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Changes in Body Perception During Repeated Trials USPHS

Baker, A. Harvey; Schlater, Jerry A.; Wapner, Seymour
Publication Year:
Report Number:
ETS Research Memorandum
Document Type:
Page Count:
Subject/Key Words:
National Institute of Mental Health, United States Public Health Service (USPHS), Body Image, Kinesthetic Perception, Perception Tests, Responses


From previous experiments it was found that when the hand was in active contact with an object, perceived length of outstretched arm was greater than when the hand was in passive contact with the same object, and it was inferred that the repetitive stimulation provided by repeated trials induced a "body-directedness" from the "object-directedness" present before the trials. It was then hypothesized that perceived length of outstretched arm would decrease from the beginning to the end of a series of repeated trials. This hypothesis was investigated using pretest and posttest data culled from a larger study on the effects of body- and object-directed conditions on perceived arm length. Possible alternative explanations of the findings as due to 1) fatigue, 2) adaptation level effects of the intervening conditions or 3) temporal change in the effect of the psychophysical procedures were considered and found unsatisfactory in explaining the results. Argument is made that shift in perceived arm length observed in this study is due to a shift in attitude from active, object-directed to passive, body-directed over repeated trials.

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