The modification of schizophrenic performance by drugs and by positive reinforcement

Abstract

The purpose of the present study was to determine whether positive reinforcement, chlorpromazine and secobarbital alter the ability of chronic schizophrenics to maintain sustained attention and whether these affect their psychomotor functioning. Eight male, chronic schizophrenic patients, with an age range of 25-50 and in good physical health, served as the subjects. All subjects had been hospitalized continuously for at least three years. Medication was discontinued for all subjects two months before the study started. In the course of the study, each subject was tested twice under all of the following conditions: no-drug, placebo, chlorpromazine 100 mg, chlorpromazine 200 mg, secobarbital 100 mg, secobarbital 200 mg. The drugs were given once weekly in single doses. A testing day consisted of four sessions: 1/2, 1 1/2, 2 1/2, and 3 1/2 hours post-medication. The different drug conditions were administered according to a modified Latin Square design with each active drug following each other active drug an equal number of times. Half of the trials in each session were reinforced by candy and cigarettes and the other half were not. Two tests were employed: The Continuous Performance Test (CPT), and the Subject Paced Test (SPT). On the CPT, a test of sustained attention, a subject is required to respond, by pulling a lever, to one of twelve letters which are randomly exposed at the rate of 1.10 sec. for a period of .10 second.[TRUNCATED]