Search

It has been clinically observed that psychiatric patients in general (6, 11) and schizophrenic patients in particular (1, 4) show abnormalities of mental speed, being “retarded” or slower than normals on many measures. Confirmatory evidence on this point is to be found but much of the early work on speed of schizophrenic reactivity used measures of speed of motor performance (12, 13) or of reaction time under various conditions (6), ignoring more fundamental slowness of thought processes. The present studies are concentrated on the recent finding that schizophrenics show abnormally slow mental speed measured in a problem-solving situation (4, 18, 19). The aim of the investigation was to discover the exact conditions under which this abnormality appears, and, thence, by manipulating the experimental conditions, to be able to bring speed of mental functioning under experimental control. This paper describes the attempt to bring speed under control by means of drugs. A second paper (2) deals with the effect of practice upon mental speed.

Summary In an attempt to improve the speed of mental functioning of schizophrenics, a group of eight patients was given practice in tests of intellectual speed and level for five consecutive days. Significant improvements attributable to practice were noted, particularly in the speed tests. A similarly marked improvement in mental speed scores was observed in a comparable group of seven normal subjects also tested on five consecutive days. A comparison of the two groups showed that the improvement in mental speed of the schizophrenics was superior to that of the normals, but this was not true in the level test. An experiment on the ldtransfer” of the found improvability of the schizophrenic subjects indicated that the improvement can be generalized, at least to similar tests of mental speed. The results are examined in terms of the concept of reactive inhibition, and the implications of the findings for the treatment of schizophrenics briefly noted.