LATERALIZED INCREASES IN CEREBRAL BLOOD-FLOW DURING PERFORMANCE OF VERBAL AND SPATIAL TASKS - RELATIONSHIP WITH PERFORMANCE-LEVEL

Physiologic neuroimaging studies have shown lateralized regional incre ase in brain activity during cognitive tasks, but the hypothesis that such changes are correlated with task performance has not been tested directly. We examined cerebral blood flow (CBF) changes induced by cog nitive tasks in relation to performance. CBF was measured with the (13 3)Xenon clearance method in 34 normal right-handed young (age < 30) vo lunteers during resting baseline and during the performance of a verba l analogies and a spatial line orientation test. Performance measures included ''speed'' and ''power'' estimates of both activation tasks. R esting CBF was moderately correlated with performance. The correlation s were slightly higher with activated CBF for verbal but not spatial p erformance. The degree of increase (task-baseline) did not correlate w ith performance for either task. The highest and topographically speci fic correlations were obtained between laterality of CBF and verbal pe rformance. Higher left hemispheric activation was correlated with verb al performance, and this correlation was significantly higher in the a ngular gyrus region. For the spatial task the correlations were with r elatively higher right hemispheric activation but without regional spe cificity. The results underscore the importance of integrating behavio ral performance data with physiologic measures in neuroimaging activat ion studies. (C) 1994 Academic Press, Inc.