摘要:

ABSTRACTThis study was designed to assess differences in perception of activity in thezygomaticus major(predominant during smiling) andcorrugator superciliifacial muscles (predominant during frowning). Magnitude production psychophysical methods were used to relate subjective intensity to objective electromyographic activity using a psychophysical power function under four conditions: smiling, frowning, smiling concurrent with maintenance of a frown, and frowning concurrent with maintenance of a smile. High correlation coefficients for each power function for both zygomatic and corrugator activity were obtained. Differences in sensitivity evaluated by comparing the exponent for slope of the power functions showed differences across the muscles and as a function of the conditions. The exponent for frowning was greater than for smiling. Although the exponent for zygomatic activity was similar with and without frowning, significantly greater exponents were shown for corrugator activity when concurrently frowning and smiling than when only frowning. Maximal electromyographic activity was greater in thezygomaticus majormuscle during smiling than in thecorrugator superciliimuscle during frowning. These results provide a methodology for perception of electromyographic activity which could be a useful basis for analysis of the role of perception in regulating affect.

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02181.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02182.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTOur previous event‐related brain potential (ERP) results suggest that during selective listening, relevant stimuli are selected for further processing by comparing each stimulus to an “attentional trace,” a neuronal representation of the physical features of the relevant stimuli that distinguish them from the irrelevant stimuli. This comparison process is reflected by the early component of the processing negativity (PN), which is largest and longest to the relevant stimuli (perfectly matching with the trace). In the present study, the subjects selectively listened to designated tone stimuli which randomly appeared among irrelevant tones of a different pitch. The probability of relevant stimuli in a block was varied. The processing negativity elicited by relevant stimuli was smaller the less frequent they were. The results support the attentional‐trace theory of selective attention, which proposes that, in addition to active maintenance, the trace also depends on the rate of sensory reinforcement provided by the relevant

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02183.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTA simple activity measure based on the EMG recorded from the thigh was developed to monitor the physical activity of ambulatory subjects. The performance of this activity measure was assessed during four major physical activities: running, walking, standing, and sitting. Heart rate was also monitored. The results were analysed within individuals using time series analysis. The heart rate and activity series (of consecutive 30‐s means) required similar models within individuals, and both measures differentiated among running, walking, and non‐movement. The activity measure did not discriminate between postures. This measure covaried closely with heart rate and emerged as a necessary and relatively more significant predictor of heart rate variance than knowledge of the type of physical activity the subjects were undertaking. Posture, however, did add a significant and independent contribution to heart rate variance. This activity measure appears to be a simple, reliable, and valuable method of measurement of physical activity variations in ambulatory subje

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02184.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTLevinson and Edelberg's (1985) recent critique of scoring criteria for electrodermal studies pointed to the need to reduce the latency range used to define the electrodermal response. The present study examined the impact of such a narrowing of the latency window upon habituation and instructional effects in studies of the orienting response to low intensity innocuous stimuli. The first experiment found only a small effect of halving the latency window upon habituation to neutral stimuli, apparent as a strengthening of trends over trials. A second experiment showed somewhat larger effects with significant stimuli, apparent as slightly modified trial and group effects. These data support the view that nothing is to be lost by moving to a narrower latency range to define the electrodermal orienting response to stimulus presentation, and suggest that the advantages of such a change will become increasingly important as nonspecific electrodermal fluctuations increase with increasing electrodermal arousal. An analysis of habituation criteria within this context suggested that the choice of two rather than three no‐response trials to define habituation adds to the benefits obtained by the selection of a narrow latency window to define the respons

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02185.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02186.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTPrincipal components analysis of evoked potentials differing between groups presents an interpretive problem, particularly in psychiatric research. Two sets of principal components and associated factor scores may appear to differ. The issue is to determine the extent to which visually differing principal components and resultant factor scores span the same factor space. Sets of evoked potentials from controls and from schizophrenics were each subjected to principal components analysis, from which factor score coefficients were computed for all subjects. This allowed determination of the extent to which (1) the two sets of basis waves were similar and (2) the factor scores resulting from the set of basis waves derived from principal components analysis of the control subjects’ evoked potential data adequately represented those of the schizophrenics and vice‐versa. Canonical correlation analyses indicated substantial similarities between the principal component structures (sets of basis waves). Multiple correlational analyses confirmed that the basis waves from either group spanned the other group's factor space. Factor scores from either set of basis waves were highly correlated. These results suggest that principal component structures derived from evoked potentials of a control group may be used in computing evoked potential factor scores of psychiatrically diverse populations even though the average evoked potentials of the groups may differ in several w

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02187.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTThe purpose of this paper is to show that the familiar principal component analysis (PCA) of event‐related potentials is identical to an easily formulated least squares method. This correspondence permits interpretation of several criticisms of PCA and clearer presentation of its strengths and shortcomings. Because data analysis based on PCA compares amplitudes of empirically derived components, it is necessary that the shape of the components be similar under the experimental conditions. We present and illustrate a statistical method for comparison of principal components across groups and between conditions within subject

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02188.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Books reviewed in this article:The Polygraph Test: Lies, Truth and Science.Edited by Anthony Gale.Progress in Computer‐Assisted Function Analysis. Edited by J.L. Willems, J.H. van Bemmel,&J. Michel.Psychophysiology: Human Behavior and Physiological Response(2nd.). By John L. Andreas

ISSN:0048-5772    

DOI:10.1111/j.1469-8986.1990.tb02189.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY