摘要:

ABSTRACTThe purpose of this study was to evaluate the influence of the normal menstrual cycle on lipoprotein, cardiovascular, and neuroendocrine stress responses. Fifteen normally‐cycling, healthy women participated in a series of behavioral tasks during the menstrual, follicular, and luteal phases of their menstrual cycle. These women had established menstrual cycle regularity for the three months prior to enrollment in this study, were free from menstrual cycle disturbances, biochemically confirmed that they ovulated, and displayed appropriate patterns of reproductive hormone fluctuations during the study period. Heart rate, blood pressure, low density lipoprotein‐cholesterol, and total cholesterol all demonstrated significant elevations from baseline levels during tasks. No differences in the magnitude of stress responses during the three menstrual cycle phases were noted for any physiological variable. We conclude that the hormonal fluctuations that occur in healthy, normally‐cycling women during the menstrual cycle do not influence the stress responses that were investigated here. Significant influences of menstrual cycle phase previously reported in the literature, albeit not in a consistent direction, may have been due to the recruitment of women with menstrual cycle irregularities, and to the failure to adequately verify menstrual cycle

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb00364.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTEvent‐related brain potentials (ERPs) were recorded from 28 young adult subjects during a continuous recognition memory paradigm, with pictures as stimuli. Subjects were required to determine on each trial if the picture was “new’ (never before presented) or “old’ (seen previously). To assess differences between primary and secondary memory. old items were presented after lags of 2, 8, and 32 intervening pictures (equiprobable) following their first presentation. The results suggested that a negativity (Czmaximum) at 300 ms was the most likely candidate for the brain event reflecting the retrieval of the item from memory. Old/new effects were modulated by two types of activity. both of which were larger in the ERPs elicited by new items. The earlier of these, possibly similar to the N400, had a duration from about 250‐600 ms, began with the N300 deflection, and lasted until “P300′’began to decrement. The other was positive, resembled “positive slow wave,’onset as P300 began to decrement, and lasted until the end of the recording epoch. There were no consistent effects of item lag on the behavioral data or on any of the ERP components. suggesting that for pictorial stimuli, the distinction between the two types of memory store, primary (i.e., immediate memory) and secondary (newly learned information), may not be relevant. In consonance with the lack of lag effects, it was suggested that the lack of a robust subsequent memory effect on the ERP waveform could have been due to the use of pictures, which may have required less elaborative processing in order t

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb00365.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTHeart rate, systolic and diastolic blood pressure, and respiratory and metabolic activity were recorded prior to and during mental arithmetic and a video game task in 20 young men with mildly elevated casual systolic blood pressures. Twenty‐five unambiguously normotensive young men were tested under the same protocol. For pretask baseline physiological activity, group differences emerged for all cardiovascular and metabolic variables; thus the elevated blood pressure group displayed not only higher resting cardiovascular levels than normotensive subjects, but higher levels of metabolic activity too. With regard to change in physiological activity from rest to task, the group with mildly elevated blood pressure showed reliably larger increases in heart rate to the mental arithmetic task than the normotensive subjects. These effects, however, were not paralleled by group differences in metabolic activity increase. Physiological measures were also taken prior to and during graded dynamic exercise. The subsequent calculation of individual heart rate‐oxygen consumption exercise regression lines allowed the comparison of actual and predicted heart rates during psychological challenge. The subjects with mildly elevated blood pressure displayed significantly greater discrepancies between actual and predicted heart rate values than normotensives during the psychological tasks in general and menta1arithmetic in particular. Group differences in physiological activity during exercise largely reflected the pattern seen at rest. A possible exception here was systolic blood pressure. Not only were systolic blood pressure levels higher throughout the exercise phase for mildly elevated blood pressure subjects, but this group evidenced more of an increase from rest to exercise than the normotensi

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb00366.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTThis experiment investigated how the P3a, P3b, and Slow Wave components of the event‐related brain potential (ERP) respond to manipulations of the nature, timing, and extent of information delivery. There were two experiments in which the total amount of task information was distributed between pairs of successive stimuli (S1and S2) within each trial. The task was to predict the relation between S1and S2. In Experiment 1, the S1could resolve no, partial, or all uncertainty with respect to the prediction outcome (correct or incorrect). Each S1delivered three types of information: 1) outcome information–which resolved the subjects' uncertainty about the correctness of their prediction: 2) procedural information–which resolved uncertainty about how much outcome information would be delivered by S1; and3) memory information–the identity of S1, which had to be stored for subsequent comparison with S2. In Experiment 2, the activity of these components was contrasted in two conditions in which the S1delivered either memory information alone or both memory and procedural information. P3a and Slow Wave were sensitive only to outcome information. P3b was sensitive to all three types of information, and its scalp topography varied as a function of the type of information. The topographic variations indicate that P3b is not a unitary phenomenon but rather is a composite of activity arising from multiple intracranial sources of bioelectric a

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb00367.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTComplex social factors can influence physiological activity, behavior, and health, but little is known about how essential components of these factors (e.g., human association, observation) affect human physiology. To begin to address this issue, an experiment was conducted to contrast predictions from social facilitation, distraction/conflict, and physiological reactivity formulations regarding the physiological effects ofmere observation.Skin conductance and heart rate were measured surreptitiously from 27 women during a period in which they believed that the experimenter was simply calibrating auditory and physiological recording equipment. Approximately half of the subjects were led to believe that they could be observed by the experimenter during this period, and the remainder were led to believe that they could not be observed. Following baseline recordings, a series of 10 orienting tones were presented. Predictions from the physiological reactivity formulation were supported: (a) no differences in basal levels of somatovisceral activity were found as a function of mere observation; (b) mere observation enhanced the skin conductance response to the initial orienting tone; and (c) these physiological differences were punctate, quickly dissipating and quickly habituating. Hence, mere observation has subtler physiological effects than thought previously. Implications are discussed regarding the possible mechanism underlying the stress‐enhancing and stress‐buffering effects of human association, and regarding the effects social and contextual factors may have in psychophysiological research. Results from an international survey, based on the responses of 57 authors of articles that have appeared inPsychophysiologysince 1983. are reported to inform the latter discussion. Results suggest that, even when social factors in psychophysiological research are minimized or held constant within studies, subtle differences in the social context across studies within and across laboratories may contribute to the appearance that psychophysiological relationships are unrelia

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb00368.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTTo assess the contribution of the heart's autonomic innervation to reactivity to psychological stressors, hemodynamic responsiveness of the denervated human heart was examined in two studies. In Study 1, cardiac output measured by thermodilution. heart rate, and systolic and diastolic blood pressure responses to a 4‐min mental arithmetic task were studied in 7 cardiac transplant patients during routine post‐transplant cardiac catheterization. In Study II, 6 cardiac transplant patients, 5 normal controls, and 5 renal transplant patients participated in a 78‐min psychophysiological stress protocol during which heart rate, systolic and diastolic pressure, and cardiac output (measured noninvasively by impedance cardiography) as well as serum epinephrine and norepinephrine were measured at baseline and while subjects performed mental arithmetic and reaction time tasks.In Study I, transplant patients showed significant increases, relative to baseline, in heart rate, systolic blood pressure, and cardiac output in response to mental arithmetic. The diastolic blood pressure response was marginally significant. In Study II, mental arithmetic produced significant reactivity in systolic blood pressure and marginally significant increases in heart rate and diastolic blood pressure in cardiac transplant patients. Reaction time produced only marginally significant diastolic blood pressure reactivity. Hemodynamic reactivity of the cardiac transplant group generally was lower than that of the two innervated groups, which generally were similar to each other.Although the small number of subjects makes conclusions tentative, these data suggest that: 1) Cardiac transplant patients are capable of significant reactivity to psychological stressors despite the absence of innervation of the heart, and 2) reactivity to these stressors is diminished relative to innervated control subjects. In the absence of cardiac innervation, reactivity is due to the vascular system and cardiac effects mediated by humoral fa

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb00369.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTShort latency evoked potentials were recorded during a cross‐modal selective attention task to evaluate recent proposals that sensory transmission in the peripheral auditory and visual pathways can be modified selectively by centrifugal mechanisms in humans. Twenty young adult subjects attended in turn to either left‐ear tones or right‐field flashes presented in a randomized sequence, in order to detect infrequent, lower‐intensity targets. Attention‐related enhancement of longer‐latency components, including the visual P105 and the auditory N1/Nd waves and T‐complex, showed that subjects were able to adopt a selective sensory set toward either modality. Neither the auditory evoked brainstem potentials nor the early visual components (electroretinogram, occipito‐temporal N40, P50, N70 waves) were significantly affected by attention. Measures of retinal B‐waves were significantly reduced in amplitude when attention was directed to the flashes, but concurrent recordings of eyelid electromyographic activity and the electro‐oculogram indicated that this effect may have resulted from contamination of the retinal recordings by blink microreflex activity. A trend toward greater positivity in the 15–50 ms latency range for auditory evoked potentials to attended tones was observed. These results provide further evidence that the earliest levels of sensory transmission are unaffected by cross‐modal selective attention, but that longer latency exogenous and endogenous potentials are enhanced to stimuli i

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb00370.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb00371.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTAuditory event‐related potentials (ERPs) from a multidimensional selective attention task were recorded from 10 unmedicated schizophrenic patients and 10 age‐ and sex‐matched healthy controls. Tone pip stimuli varying on the dimensions of pitch (high or low) and location (left or right ear) formed four ‘channels’ of stimuli: left low, left high, right low, and right high. The pitch difference was considerably more difficult to discriminate than the location difference. Subjects were instructed to pay attention to a designated channel and press a button whenever they detected a long‐duration, rare target tone that occurred amongst frequent short‐duration standard tones. There were a number of differences between unmedicated schizophrenics and controls in processing negativity elicited by standard tones. There was no evidence of hierarchical processing of stimulus dimensions in the early processing negativity component, and the late frontal component was virtually absent in schizophrenics. Furthermore, there was evidence that in schizophrenics the processing of the location dimension was delayed for standard tones having the same pitch as the target. The P300 component to attended target tones was substantially reduced in schizophrenics over parietal sites but there was no difference between the two groups over frontal sites. The results are interpreted in terms of multiple attentional deficits in schizophrenics that are indicative of a failure in the planning and execution of selective listening strategies. Such a failure may result from a dysfunction in the prefrontal regions

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb00372.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb00373.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY