FURTHER STUDIES ON THE SPEECH PATTERNS OF SCHIZOPHRENIC PATIENTS1

Abstract

A pilot study was first done on 14 schizophrenic patients to test the capacity of a verbal behavior analysis procedure to discriminate accurately among individuals as to the severity of the schizophrenic syndrome[long dash]specifically the degree of social alienation and personal disorganization[long dash]as compared to a clinical criterion measure. The rank-order correlation of the verbal behavior measure and the criterion measure was 0.55, significant at the .05 level (one-tail test). Thereupon, verbal samples were obtained from and scored on 152 chronic schizophrenic patients. This group was randomly split into 2 groups of equal size for purposes of cross validation. The total verbal behavior indices calculated from those verbal samples, containing 45 words or more, predicted each of 3 criterion rating scales and the combined criterion measure at or beyond the 0.001 level of significance. The correlation with the total criterion rating was 0.53 in Subgroup I and 0.60 in Subgroup n. Of the 152 schizophrenic patients 39 spoke less than 45 words in response to the verbal test instructions, and these verbal samples were not included in the above correlation, for they were assumed to be minimally representative of the individuals in terms of content. However, such reticent patients were rated on the clinical criterion measure and as a group were much sicker than the non-reticent group. They had an average rating of 21.5 as compared to 13.2 for the non-reticent group, a difference which is significant at the .001 level. Paucity or lack of speech under our test conditions, then, also provides a validated measure of severity of illness. The weighting of categories in our verbal scale was refined by making the weights more nearly proportional to the independent contribution of each category to the prediction of severity of schizophrenic syndrome. The possible application to psychiatric re-search of this verbal behavior measure of severity of schizophrenic syndrome is suggested.