ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02374.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.tb02172.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTThe ensemble averaged impedance cardiogram was evaluated during rest and during vocal mental arithmetic stress in samples of female (n=17) and male (n=40) undergraduates. Measures of myocardial performance determined from ensemble averaged signals were compared to those determined by simple beat‐to‐beat averaging over 60‐s and 20‐s sampling intervals. In addition, the influence of cardiac interval variability on dZ/dt amplitude measures was assessed. As expected, measures derived by the two averaging techniques corresponded closely, with correlations ranging fromr=0.882 tor=1.000 for the 60‐s sampling intervals, and fromr=0.726 tor=1.000 for the 20‐s sampling intervals. Inverse relationships of comparable magnitude were found between cardiac interval variability and dZ/dt amplitude measures determined by both averaging techniques, suggesting that these relationships did not result simply from artifacts introduced by the ensemble averaging technique. The results support the validity of ensemble averaging as a method for deriving impedance cardiographic measures of myocardial

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02173.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.tb02174.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTThe psychophysiological responses to laboratory stressors are often examined because it is believed that such responses relate to responsiveness in real life situations. This belief has seldom been tested. The changes in heart rate, pulse transit time, and respiration rate produced by a variety of laboratory tasks (active and passive coping and physical exercise) were related to ambulatory measures of heart rate in 32 young men. The field measures were the difference in heart rate between the waking day and when asleep, and estimates of the variability of heart rate during the day, derived from time series analyses. Average changes in heart rate and pulse transit time during specific tasks did not relate consistently to heart rate in the field. However, an active coping index, derived from the ratio of the peak heart rate during an active coping task to the peak during physical exercise related to all the field measures of heart rate responsiveness. This index, which may relate to measures of additional heart rate and heightened sympathetic response to stress, also correlated positively with Trait Anxiety and elevated basal sympathetic arousal, as measured by skin conductance level. Measures of the cardiovascular response to a passive coping task, the cold pressor, and exercise did not relate to heart rate responses in the field. The findings suggest that heightened cardiac responsiveness in real life is exhibited by subjects who show elevated peak responses to active coping stressors specifically.

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02175.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.tb02176.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTPrevious research has shown that placement of preweanling rats in an unfamiliar environment inhibits both heart rate and behavioral orienting responses to an auditory stimulus, and that the orienting response gradually reappears during the following 15 min. Four experiments designed to evaluate two potential explanations of this effect were conducted. If the arousal induced by an unfamiliar environment disrupts sensory information processing, so should the arousal induced by mild electric shock. In two experiments, the orienting response was inhibited in proportion to number of shocks received and rate of recovery was comparable to that observed in the unfamiliar environment. New environments also contain many unfamiliar stimuli which may overload the rats’ limited information processing capacity. In two experiments a change in environmental stimulation was shown to inhibit the orienting response. Recovery of the orienting response followed the same time course as that seen following shock or placement in an unfamiliar environment. Although the results of this study clearly demonstrate environmental inhibition of the orienting response, they provide little support for either the “arousal” or the “information overload” hypotheses of orienting response inhibition. The implications of these data for current theoretical conceptualizations of the orienting response are

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02177.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.tb02178.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTThis research was an attempt to replicate and extend a published study that reported a left hemispheric locus for the generation of mental images. Several methodological problems were addressed, the stability of effects was assessed by repeating the experiment, and P300 latency was measured. A lateralized visual choice reaction time task was performed twice, once without the use of imagery and once with imagery. In each visual field, the use of imagery produced a speeding of reaction times when the target stimuli matched the image generated by the subject. A similar effect was present for P300 latency, and was still present in the reaction time data after partialling out the P300 latency effect. These results indicate that mental imagery can speed both stimulus evaluation and response processing. There was no difference in the amount of speeding for images in the two hemifields, providing no evidence for a preferential locus of mental image generation in either cerebral hemisphere.

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02179.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.tb02180.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY