摘要:

ABSTRACTSeveral sets of data illustrating dissociation of metabolic and muscular work rates are presented. During response acquisition, the rate of energy expenditure declines although work rates remain constant and goal achievement increases. When higher response costs are demanded for goal achievement, work rates increase whereas energy expenditure remains constant. Decreases in outcome probability also give rise to increases in motor intensity and work rate but do not influence the rate of energy expenditure. It is proposed that behaviourally‐related variations in metabolic rate are influenced by environmental uncertainty (“what to do”), whereas variations in the intensity of motor output are influenced by response uncertainty (“how to do it”). The processes of response selection which provide the means by which response uncertainty is resolved, activate motor channels for the expression of energy mobilized by the prevailing state of environmental un

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1987.tb00326.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1987.tb00327.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTTwenty‐nine dyslexic children (mean age 10 yrs) were randomly assigned to piracetam (3.3 gr/d) or matching placebo in a 36‐week double‐Mind study. Event‐related potentials (ERPs) were obtained at the end of treatment from a vigilance paradigm which required a response to letter‐matches or form‐matches. The drug group showed a significant advantage in letter‐bits compared with placebo, and a reduced variance in reaction time. The drug increased the amplitude of three factors from a principal components analysis of ERPs, and was interpreted as increasing a processing negativity when stimuli were letters. Effects upon the prestimulus baseline for letter‐hits were interpreted as faster termination of a CNV under drug for letter‐pairs. Latency of early N100 components were faster under drug, suggesting improved feature analysis. It is concluded that piracetam enhances feature analysis and increases attentional resources among dyslexics when the stimuli are recognized as having lingui

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1987.tb00328.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1987.tb00329.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTSkin conductance was examined in patients with Huntington's disease (HD) and progeny at risk for HD to determine if electrodermal characteristics had potential to identify those progeny likely to succumb to HD. The two experimental groups chosen for study consisted of 7 patients in the early stages of HD and 29 progeny of HD patients. Because the HD and at‐risk groups differed in age and sexual composition, each was matched by age and sex to separate psychiatrically and medically healthy normal control samples. Skin conductance was recorded bilaterally while subjects listened to three series of stimuli: 8 85dB tones, 12 105dB tones, and two familiar sounds. Dependent measures included skin conductance level, number of nonspecific responses, number of responses elicited by each tone series and the sounds, the amplitude, latency, rise time, and half‐recovery rime of the first tone‐elicited response in each series, and habituation rate to the soft and loud tones. The data analysis was carried out by comparing each experimental group to its matched comparison sample. A variety of parametric and nonparametric tests were carried out; no significant differences emerged either between the HD patients and their control group or between the at‐risk subjects and their normal comparison group. Ninety‐seven percent and 86% of the at‐risk and HD subjects, respectively, responded at least once to the experimental stimuli, compared to 90% and 86% of the corresponding con

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1987.tb00330.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1987.tb00331.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTThe effects of two levels of sleep fragmentation on sleep and daytime sleepiness were investigated in young adult males. Experimental subjects were informed while awake that tones would be presented periodically throughout the night and that their task was to terminate the tone by taking a deep breath. Eight subjects received tones after each minute of sleep and 8 received tones after each 4 min of sleep. Control subjects (N=8) HI did not receive (ones. The subjects were tested for daytime sleepiness using the Multiple Steep latency Test. It was found that: 1) subjects responded reliably lo tones presented during sleep; 2) behavioral control was accompanied by brief electro‐physiological indices of arousal on almost all trials, and occasionally led to fall awakenings; 3) sleep was markedly altered in the 1‐min condition; 4) a relatively small effect on sleep (reduced stage 4 sleep) was produced by the 4‐min condition, and 5) daytime sleepiness was increased by the 1‐min condition but not the 4‐min condition. It was concluded that the most parsimonious explanation of these results is (he Continuity of Sleep h

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1987.tb00332.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1987.tb00333.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTTwo experiments are presented concerning the control of learned behavior by stimuli presented during sleep. The rule of associative and nonassociative factors was assessed in Experiment 1. Group I was tested to demonstrate that, following instructions during wakefulness, subjects would terminate tones presented during sleep by taking a deep breath. To determine the likelihood of spontaneous responses during the tone, two groups were tested following the same instructions but with tones omitted on every trial (Group II) or every other trial (Group III). To determine whether breathing responses might be due to tone‐elicited arousal. Group IV was tested without instructions to make the breathing response. Reliable responding was found only for Group I. Experiment 2 concerned within‐ and across‐night patterns of responsiveness under the procedure investigated in Experiment 1. Subjects were tested for either 4 consecutive or 4 nonconsecutive nights. Response latencies increased within nights and also across nights with a greater rate of increase on consecutive nights. The data are discussed in relation to the importance of understanding the effects of behavioral demands during

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1987.tb00334.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

ABSTRACTData were obtained from elite rifle marksmen during baseline and performance conditions (prior to trigger pull) to examine electroencephalographic (EEC) alpha and heart rate (Ilk) patterning. The results were discussed in terms of “response intention” because a trend was found in HR patterning during performance which paralleled that associated with Laceys' (1970) work on selfpaced “key pressing.” Additionally, directional fractionation of the arousal response was evidenced by an increase in tonic MR from baseline to performance which was accompanied by an absence of change in EECJ, Finally, regression analyses revealed a differential relationship of temporal EEC with HR. Specifically, a cardiac “sensitivity” of the right hemisphere was shown by an association between HR and subsequent EEG during the final phase of the marksman's preparatory state. Occipital EEC also appeared to be influenced by cardiovascular activity. These findings extend the generality of the fractionated arousal construct to an intentional and well‐learned motor skill paradigm and question the generality of the act

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1987.tb00335.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY