摘要:

ABSTRACTThe Laceys' hypothesis that baroreceptor stimulation has a direct effect on performance was tested by experimental manipulation of baroreceptor activity while subjects performed reaction time tests. Baroreceptor activity was altered by varying external cervical pressure and hence carotid sinus transmural pressure. The physiological effects of the baroreflex on heart rate and pulse transit time (a measure which generally correlates well with blood pressure) were seen both when baroreceptor stimulation was increased and when it was decreased. However, no difference in reaction time was found between the two conditions, therefore failing to support the Laceys' hypothesis.

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1984.tb00230.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTThree experiments are presented involving behavioral control of sleeping respiration during all‐night sleep recording. Probability and latency of the breathing response to an auditory signal revealed that control over sleeping respiration was obtained in all sleep stages and was maintained over several nights. This control was especially marked when failure to respond was punished (contingency procedure) by increasing the intensity of the signal (Experiments 2 and 3). Few awakenings occurred to the signal but signs of brief arousal (bursts of alpha activity, increases in EMG activity, EEG “speeding”) often accompanied the behavioral response. Overall sleep patterns were only minimally disrupted by the procedure. Demonstrating behavioral control over sleeping respiration may be a promising step toward the development of behavioral therapies for certain sleep apnea disorders and hypoventilation synd

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1984.tb00231.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1984.tb00232.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTThe purpose of this study was twofold: (a) to examine the relationship between degree of behavioral control and cardiovascular changes in 60 adult males performing an anagram solution task, and (b) to assess the interaction between behavioral control and type of subject (A vs. B). Three conditions were used, differing from each other in the percentage of solvable anagrams (100, 50, and 30%). Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were measured before, during, and after the anagram task. In all conditions, during‐task SBP, DBP, and HR were significantly elevated above baseline. Blood pressure (BP) elevations appeared to be curvilinearly related to degree of behavioral control, i.e., more elevated in the 50% than in the 100% and 30% conditions. HR changes did not differ among conditions. Concerning the Type A behavior pattern, the results revealed significantly greater BP elevations for Type A than for Type B subjects, especially in the 50% condition, thereby confirming that the physiologic correlates of Type A behavior are predominantly evoked in challenging circumstances. Findings were discussed in the light of results of cardiovascular and endocrinological research. Consideration was given to the possible role of disengagement in the 30% condition and to differences in the pattern of responding between As and B

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1984.tb00233.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTReaction time (RT), a behavioral measure of arousal, was used to examine standard criteria (Rechtschaffen&Kales, 1968) for assessing sleep onset (SO) and the sensitivity of changes in respiratory patterns at SO. Following 24 hrs without sleep, RT, respiratory, and EEG measures were used to study SO in 12 subjects. Sleep deprivation (SD) permitted multiple examinations of SO in 2 daytime testing periods. Strong relationships between RT and EEG‐based measures of SO serve to confirm the distinction between wakefulness and stage 1 sleep, and moderate to weak correlations between RT and respiratory indices describe the usefulness of the latter.Behavioral, respiratory and EEG assessments of the shift from wakefulness to sleep were observed to be orderly and rapid in these SD volunteers, suggesting that the detection of SO could be sharpened by adding behavioral and respiratory measures to the usual EEG criteria. The close temporal correspondence among these changes has interesting implications for sleep/waking mechanism

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1984.tb00234.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTThe relationships between arterial systolic and diastolic blood pressure (SBP and DBP), interbeat interval (IBI), and various pulse transit times were investigated in 5 young, healthy males during physical exercise and at rest. Transit times monitored were radial, brachial and dorsalis pedis RPIs (ECG R‐wave to pulse intervals), and brachial‐radial and radial‐dorsalis pedis PPIs (pulse to pulse intervals). Experimental sessions consisted of three periods: two involving mild dynamic exercise plus rests, and one involving static exercise (handgrips) plus rests. Correlation and regression analyses within period and subject were performed on individual beat data. Radial RPI was highly correlated with SBP (during dynamic periods, range −.57 to −.89, medianr−.81; during static periods, range −.80 to −.88, medianr=−.87) and moderately correlated with DBP (during dynamic periods, range −.10 to −.63, medianr−.52; during static periods, range −.17 to −.77, medianr−.66). Median correlations of radial RPI with SBP and DBP during exercise and rest separately were −.75 and −.40 (dynamic), −.79 and −.57 (static), and −.74 and −.26 (rest). The IBI X radial RPI product was very highly correlated with the rate‐pressure product (heart rate X SBP), an index of myocardial oxygen consumption (medianr=−.96). The only PPI which reliably indexed SBP or DBP change was brachial‐radial PPI during the

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1984.tb00235.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1984.tb00236.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTThe effects of fatigue and repetition of the task on the surface electromyographic signal were examined during 4 sessions using an isometric motor control task. The muscle chosen for this study was one of the main ankle dorsiflexors (m. tibialis anterior). The electromyographic output and a functional (force) output of this muscle were recorded during two conditions: a SHORT‐F condition in which the effect of task repetition on the relationship between force and IEMG was studied, and a LONG‐F condition in which the effect of fatigue was studied. The results indicated that repetition of the task resulted in a significant increase in the ratio between the electromyographic and functional output of the m. tibialis anterior, indicating an increase in efficiency across the 4 sessions. Fatigue on the other hand resulted in a significant decrease in the ratio between the electromyographic and functional output of the m. tibialis anterior, indicating a decrease in efficiency. Fatigue also resulted in a significant and rapid increase in the electromyographic activity. The implications of these results for the therapeutic use of the electromyographic signal were discus

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1984.tb00237.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACTOmission of a stimulus, after its regular presentation has resulted in response habituation, was observed by Sokolov to elicit an orienting response. Although noted some years ago to be crucial in differentiating competing theories of response habituation, strong support for the existence of this phenomenon is lacking in the literature. The present study examined the magnitude of the orienting response to stimulus omission as a function of sex, initial response magnitude, and habituation rate. Response magnitude was significantly greater following stimulus omission than in a control period, and this difference was independent of sex, initial response magnitude, and habituation rate. However, only 22 of the 48 subjects showed greater activity following stimulus omission than in the control period, and 9 showed the reverse. While confirming the existence of the missing‐stimulus effect, these results indicate that the phenomenon is relatively fragile when compared with expectations from a reflexive, involuntary stimulus‐comparator process as proposed by Soko

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1984.tb00238.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1984.tb00239.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY