bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heart Rhythm Control During Sleep
Authors: ŽEmaitytė Danguolė , Varoneckas Giedrius , Sokolov Eugene 
Published: February 2007

ABSTRACTHeart rate (HR) changes during sleep were analyzed, with the aid of a minicomputer, for a group of 20 healthy subjects. In stages 1, 2, 3, and 4, HR decreased against a background of increasing respiratory arrhythmia. REM sleep was characterized by increased HR and decreased respiratory arrhythmia. HR changes during sleep were dependent on the subject's initial autonomic HR control level. The evidence from 3 healthy subjects, who were studied under baseline conditions, propranolol (a sympatholytic agent), atropine (a parasympathetic depressant), and propranolol plus atropine, showed that the HR decrease during stages 1, 2, 3, and 4 is caused by augmented parasympathetic input. The HR increase during REM sleep is due to a reduction in parasympathetic control. The sympathetic input remains relatively constant throughout all stages of sleep, except for its decrease during stage 1.
Changes in Skin, Salivary, and Urinary pH as Indicators of Anxiety Level in Humans
Authors: Sandin Bonifacio , Chorot Paloma 
Published: February 2007

ABSTRACTIn this study, an examination was made of the levels of skin, salivary, and urinary pH associated with changes in anxiety level. Thirty‐two normal women (20–25 yrs old) were the subjects in the study. Anxiety was measured by using the Anxiety State Behavioral Scale of Chorot and Sandin, the Eight State Questionnaire of Cattell et al., a self‐report rating scale, a behavioral index (motoric expression), and the Trait Anxiety Questionnaire S‐R of Sandin and Chorot. Personality was measured by the EPI of Eysenck and Eysenck. Dependent variables were measured in three experimental conditions (Baseline I vs. Oral Examination vs. Baseline II). The results showed that: 1) During the stress condition, a highly significant increase in anxiety (A‐state) occurred. 2) During the stress situation statistically significant reductions in the skin, salivary, and urinary pH were produced. 3) There was a statistically significant correlation between the change in pH and the level of A‐state as measured during the stress period. The change in pH was greater in subjects with a high A‐state than in those having a low A‐state. In conclusion, it appears that skin, salivary, and urinary pH may serve as physiological indicators of anxiety level.
Skin Conductance Recordings and the NaCl Concentration of the Electrolyte
Authors: Hygge Staffan , Hugdahl Kenneth 
Published: February 2007

ABSTRACTThis study examined the effects of four levels of NaCl concentration (0.1–0.7%) on skin conductance responses (SCRs) and levels (SCLs) to deep breaths and loud noise. Twenty‐four subjects of both sexes took part in two identical experimental sessions, 7 days apart. All subjects encountered all four electrolyte concentrations. The results showed no effects of electrolyte concentration on SCLs or on the SCRs to the deep breaths, but indicated larger SCRs to the loud noise with the highest NaCl concentration.
Evidence of a Role for Response Plans and Self‐Monitoring in Biofeedback
Authors: Hughes Debra Ellen , Roberts Larry E. 
Published: February 2007

ABSTRACTSubjects in a control group were given feedback training for two unidentified visceral responses (increases and decreases in heart rate) and were then asked to provide a verbal report describing what they had done to control the feedback displays. Judges were given these reports and asked to determine training condition (increase heart rate on A trials and decrease heart rate on B trials, or the reverse) from them. Subjects in an experimental group received the same procedure but were also asked for a verbal report prior to receiving their first feedback display and thenceforth after each of the first 10 trials of feedback training. The results showed that: a) success at biofeedback learning is accompanied by verbal awareness of activities contributing to response production, and b) learning can be predicted (r= .80) by probing the subject's problem space before he has seen his first feedback trial. Extensive verbal probing of experimental subjects did not eventuate in superior learning in this group. The nature and role of problem‐solving activity in biofeedback are discussed.
Cognitive Distraction in Female Sexual Arousal
Authors: Adams A.E. , Haynes Stephen N. , Brayer Mary Ann 
Published: February 2007

ABSTRACTThis study was designed to assess the relationship between subjective and physiological measures of female sexual arousal during the presentation of an erotic stimulus and when an erotic stimulus was presented concurrently with a distracting stimulus. Twenty‐four females were exposed to baseline, erotic stimulus, and erotic stimulus plus distraction conditions while subjective and vaginal photoplethysmographic indices of sexual arousal were monitored. The erotic stimulus was an audiotaped description of explicit sexual activity, primarily from the perspective of a female. The cognitive distraction consisted of a series of visually presented, simple addition tasks. The results suggested significant increases in subjective and photoplethysmographic measures of sexual arousal from baseline to erotic stimulus conditions and significant decreases in both measures of sexual arousal when the distraction task was added to the erotic stimulus. Correlations between subjective and photoplethysmographic measures of sexual arousal were nonsignificant during the erotic condition, but significant when the distraction task was added to the erotic stimulus. The women were divided into “frequently” and “infrequently” orgasmic groups to further investigate the relationship between subjective and physiological measures of sexual arousal. Analyses revealed no between‐group differences in subjective or photoplethysmographic measures during any condition. Correlations between the two measures of sexual arousal were significant during all conditions for the “frequently” orgasmic groups and nonsignificant during all conditions for the “infrequently” orgasmic group.
The Effects of Practice and Task Structure on Components of the Event‐Related Brain Potential
Authors: Kramer Arthur , Schneider Walter , Fisk Arthur , Donchin Emanuel 
Published: February 2007

ABSTRACTThe present study focused on the effects of, and the interactions between, practice and task structure on human performance. The development of automatic processing through consistent stimulus‐response mapping (CM) was assessed by means of measures of reaction time and event‐related brain potentials. The subjects performed a visual search task in which they responded by pressing a button whenever a probe matched a memory set item. The variables manipulated in the study included the number of memory set items (1 or 4), the task structure (CM or VM), and the probability of occurrence of a memory set item (.2 or .8). Set size had a significant effect on RT in both CM and VM conditions prior to practice and in the VM condition following extensive practice. P300 latency mirrored RT, suggesting that the development of automatic processing substantially reduced stimulus evaluation time. The commonly observed relationship between probability and P300 amplitude, with larger P300s elicited by infrequent events, was found in the VM conditions but not in the CM condition after practice. Two different negative components were affected by stimulus mismatch. The N200 component behaved in a similar manner during automatic and controlled processing. However, a late frontally negative component was sensitive to the degree of mismatch only during controlled processing.
Evaluation of Beta‐Adrenergic Influences on Cardiovascular and Metabolic Adjustments to Physical and Psychological Stress
Authors: Sherwood Andrew , Allen Michael T. , Obrist Paul A. , Langer Alan W. 
Published: February 2007

ABSTRACTThis study was designed to examine the hypothesis that certain behavioral demands may tend to trigger sympathetic mechanisms which result in metabolically excessive cardiac output elevations. Oxygen consumption and cardiac output adjustments during a contrived reaction‐time shock‐avoidance task were compared to a cold pressor test in healthy young male adults. The linear cardiac output/oxygen consumption relationship generated by performance on a graded exercise task was used to assess the metabolic appropriateness of cardiac output adjustments to the reaction‐time task and cold pressor. The reaction‐time task was generally found to evoke metabolically excessive increases in cardiac output, while cardiac output adjustments to cold pressor were more consistent with changes in metabolic demands. However, the tasks were associated with similar heart rate responses, with a significant attenuation in stroke volume during cold pressor accounting for the differential alterations in cardiac output. This finding suggests a limited reliability for heart rate as an index of cardiac performance. The effects of propranolol, which was employed to evaluate the role of sympathetic influences, indicated that beta‐adrenergic mechanisms were responsible for mediating the cardiac output response to the reaction‐time task, but only partially contributed to the cold pressor response. Post‐hoc analyses of individual differences in cardiovascular reactivity to the reaction‐time task suggest that, for hyperreactive individuals, the coping responses evoked by this task may lead to tissue overperfusion with oxygen, thereby providing a stimulus for autoregulatory vascular reflexes which may be associated with the etiology of hypertensive disease.
Age Differences in Cardiovascular Reactivity Under Active Coping Conditions
Authors: Gintner Gary G. , Hollandsworth James G. , Intrieri Robert C. 
Published: February 2007

ABSTRACTThis study investigated whether age and parental history of hypertension were related to increases in heart rate, systolic blood pressure, and diastolic blood pressure during an active coping task. The latter consisted of a 21‐trial reaction‐time task in which electric shock and monetary incentive were contingent upon adequate performance. Subjects consisted of 60 normotensive male volunteers aged 15–55 yrs. Results showed that age yielded a significant inverse relationship with increases in heart rate, accounting for 8% of the variance. However, no age association was found for increases in either systolic or diastolic blood pressure. Subjects with a parental history of hypertension showed greater responsivity in heart rate and systolic and diastolic blood pressure than subjects without a hypertensive parent. Results are discussed in terms of methodological considerations and potential mechanisms accounting for the age‐related decline in heart rate during active coping.
Searching for the Names of Pictures: An Event‐Related Potential Study
Authors: Stuss D.T. , Picton T.W. , Cerri A.M. 
Published: February 2007

ABSTRACTThe P3 and N400 waves of the human event‐related potential were recorded during a naming task. The number of possible pictures to be named was manipulated between experimental conditions. The amplitude of the N400 was directly related to the number of pictures possible in each condition. The scalp distribution of the N400 showed an anterior negativity and a posterior positivity. This was probably the result of an overlapping P3 wave. The N400 may represent the activation of memory search and the P3 the updating of target‐expectations. Both may occur simultaneously.
Autonomic Correlates of Sensation Seeking and Monoamine Oxidase Activity: Using Confirmatory Factor Analysis on Psychophysiological Data
Authors: Zahn Theodore P. , Schooler Carmi , Murphy Dennis L. 
Published: February 2007

ABSTRACTA negative relationship between platelet monoamine oxidase (MAO) activity and Sensation Seeking (SS) has been reported in several studies. This study evaluates the possible contribution of autonomic nervous system (ANS) activity to this relationship. Additionally, confirmatory factor analysis was used to create models of ANS concepts from a larger number of psychophysiological variables. Skin conductance (SC) and heart rate (HR) were recorded from 46 men and 49 women during a two‐session protocol that included rest periods, a balloon stress, a series of tones, and two tasks: two‐flash threshold and tachistoscopic recognition. Results showed that the best‐fitting models for both rest and task periods included concepts of SC base levels (“arousal”), SC lability, and HR, and were quite similar for men and women. MAO activity correlated positively with SC concepts, most strongly for women. Women showed negative relationships between sensation seeking and both SC arousal and HR concepts. In contrast, men showed evidence of positive relationships between SC concepts and an active life style. The sex differences and response specificity in these relationships make it unlikely that ANS activity mediates the negative MAO‐SS relationship.
The Effects of Cognitive Set on the Electrodermal Orienting Response
Authors: Michihiro Kazumi , Muranaka Tetsuo , Miyata Yo 
Published: February 2007

ABSTRACTTwo experiments were designed to examine the effects of cognitive set acquired during problem solving upon the orienting skin conductance response (SCR) to a tone and its omission. Forty‐two female college students were instructed to press a key when they had found out the rule set up between the presentation of a tone and a particular digit associated with the tone.In Experiment 1, the tones were presented at every third ‘0’position, at first. After this rule was discovered, in the first group, the tone‐presentation was altered to the every third ‘7’position (Tone 0–7 Group: n=7). In the second group, the tones were not further presented after the rule was discovered (Tone 0‐No Tone Group: n=9). In the third group, the tones were continuously presented even after the subjects had found the rule (Tone 0–0 Group: n=9). Then, in the Tone 0–7 and Tone 0–0 Groups one no‐tone trial was given. The results showed that the change of tone‐rule in the Tone 0–7 Group and the tone‐omission did not evoke an orienting response. In Experiment 2, the instructions were improved so that the subjects would maintain a cognitive set to detect a possible future change in the rule. Two groups, the Tone 0–7 (n=8) and Tone 0–0 (n=9) Groups, underwent the same procedure as in Experiment 1. It was shown that the change of tone‐rule in the Tone 0–7 Group and the tone‐omission in the Tone 0–0 Group evoked the orienting response.
The Correction of EOG Artifacts by Frequency Dependent and Frequency Independent Methods
Authors: Gasser Theo , Sroka Lothar , Möcks Joachim 
Published: February 2007

ABSTRACTMethods for correcting EEG which is contaminated by EOG artifacts, which are frequency dependent or frequency independent, were compared. EEG activity contaminated mainly by eye movements was treated separately from activity contaminated mainly by blinks. The statistical comparison was based on representative, real data incorporating differential effects over frequency. The influence of EOG activity on different derivations and bands, and the resulting need for correction of EOG artifacts were of interest too. Correction using a constant gain function proved to be consistently inferior to using a gain depending on frequency. For eye movements, differences were, however, not very large in practical terms, and this was true for all frequency bands. The correction of blinks by the time domain method (i.e., constant gain) may become misleading in the sub‐delta band, which might have implications for very slow activity such as slow cortical potentials. Transfer functions not corrected for coherent EEG activity at the EOG electrodes overcompensated in the alpha and beta bands, in line with earlier results showing the need to incorporate coherent EEG activity into the determination of EOG‐EEG transfer. It was found to be preferable to use sample average coefficients and gain functions, rather than individual ones, leading also to simpler computing. EOG correction is indispensable at frontal derivations, in particular for the delta and theta bands. It is advisable to correct at central and even at parietal derivations.
Cortisol Effects on Attentional Processes in Man as Indicated by Event‐Related Potentials
Authors: Born Jan , Kern Werner , Fehm‐Wolfsdorf Gabriele , Fehm Horst L. 
Published: February 2007

ABSTRACTGlacocorticoids which are secreted from the adrenal cortex, particularly in response to stressful stimuli, are assumed to influence brain functions related to stimulus perception and processing. To determine underlying mechanisms of this action the present study investigated the effects of physiologically enhanced plasma glucocurticoid levels on auditory event‐related potentials (AERPs) reflecting different aspects of stimulus processing.Sixteen male adult subjects were tested in a dichotic listening paradigm containing four types of tone pips: standard and deviant target pips, which the subject either had to attend to, or to ignore. AERPs to the tone pips provided measures of different perceptual and attentional processes. Subjects were tested in a double‐blind fashion according to a within‐subject cross‐over design under either 16 mg hydrocortisone, infused over the experimental period of 1 hrs, or placebo.Compared to placebo sessions, under cortisol treatment a slightly decreased amplitude of the N1 component was obtained independently of the type of tone pip presented. In addition, mismatch negativity, measured as the difference amplitude between AERP waveforms to standard and deviant target pips in the unattended ear, was substantially reduced by hydrocortisone. Results support an inhibitory action of enhanced plasma cortisol levels on stimulus processing mediated by the nonspecific sensory system.
Empirical Note: Self‐Report Versus Recorded Sleep in Healthy Seniors
Authors: Hoch Carolyn C. , Reynolds Charles F. , Kupfer David J. , Berman Susan R. , Houck Patricia R. , Stack Jacqueline A. 
Published: February 2007

ABSTRACTAlthough insomnia is a major public health problem in the elderly, little information concerning the relation between subjective reports of sleep and laboratory measures in the elderly has been published. Also, while laboratory studies of the healthy elderly typically show that women steep better than men, epidemiologic studies suggest that women complain more often than men about disturbed sleep. We report here a study of 20 healthy elderly subjects without sleep complaints (10M. 10F), in which relations between subjective and objective measures of sleep were explored.Both men and women showed significant correlations between objective measures of Sleep Latency (SL) and subjective estimates of fall asleep time; similarly, in both groups, subjective estimates of sleep duration were significantly and positively correlated with Time Spent Asleep (TSA).However, in the women, but not in the men, “restlessness” of sleep was significantly correlated with WASO (wake time after sleep onset), while “soundness” of sleep was positively related to amount of slow wave sleep.In general, women showed a higher proportion of significant and more stable correlations between subjective and objective measures than did men. These findings suggest that elderly women may report sleep loss more accurately than elderly men.
The Effect of Body Position on the Perception of Cardiac Sensations: An Experiment and Theoretical Implications
Authors: Jones Gary E. , Jones Kenneth R. , Rouse Connie H. , Scott D. Michael , Caldwell John A. 
Published: February 2007

ABSTRACTThis paper presents the results of pilot data and a main experiment that examine the effect of differing body positions on an individual's awareness of heartbeats. The pilot experiment employed two groups of 12 male subjects each presented 50 Whitehead type heartbeat awareness trials in each of two body positions: seated and standing erect. Subjects were retained if their ability to discriminate on the Whitehead procedure exceeded 70% correct. Results showed that the standing body position led to significantly lower cardiac awareness than when the same subject was tested in a seated position. The pilot was then expanded and replicated with three groups of 7 male subjects, all chosen by performance on a seated discrimination series. Two of the groups made additional discriminations in either a standing or seated position. The third group remained seated in all three phases. Results showed that all three groups discriminated at significantly above chance levels during the initial screening, and the group that sat in all three phases remained much above chance. The other two groups showed significantly lower performance levels in the standing position. Order of presentation seemed to affect performance. These results almost exactly replicated the data obtained in the pilot experiment. Physiological measures showed parallel changes in heart period across phases but no indication of differences in respiration or mean arterial blood pressure. Results of a semantic differential type questionnaire used to evaluate the qualitative aspects of the feedback, and skinfold measures of body type are also reported. The results of these two experiments are analyzed for their theoretical implications which lead in two different directions. Most investigators have assumed the involvement of visceral afferent pathways in the mediation of visceral perception, and this is a clear possibility which, in large part, remains unexplored by systematic investigations. However, the results of a number of experiments are interpreted to indicate that the visceral sensations may be mediated through primary somatosensory pathways. A model for this feedback is discussed.
Are Cardiovascular Responses to Behavioral Stressors a Stable Individual Difference Variable in Childhood?
Authors: Matthews Karen A. , Rakaczky Charles J. , Stoney Catherine M. , Manuck Stephen B. 
Published: February 2007

ABSTRACTThe present paper reports two studies which address the extent to which cardiovascular responses to behavioral stress can be conceptualised as a stable individual difference variable in children. In the first study, eighth grade girls (mean age = 14.2 yrs) who had participated in a study of the familial aggregation of cardiovascular responses to behavioral stress were asked to repeat the assessment protocol when they were in (he ninth grade (mean age = 15.1 yrs). Results showed that mean task‐induced increases in diastolic blood pressure and heart rate during serial subtraction, mirror image tracing, and isometric handgrip tasks were reliable across test sessions, particularly due to the reliable increases exhibited during the mirror image tracing task. In the second study, fifth grade boys (mean age = 10.4 yrs) who had participated in a previous experiment (Matthews & Jennings, 1984) of cardiovascular responses during a video game were tested in the ninth grade (mean age ‐ 14.0 yrs) in the protocol used in Study 1. Results showed that mean tusk‐induced increases in diastolic blood pressure and heart rate during video games were related to mean task‐induced increases during serial subtraction, mirror image tracing, and isometric handgrip tasks over three years Liter. The association for heart rate increases during the video game and isometric handgrip task was particularly impressive. These results suggest that task‐induced diastolic blood pressure and heart rate responses of children are stable over substantial periods of time and amiss important developmental transitions, and generalize across tasks requiring qualitatively different behavioral responses. Nonetheless, future research is needed in adults and children to further identify factors which influence the stability and generalizability of cardiovascular responses to behavioral stress.