摘要:

ABSTRACTThree experiments were conducted to determine whether the external anal sphincter contraction which typically follows rectal distention is a reflex or a voluntary response. Experiment I compared 15 chronically constipated patients to 10 normal subjects. A reflex should be reliably elicited by its unconditional stimulus; but if this response is voluntary, chronically constipated patients would be less likely to show it because they have had fewer opportunities to practice it. Only half of chronically constipated patients showed the response compared to 100% of normals. Experiment II investigated whether the response is elicited by rectal distention during sleep in 10 healthy subjects. The response was significantly less likely to occur during sleep. Experiment III in 6 normal subjects revealed that this response can be voluntarily omitted. These experiments indicate that external anal sphincter contraction following rectal distention is a voluntary response, not a reflex.

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1982.tb02599.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTPreparation for a voluntary foot or finger response was studied by evoking Achilles tendon (T) reflexes. Reflexes were evoked simultaneously in both legs at 13 points between 100 and 4300 msec after the warning signal. With this paradigm, the time course of changes in reflex amplitudes related to preparatory processes could be measured simultaneously in the leg involved in the response and in the uninvolved leg. Immediately following the warning stimulus, the reflex amplitudes increased in both involved and non‐involved muscles, presumably reflecting a general non‐specific arousal. During the second half of the foreperiod, reflex amplitudes in non‐involved muscles remained elevated, perhaps reflecting a general activation of the motor system, but returned to baseline in the involved muscles. It is hypothesized that the consistently smaller reflex amplitudes in the involved leg during the entire ISI reflect a presynaptic inhibition of the la afferents to the motoneurons involved in the response. Following the response stimulus, reflex amplitudes increased in both involved and non‐involved muscles, although in the former at an earlier point and to a greater extent. It is suggested that this increase following the response stimulus is a manifestation of the transition from motor preparation to response ex

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1982.tb02600.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1982.tb02601.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTHabituation of the alpha‐blocking component of the orienting response (OR) was evaluated in depressed patients and normals. The method of feedback electroencephalography was used to elicit and control the OR.It was predicted that the depressed patients would show reduced initial ORs to visual stimuli compared to normals. The response of the patients to emotional verbal stimuli (related to their conflicts) was predicted to be more variable than the response to non‐conflict words, compared to normals.The results indicated that depressed patients are less responsive than normals for the initial few presentations of visual stimuli. The hypothesis about greater response variability by depressives to emotionally significant words was partially confirmed, i.e., the response variability was increased foroneof the two verbal stimuli. The study demonstrated that feedback EEG experiments and clinical assessments can be reliably carried out in a non‐laboratory se

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1982.tb02602.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTIn an investigation of hypotheses proposed by Lang (1977) on psychophysiological correlates of emotional imagery, 24 subjects were assigned to two equal‐sized groups. Astimulusgroup was presented, on 2 occasions, 6 image scripts, 3 of an arousing kind and 3 of a relaxing kind, in which stimulus propositions were stressed. Aresponsegroup was treated identically except that the scripts stressed response rather than stimulus propositions; further, in the response group each pair of arousing and relaxing scripts separately emphasized either cardiovascular activity, respiration or sudomotor activity, in order to assess the degree of specificity in response‐proposition relationships. Psychophysiological measures of heart rate, respiration and skin resistance, and self‐report measures of imagery vividness, general arousal, and compliance with imagery instructions were taken after each imagery trial.Analysis of the psychophysiological measures indicated that, in line with Lang's predictions, the response group showed significantly greater changes in heart rate and respiration to the arousing scenes than the stimulus group. No significant differences, however, were found for skin resistance. Moreover, there were no differences between the groups on any measures when the relaxing scenes were imagined. The groups did not differ reliably on any of the self‐report measures. Contrary to Lang's theory, however, little specificity in response‐proposition relationships was found. Rather, the present data suggest that certain psychophysiological propositions, in particular cardiovascular propositions, are generally more effective in eliciting fairly widespread psychophysiological changes. Further, a close coupling between heart rate and respiration rate was observed in this e

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1982.tb02603.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1982.tb02604.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTThis experiment investigated the effects of stimulus complexity and stimulus uncertainty on habituation of the visual orienting reaction (VOR) and the skin conductance orienting reaction (SCR) in four groups of 14 subjects each. Half the subjects were told that the same stimulus would be presented a number of times in the right upper comer of the TV screen (“certain condition”), and the other half were not informed about the stimuli (“uncertain condition”). Within each of these groups, half the subjects received 14 stimuli of 12 bits information and the other half received 14 stimuli of 60 bits information. Stimulus complexity and stimulus uncertainty led to both slower habituation of the VOR and stronger VORs on trial 1. Neither factor, howev, had a significant effect on SCR magnitude or habituation. It was concluded that the VOR and SCR represent different aspects of stimulus processing. The results of this experiment were discussed in terms of the roles which VORs and SCRs may play in selective at

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1982.tb02605.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTIt has been suggested, on the basis of phylogenetic and ontogenetic data, that the length of the REM sleep cycle is negatively related to metabolic rate. However, experimental studies have not consistently found this relationship. We report the effects of two variables, the level of physical fitness and the amount of daytime exercise, on sleep cycle length. Since both physical fitness and exercise involve increased levels of energy expenditure, and thus increased metabolic rate, it was predicted that they would he negatively related to cycle length. The sleep of 46 subjects (20 fit and 26 unfit) was assessed on nights following both exercise and non‐exercise conditions. The cycle length of fit subjects was found to be shorter than that of unfit subjects. However cycle length on a night following daytime exercise did not differ from that on a night following a no‐exercise day. We conclude that sleep cycle length is responsive to relatively long term variations in energy expenditure, but not day to day chan

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1982.tb02606.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTThe relationship between detection performance and various Event‐Related Potential (ERP) components was investigated in an auditory threshold detection task at 4 times of day (9 a.m., 1 p.m. 5 p.m., and 9 p.m.) for 7 morning‐type and 7 evening‐type subjects. Measurements were made of oral temperature, detection efficiency (P(A)), response bias(β), the N115 and the P190 components following a warning stimulus, and the P450and the Slow Wave (SW) associated with correct signal‐present decisions. For oral temperature and detection efficiency an upward diurnal trend was observed which tended to interact with subject type. For both the amplitude and the latency of the N115 and the P190 components intra‐session decrement was found. The P190 latency decreased monotonically over the day. While the diurnal trend of the amplitude and latency of the Nl15 resembled that of the SW amplitude, reaching a relative maximum in the afternoon. The P450 showed no diurnal variation. Furthermore, the P450 and SW also differed as a function of the level of decision confidence. The P450 amplitude increased and its latency decreased with an increasing confidence level, whereas the SW amplitude decreased. The diurnal variations of the N115 and the SW are discussed in terms of fluctuating amounts of processing involved in different aspects o

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1982.tb02607.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1982.tb02608.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY