemans E. , Brunia C.H.M.
Published: February 2007

In a warned reaction time task blink reflexes were evoked electrically at different points in time during a 3‐s foreperiod between the warning signal (WS) and the response signal (RS;. Two groups of 16 well‐trained right‐handed subjects participated. One group was informed by the warning signal as to whether or not a voluntary blink response was to be given following the response signal. For the other group of subjects, response‐relevant information was delivered by the response signal. Reaction times were shorter when subjects were precued by the warning signal, which indicates a more efficient preparation in this condition. In the blink reflex an early ipsilateral component (R1) and a late bilateral component (R2) could be distinguished. Within 300 ms after the warning signal, an increase in R1 was seen which was more pronounced when the warning signal precued the required response. R2 was inhibited shortly after the warning signal. At the end of the foreperiod R1 increased more and R2 was more inhibited the higher the response certainty. The general conclusion is that the presentation of a warning stimulus has a facilitatory effect on R1 and an inhibitory effect on R2. A warning stimulus with more information results in an extra increase in R1 magnitude only, while preparation for a response is seen in both R1 and R2 magnitudes.
Evaluation of Myocardial and Peripheral Vascular Responses During Reaction Time, Mental Arithmetic, and Cold Pressor Tasks
Authors: Allen Michael T. , Obrist Paul A. , Sherwood Andrew , Growell Michael D.
Published: February 2007

The primary purpose of this study was to examine the covariation of cardiac output and forearm blood flow during reaction time, mental arithmetic, and cold pressor tasks. Cardiac output was indexed using impedance cardiography, whereas impedance venous occlusion plethysmography was used lo index forearm blood flow. Cardiac output increased significantly over resting values in all three tasks, hut the pattern of these increases differed. Large heart rate increases during mental arithmetic and cold pressor tasks more than offset stroke volume decreases; the increases in the reaction time task were due to relatively smaller heart rate increases with stroke volume augmentation. For forearm blood flow, all task levels were higher than resting levels, but only mental arithmetic levels were statistically higher. The correlation between cardiac output and forearm blood flow change was significant for the reaction time task, but not for the mental arithmetic or cold pressor tasks.
Bilateral Finger Temperature and The Law of Initial Values
Authors: Jamieson John
Published: February 2007

Twenty‐two male and 43 female right‐handed subjects engaged in three different cognitive tasks while finger temperature was recorded bilaterally. The tasks, presented in randomized order, were: counting backwards by 17's, the Stroop task (Stroop, 1935). and a spatial task. All tasks produced significant (p < .001) temperature decreases on both sides of the body. Relative changes in left‐right temperature did not differ significantly among tasks, indicating no task related asymmetries. The right hand decreased in temperature significantly more than The left hand to two of the three tasks, but it is argued that this difference reflects the Law of Initial Values, not differential hemispheric involvement. The Law of Initial Values is shown to hold for finger temperature, contrary to an earlier report. Additionally, left‐right temperature differences are shown to reflect the law of Initial Values.
Cooperative Dyadic Interactions, Perceived Control, and Task Difficulty in Type A and Type B Individuals: A Cardiovascular Study
Authors: Abbott Jantce , Sutherland Colin , Watt Douglas
Published: February 2007

Eighty Type A and SO Type B young male subjects (assessed by both the Bortner and Thurstone Scales) cooperated on either a difficult or simple reaction time task, with either the same or opposite behavior type partner. Only the first member of each dyad was given control of responding A‐A, B‐B, A‐B, B‐A). Dyads performed with equal efficiency on the simple task, but when the task became more difficult to master a remarkable pattern of behavioral activity emerged. Deleterious or efficient task performance was largely influenced by the behavioral style of the two individuals within the dyad, and more importantly, by their control positions (which member had response control). Cardiovascular responses were monitored throughout the task and 10 min following task performance. During the task, increases in heart rate, and systolic and diastolic blood pressure were observed for all groups regardless of task difficulty and control positions, although the magnitude of cardiovascular reactivity was greatest for Type As during the difficult task, especially if they lacked control of responding or were cooperating with the same type partner. Following the difficult task, Type As demonstrated greater magnitude and more prolonged cardiovascular reactivity, compared with Type Bs. The findings are briefly discussed within the context of the work environment.
Individual Differences in Stages 3 and 4 Sleep
Authors: Bliwise Donald L. , Bergmann Bernard M.
Published: February 2007

Individual differences in stages 3 and 4 sleep are usually unrecognized., although several reports have mentioned large inter‐individual variation of the stages within a restricted age range. This study investigated individual differences and nightly reliability in stages 3 and 4 sleep in a homogeneous sample of 34 young adult males. Sleep was analyzed from the final two of three consecutive lab nights. Results indicated that stage 4 steep was an exceedingly prominent individual difference. Stage 4 occupied 7.9 to 50.0 percent of the first 3 hrs after sleep onset and was highly reliable across nights (.78). Individual differences were less pronounced in the second 3 hrs after sleep onset. Stage 3 and stage 4 were reliably distinguished. Persons high in one of these stages had relatively little of the other. Combining stage 3 and stage 4 may be a reasonable strategy if visually scored delta activity per se is of interest, bat it may obscure potentially meaningful individual differences in which state is characteristically achieved.
Comparison of Discrete Cardiovascular Fitness Groups on Plasma Catecholamine and Selected Behavioral Responses to Psychological Stress
Authors: Sothmann Mark S. , Horn Thelma S. , Hart Barbara A. , Gustafson Anthony B.
Published: February 2007

Discrete cardiovascular fitness groups consisting of high‐fit (n=10) and low‐fit (n=9) men performed a well‐learned vigilance task and their self‐report, performance, and plasma catecholamine responses were compared. No significant differences were observed between the fitness groups on self‐report or psychomotor performance responses to the vigilance task. However, the low‐fit group took significantly longer than high‐fit subjects to complete the first of three sets of anagrams administered immediately after the vigilance task. Plasma norepinephrine but not epinephrine response was greater in the low‐fit group compared to their high‐fit counterparts. The findings indicate that enhanced cardiovascular fitness may be characterized by an attenuated plasma norepinephrine response to a vigilance task with sustained cognitive performance subsequent to the task.