The Effect of Informational Feedback on Size Judgements of Schizophrenic Patients

Abstract

This experiment studied visual size judgements of hospitalized schizophrenic patients and normal controls under two conditions of presentation. Sixteen patients and sixteen normal volunteers were required to match for size a graded series of disks at a distance of 14 ft 6 in. with a 4 in. standard at a distance of 5 ft 6 in. Both groups were tested under two conditions: verbal instructions, and verbal instructions with information feedback. The results showed a reduction in error for schizophrenics under the feedback condition. These findings are discussed with reference to the research methodology of procedures which are supposed to provide relative measures of the perceptual capacities of different diagnostic groups.

Schizophrenia and the scanning cognitive control: A reevaluation.

“…It is important to specify conditions under which differences in size judgments or scanning behavior of schizophrenics and normal or psychiatric control 5s are expected to occur and whether these can be eliminated. Stannard, Singer, and Over (1966) reported that differences between the performance of schizophrenic and normal Ss on a size-constancy task under normal motivation conditions were eliminated when behavior was manipulated using impersonal reinforcement in an operant procedure.…”