Patterns of performance by neuropsychiatric patients on the halstead category test: evidence for conceptual learning in schizophrenic patients.

We attempted to determine whether schizophrenic patients can improve their performance on an abstract reasoning task through experience, and to ascertain how the degree of learning compares with brain-damaged patients and patient controls. Two hundred and two schizophrenic patients, 179 brain-damaged patients and 229 patient controls were compared with regard to their improvement on Subtest 6 relative to Subtest 5 of the Halstead Category Test. Since Subtests 5 and 6 are based on the same concept, experience with Subtest 5 should reduce errors on Subtest 6. Subjects were also compared on Subtest 7, which evaluates learning and retention of the concepts associated with subtests 1 to 6. the schizophrenic subjects showed improvement on subtests 6 relative to 5 that was equal to the controls, with both groups showing significantly greater improvement than the brain-damaged subjects. The schizophrenic subjects also obtained a better mean score on Subtest 7 than did the brain-damaged subjects, but made significantly more errors than controls. We conclude that schizophrenic patients are capable of conceptual learning, and may not have fixed, irreversible impairment of abstraction ability.