Multivariate predictive relationship between kinematic and functional activation patterns in a PET study of visuomotor learning

Imaging studies of visuomotor learning have reported practice-related activ ation in brain regions mediating sensorimotor functions. However, developme nt and testing of functional motor learning models, based on the relationsh ip between imaging and behavioral measures, is complicated by the multidime nsional nature of motoric control. In the present study, multivariate techn iques were used to analyze [O-15]water PET and kinematic correlates of lear ning in a visuomotor tracing task. Fourteen subjects traced a geometric for m over a series of eight tracing trials, preceded and followed by baseline trials in which they passively viewed the geometric form. Simultaneous eval uation of multiple behavioral measures indicated that performance improveme nt was most strongly associated with a global performance measure and least strongly associated with measures of fine motor control. Results of three independent analytic techniques (i.e., intertrial correlation matrices, pow er function modeling, iterative canonical variate analysis) indicated that imaging and behavioral measures were most closely related on early learning trials. Performance improvement was associated with covarying increases in normalized activity among superior parietal, postcentral gyrus, and premot or regions and covarying decreases in normalized activity among cerebellar, inferior parietal, pallidal, and medial occipital regions. These findings suggest that performance improvement may be associated with increased activ ation in neural systems previously implicated in visually guided reaching a nd decreased activation in neural systems previously implicated in attentiv e visuospatial processing, (C) 2000 Academic Press.