Perceptual organization in persons vulnerable to schizophrenia

In 1980 Place and Gilmore (J. of Abnormal Psychol., 89(3), 409-418) concluded that a perceptual deficit in schizophrenia may be expressed as a failure to organize information at an early stage of processing. Yet, Place & Gilmore's findings may be questioned on two points. First, in light of the symptomotology involved in schizophrenia, Place and Gilmore's (1980) findings raise the question of whether the deficit was the result of schizophrenic symptomotology (i.e. clinical state) or a result of an underlying vulnerability to schizophrenia (i.e. trait). The second point of question involves the procedure utilized by Place & Gilmore (1980) and later replicated by Wells & Leventhal (1984). The utilization of a 500 ms blank exposure following the tachistoscopic target presentation raises the possibility of a masking by light effect on performance, a possibility that was not taken into account by either Place & Gilmore (1980) or Wells & Leventhal (1984). In an attempt to eliminate these confounding variables, the present proposed study will compare the performance of persons who have averted the clinical syndrome but are hypothetically vulnerable to schizophrenia (schizotypics), as determined by the 2-7-8 MMPI profile, to the performance of individuals with normal MMPI profiles on a modified version of the Place & Gilmore (1980) task. The modified version of the task involves the added condition of "without the 500 ms blank exposure". In addition to the 2-7-8 and "inflation-free" groups, a 4-9 "psychiatric control" group and an additional schizotypic 8-9 MMPI, group will be utilized. All subjects will receive both conditions (with versus without the blank light exposure). Differences in mean group line counting performance will be analyzed in a four-way ANOVA with two repeated measures. It is hypothesized that the schizotypics will more accurately perform the line-counting task than both the "inflation free" and 4-9 groups in the condition that replicates Place & Gilmore (1980). However, a masking effect is expected to be manifested by more accurate line counting overall in the "no light" condition. Results will be analyzed in reference to the perceptual grouping literature (Treisman, 1982) the masking by light literature (Breitmeyer, 1984) and the literature on vulnerability to schizophrenia (Zubin & Spring, 1977).Thesis (M.A.