Gestalt Perception in schizophrenia

196

GESTALT

PERCEPTION

IN SCHIZOPHRENIA

W. Rief* and R. Cohen** *Klinik Roseneck, Am Roseneck 6, 8210 Prien am Chiemsee; sitit Konstanz, P.O. Box 5560, D-7750 Konstanz, FRG

**Univer-

Place and Gilmore (1) proposed that schizophrenics have deficits in the perceptual organization of visual stimuli. In their study, largely replicated by Wells and Leventhal (2), they interpreted their findings as showing that schizophrenics do not organize visual information according to the Gestalt principles of similarity and proximity. According to the experimental approach of Place and Gilmore (l), 24 schizophrenics, 12 alcoholics, and 24 healthy controls had to report the number of lines presented for 23 msec on a video screen. Stimuli displays in one of the experimental conditions were identical to Place and Gilmore: up to six lines were presented at the corners of an imaginary hexagon. In another block of trials, the lines appeared at 10 different positions in the same field. There were two types of stimuli arrangements: (1) homogeneous - all lines show the same orientation and were either horizontal or vertical; (2) heterogeneous - adjacent lines had different orientations. If the basic configuration was a hexagon, the performance of the schizophrenics was again found to be less influenced by different orientations of the lines. But in contrast to the results of Place and Gilmore (1) and in partial agreement with the results of Wells and Leventhal (21, schizophrenics in our study excelled in recognizing six lines when line orientation was homogeneous and when the configuration was hexagonic, i.e., when the global Gestalt was prominent. Thus, schizophrenics may behave differently in using some Gestalt principles. On the other side, they can take into account the properties of the global Gestalt of the standard display. 1.

organization in E.J.S., Gilmore, G.C. Perceptual Place, schizophrenia. Journal Abnormal Psvcholoav 89:409-418, 1980

2.

Wells, D-S., Leventhal, D.B. Perceptual grouping in schizophrenia: a replication of Place & Gilmore. Journal Abnormal Psychology 93:231-234, 1984

PROLONGED PHRENICS:

REACTION TIMES (RT) AFTER FURTHER EXPLORATIONS

STIMULUS

ALTERNATION

IN SCHIZO-

Fred Rief and Rudolf Cohen University

of Konstanz,

Postfach

5560, D-7750 Konstanz

1, FRG

studies are presented to further elucidate the Data from several Modality Shift Effect (MSE), first described by Sutton et al (1963). In the standard condition tone and light stimuli follow each other in