Halstead's Category Test and lateralized brain damage.

Summary.-Left-hemisphere-damaged (with Verbal IQ deficits) and right- hemisphere-damaged (with Performance IQ deficits) male, adult patients were compared on Halstead Category Test Performance. Deficits of approximately the same magnitude were found. These results and other evidence question the importance of language mediation on nonverbal, visual-spatial abstracting tests. The differential psychological effects of lateralized brain damage have been well documented (e.g., Parsons, 1970). One question of importance is whether abstracting behavior on non-verbal tasks is differentially affected by lateralicy of lesion. If, for example, left-hemisphere-damaged patients perform more poorly on a nonverbal test than right-hemisphere-damaged patients, importance of im- plicit language in abstracting behavior would be emphasized. Results with the Halstead Category Tesc, a nonverbal, visual-spatial abstracting test sensitive to brain damage, offers the opportunity to investigate the question. Shure and Halstead (1968) found that patients with left damage performed more poorly than those with right damage. Chapman and Wolff (1959) found a trend for the opposite relationships while Doehring and Reitan (1962) found no differ- ences in their lateralized lesion groups. Reitan (1960) also compared Ss with and without definite organic language deficits and found no inter-group differ- ences. In the course of a larger study of brain-behavior relationships (Parsons, Vega, & Burn, 1969) it was possible to re-examine this problem with several methodological improvements over previous studies. Thus, groups of brain- damaged Ss were studied who were equated for their general level of psychologi- cal impairment and in whom the left-hemisphere-damaged persons manifested significant deficit on the WAIS Verbal Scale than the Performance Scale and the opposite relationship was present for the right-hemisphere-damaged Ss. Ss have been previously described in detail (Parsons, Vega, & Burn, 1969). Clearly diagnosed male, middle-aged Ss were placed into four groups: primarily left-hemisphere damage (N = 21), primarily right-hemisphere damage (N = 19), bilateral or diffuse damage (N = 36), and non-brain-damaged Ss (N = SO). Ss were given Halstead's Category Test as part of the complete Halstead battery, and the WAIS. A detailed description of Halstead's Category Tesc is provided by Simmel and Counts (1957). Of the seven subrests, 1 and 2 are introductory and 7 is a review; therefore, data for subtests 3, 4, 5 and G were analyzed.