摘要:

ABSTRACTEvent‐related potentials were recorded from subjects who listened selectively to stimuli in one of two input channels (ears). The stimuli were random sequences of five vowels and a tone pip. In separate experimental runs, the difficulty of within‐channel selection was manipulated by designating either tone (T), one vowel (1V), or two vowels (2V) as targets. An attention‐related negativity (Nd) was observed for attended nontarget vowels irrespective of the target difficulty, but the early, centrally maximal phase of Nd was substantial only for the one‐vowel and two‐vowel conditions. The Nd between its early and late peaks was significantly larger for the two‐vowel condition than for the one‐vowel and tone conditions. The 2V minus 1V difference in Nd had a closely similar distribution to the early Nd. These target difficulty effects were interpreted as suggesting that the early Nd recorded in two‐selection tasks can be related to a within‐channel selection process as well as a between‐channel selection process. The more anteriorly distributed, later phase of Nd was suggested to be rather insensitive to the difficulty of the within‐channel selection. The nature of the within‐channel selection underlying the early Nd was discussed in relation to controlled m

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1989.tb03143.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1989.tb03144.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTThis paper describes a method of measuring baroreceptor cardiac reflex sensitivity noninvasively from spontaneous patterns of blood pressure and interbeat interval, and the application of this technique in psychophysiology. Baroreflex function was assessed in 24 female volunteers during relaxation and performance of the cold pressor test and a non‐verbal mental arithmetic task. Blood pressure and interbeat interval were monitored continuously from the finger using the vascular unloading technique. Sequences of three or more cardiac cycles were identified over which systolic blood pressure increased progressively in conjunction with lengthening interbeat interval, or systolic blood pressure decreased as interbeat interval was reduced. The regression between systolic blood pressure and interbeat interval was computed as an index of baroreflex sensitivity. Relaxation was associated with a small prolongation of interbeat interval, whereas baroreflex sensitivity increased from 17.1 to 19.8 ms/mmHg. Baroreflex sensitivity was reduced significantly during mental arithmetic (mean 14.2 ms/mmHg) but not during the cold pressor test (mean 17.4 ms/mmHg). The difference between mental arithmetic and the cold pressor test may be related to the relative intensity of cardiac and vascular responses in the two situations. The implications of these results for the understanding of behavioural influences on haemodynamic function are discussed and the advantages of noninvasive methods are considere

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1989.tb03145.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1989.tb03146.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTAn electrodermal assessment procedure using mild innocuous tones, task‐relevant tones, and loud white noise was administered to a sample of schizophernic patients (n=77). The present study investigated the relationship of schizophrenic symptomatology and anticholinergic level of neuroleptic medication to electrodermal variables. Each patient was evaluated for positive (florid) and negative (defect) symptoms. The neuroleptics that patients received were rated according to their anticholinergic effect.No significant differences in symptomatology were observed between electrodermal responders and nonresponders; however, nonresponders showed a nonsignificant tendency to have more positive and negative symptoms than responders. Both negative symptoms and anticholinergic levels were significant predictors of lower tonic levels of skin conductance. Patients receiving high anticholinergic neuroleptics showed significantly reduced measures of electrodermal responsivity and tonic levels. Thus, both symptomatology and type of neuroleptic are related to electrodermal measures, with the anticholinergic effect of neuroleptic medication being more pronounce

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1989.tb03147.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTThe rise time of an auditory prepulse was varied to determine whether the onset transient of the prepulse is of primary importance in the modification of the acoustic startle reflex. In Experiment 1, 20‐ms long discrete prepulses were presented at a lead time of 150 ms, and prepulse rise time was varied from 0.1 to 20 ms. Although all prepulses resulted in decreased response amplitude (inhibition of startle), varying rise time from 0.1 to 20 ms had no effect on reflex modification. These results suggest that the startle response is not sensitive to prepulse rise time changes in the range used here. In Experiment 2, continuous prepulses (in which lead time equals duration) were presented. Several of these prepulses had a lead time of 150 ms and rise times ranging from 0.1 to 150 ms, whereas others had a rise time of 0.1 ms and lead times of 50 to 150 ms. The results showed that only the fast‐rising, 50‐ms lead time prepulse decreased response amplitude, with the other prepulses having no effect on amplitude, relative to control responding. Rise time changes generally had no effect on responding, but responses were larger at longer lead times than at shorter lead times. Response probability was inhibited by fast‐rising prepulses at lead times of 50 to 130 ms. Together with the results of Experiment 1, these findings suggest that startle reflex inhibition is determined by the onset of a prepulse, and that this inhibition is not sensitive to small changes in prepulse rise time. Also, startle reflex facilitation is determined by the steady‐state portion of the prepulse, and this effect is sensitive to prepulse duration. The inhibitory and facilitatory effects combine to determine the amount and direction of reflex modification, and these effects have different time courses, suggesting different mechanisms. It is suggested that reflex modification is due to the activation of a transient system for startle inhibition and a sustained system for startle fac

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1989.tb03148.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTThe development and independence of short‐term and long‐term habituation (and short‐term sensitization) of the acoustic startle response to repetitive stimuli has been repeatedly demonstrated in the experimental animal. Although short‐term habituation (and sensitization) of acoustic startle has been studied in humans, neither long‐term habituation nor sensitization has been demonstrated. In this study, long‐term habituation (response amplitude decrement) of the blink component of the acoustic startle response occurred in normal men across five consecutive daily sessions of repetitive acoustic stimulation. Long‐term sensitization (onset latency shortening) developed after the third day. Both the long‐term habituation and sensitization were independent of the short‐term habituation, which developed within e

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1989.tb03149.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1989.tb03150.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTThe relationship between blood pressure in the laboratory (both at rest and in response to laboratory tasks) and ambulatory blood pressure at home and at work was evaluated. One hundred nineteen normotensive and unmedicated mild‐moderate hypertensive black and white females and males participated in laboratory blood pressure monitoring at rest and during four challenging tasks (structured interview, video game, bicycle exercise, and cold pressor test) as well as ambulatory blood pressure monitoring while at home and at work. Baseline blood pressure taken while subjects were at rest was the strongest predictor of ambulatory systolic blood pressure (r=.64) and diastolic blood pressure (r=.77) at work. Among reactivity tasks the strongest predictors of ambulatory blood pressure in the total population were the structured interview and the video game (both psychological tasks) followed by the cold pressor test. Racial comparisons, however, determined that the cold pressor test predicted diastolic blood pressure significantly better for blacks (r=.73) than for whites (r=.40), suggesting a possible difference in blood pressure regulatio

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1989.tb03151.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1989.tb03152.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY