Size Estimation in Schizophrenics as a Function of Stimulus-Presentation Time.

As expected, good paranoids, normals, and poor nonparanoids tended to low, intermediate, and high estimation levels, respectively, while patient groups differed under the 100-msec.

Abstract

15 good premorbid paranoid acute schizophrenics, IS poor premorbid nonparanoid acute schizophrenics, and IS attendants, all males, estimated stimulus size after receiving (a) 10-sec. and (b) 100-msec. presentations of the standard, also (c) 10-msec. blank flashes instead of the standard. Choices were then made from a group of variable-sized stimuli. As expected, good paranoids, normals, and poor nonparanoids tended to low, intermediate, and high estimation levels, respectively. Contrary to eye-movement interpretation, patient groups differed under the 100-msec. presentation. Lowered estimation level with this presentation suggested stimulus redundancy interpretations. No differences with the blank flash ruled out a simple size-preference response bias. Equal proportions of "hits " among groups indicated that error distributions rather than error frequencies accounted for the results. A recent theoretical formulation of scanning behavior in schizophrenia (Silverman, 1964a) has been developed in part from