Showing papers on "Time perception published in 1977"

Time Perception and Schizophrenia

Abstract: Time perception of 10 schizophrenic patients, 10 nonschizophrenic patients, and 10 normal subjects was compared. The method of estimation was used for four intervals ranging from 5 sec. to 120 sec.; the subject was required to perform a certain task until the experimenter stopped the subject and then to estimate the length of time spent working on the particular task. The results show significant differences between schizophrenics and other subjects in the judgment of 5-sec. intervals. The results partially confirm previous findings and suggest other possible trends not previously reported.

Cerebral asymmetry in time perception

Abstract: Eighteen right-handed male subjects estimated the duration of dot patterns of varying numerosity which were briefly flashed to the left and right visual fields. The mean judged duration of patterns flashed to the left visual field was significantly less than the mean judged duration of patterns flashed to the right visual field. However, the duration of all patterns was underestimated, regardless of visual field. In addition, apparent duration increased linearly when plotted as a function of log duration and increased monotonically when plotted as a function of stimulus numerosity. Overall accuracy was nearly equivalent in both visual fields, but there were interactions between actual durations and visual field and between numerosity and visual field. Thomas and Weaver’s [1975) model for time perception is applied to the data, and it is suggested that the left hemisphere relies on a timer to estimate duration, while the right hemisphere relies on a visual information processor to estimate duration. nt]mis|The author would like to thank A. B. Kristofferson, S. F. Witelson, an anonymous referee, Mary Kay Fortman, and Allen Gouse for their helpful comments. Some of these data were presented at the meeting of the Midwestern Psychological

Reaction time and attention in schizophrenia: a comment on K. H. Nuechterlein's critical evaluation of the data and theories.

Abstract: In his exhaustive review, Nuechterlein (1977) has discussed both the earliest and the most recent contributions to the literature on reaction time (RT) in schizophrenia. Instead of synopsizing this summary or introducing additional research, we have decided to focus on a circumscribed aspect of the literature. In this paper we will be concerned only with the Shakow set paradigm and the Sutton and Zubin cross-modality technique, as well as with their respective theoretical interpretations. Specifically, our objectives are: (1) to compare and contrast both RT techniques in terms of the procedures employed and the variables manipulated; (2) to point out an aspect of the Shakow set paradigm that seems to have been generally overlooked; and (3) to discuss and respond to some comments on the Zubin neuronal trace model. As a necessary preliminary, we will review the two RT procedures in terms of their task requirements and relevant variables. Superficial comparisons of the set and cross-modal RT paradigms often obscure essential differences in method. These discrepancies, in turn, relate to fundamental distinctions between the theoretical constructs and subsystems of attention that are under study in each procedure. In the set procedure, each trial is usually initiated by a warning signal. Thus, in most experiments, the subject has no control over the timing of the onset of a trial. The warning signal initiates a preparatory interval (PI) or waiting period. The subject may have no information about the duration of the PI (uncertain condition), or he may be told whether it will be long or short (certain condition). The duration of the PI may range from a very

Disorders of time perception in endogenous psychoses

Abstract: Already in the normal state of health often there are alterations of subjective time experience both as acceleration and delay of the lapse of time. These impairments of time perception are more important in the psychopathological field. Except during organic brain disease disturbances of time experience are observed especially during endogenous psychoses. Depressed men usually feel an unpleasant extension of subjective time experience. In schizophrenia there is a specific distorsion of time, characterized by troubles of the biographic orientation, by magic connexion-thinking with regard to time, or by a "collapse" of the chronological order. Somatic as well as psychological conditions seem to cause these disturbances.