摘要:

ABSTRACTBlood pressure and heart rate were measured in 16 borderline hypertensive and 10 normotensive subjects during mental arithmetic and reaction time tests, on standing, and during the pre‐test period and instructions preceding these tests. The reliability of responses was assessed on 3 consecutive days. Increases in systolic blood pressure and heart rate during mental arithmetic instructions, increases in systolic blood pressure during the mental arithmetic test, and increases in diastolic blood pressure on standing were greater in borderline hypertensives. These differences persisted throughout the 3 experimental sessions. Apart from stress ratings for the reaction time test, other behavioural measures, including number of mental arithmetic mistakes and reaction times, did not differ between normotensives and borderline hypertensives. The possibility that the parasympathetic nervous system exerts a restraining influence on sympathetic overactivity in borderline hypertension was discusse

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1985.tb01656.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1985.tb01657.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

ABSTRACTEyeblink performance parameters were investigated in subjects engaged in a series of duration discrimination tasks differing in modality (visual vs. auditory) and presentation schedule (fixed vs. variable). Visual tasks were associated with slower blink rates and shorter blink durations than auditory tasks. Sensitivity measures suggested that this difference might be due, in part, to the greater difficulty of the visual tasks. Blink latency declined within and across tasks and was longer for target stimuli which were followed by responses. Since the target stimuli were the short duration stimuli, the latter effect could be a compound of two opposing effects. The first is related to the response, which tends to delay the blink on target trials, while the second, related to decision processes, would tend to increase latencies on nontarget trials. Schedule of stimulus presentation did not affect dependent measures as predicted. RT was unaffected by either of the experimental variables.

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1985.tb01658.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1985.tb01659.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

ABSTRACTThis 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

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1985.tb01660.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

ABSTRACTEvent‐related potentials (ERPs) were recorded during the performance of a lexical decision task, in which a proportion of the words were either semantic associates or repetitions of the preceding word. Reaction times were faster to both the second member of associated pairs (targets) and repeated words, with the latter facilitatory effect being more than twice that of the former.ERPs to the semantic primes were more negative‐going than those to targets. This difference peaked around 400–450 ms after stimulus onset. Comparison of unrepeated and repeated words revealed a larger and temporally more extended difference, with a similar scalp topography.The prime‐target differences are interpreted as a further example of the sensitivity of the ‘N400’ component of the ERP to semantic relationships between words. The differences between the repetition and priming effects in ERPs are considered equivocal with respect to the view that the associated behavioural effects are caused by different cognitive

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1985.tb01661.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

ABSTRACTThe effects of caffeine on cardiovascular activity at rest and during psychological stress were examined in 33 healthy male college students who did not normally ingest caffeinated products. Caffeine (250 mg) and placebo were administered double‐blind in separate sessions. Heart rate, blood pressure, and forearm blood flow and vascular resistance were assessed at rest and during the stressful, competitive performance of a mental arithmetic task. Comparisons of caffeine and placebo sessions revealed that caffeine elevated resting blood pressure 4–6 mmHg, an effect which added to the elevation produced by stress. Caffeine did not affect resting forearm blood flow but potentiated the forearm blood flow response to stress and led to higher levels of flow during stress. No caffeine effects appeared in heart rate or in task performance. Family history of hypertension and Type A behavior were examined as potential modulating factors of caffeine effects but results were generally negative. These results suggest possible mechanisms through which caffeine could enhance the pathogenic effects of stress on the cardiovascular sys

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1985.tb01662.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

ABSTRACTERPs were recorded from four groups of children: reading disabled, attentional deficit disorder with and without hyperactivity, and normal controls. Subjects pressed a button to a low probability nonsense syllable (target,p= .168) and ignored all other events, which included a high probability nonsense syllable (nontarget,p= .664) and either low probability (category,p= .168) symbols (Block 1) or 3‐letter words (Block 2). The amplitudes of several late ERP components and the latency of the P3 component were examined. The overall amplitude of P3 was significantly smaller in all clinical groups than in controls, but the difference in P3 amplitude between targets and nontargets was smaller only in the two attentional deficit groups. Reading disabled children had smaller P3 and Pc components to words than to symbols, while controls had equivalent values. The N2 component had a different scalp distribution for words and symbols, but did not differentiate reading disabled children from controls. P3 latency was significantly longer in the three clinical groups than in controls, but only the attentional deficit groups showed an increase in P3 latency across blocks of the task. The results are discussed within the framework of recent cognitive models dealing with attentional processe

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1985.tb01663.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1985.tb01664.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

ABSTRACTThere is evidence that sleep is affected by physical exercise and by factors derived from exercise such as physical fitness and body composition. In this context, this study assessed the effect of type of athletic training. The sleep of four groups of 10 young male subjects, who differed with respect to the type of athletic training in which they habitually engaged, was compared on 2 consecutive, non‐exercise nights. The groups were: aerobically trained endurance runners; power trained weightlifters and bodybuilders; athletes with mixed anaerobic, aerobic, and power training; and an unfit, non‐athletic sedentary, control group. Pre‐planned comparisons showed that the control group did not differ from the combined athletic groups on any sleep variable. However, the aerobic group had more SWS and NREM sleep, slept longer, and had shorter sleep onset latencies than the power group. The mixed group was intermediate on each of these variables. The data show that the type of physical training in which athletes engage has substantial effects on their sleep–a finding which emphasizes the relevance of peripheral physiological factors for sleep architecture and which has theoretical re

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1985.tb01665.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY