Hemisphere asymmetry for imitation of hand and finger movements, Goldenberg's hypothesis reworked.

Goldenberg and co-workers put forward the hypothesis that coding of hand gestures with respect to body parts depends upon the functioning of the left hemisphere while the right hemisphere would be involved in imitation of finger postures. They supported this claim with experimental evidence from lesion studies, however, they failed to back it up with functional neuroimaging data. To verify Goldenberg's hypothesis on hemisphere asymmetries for hand/finger postures imitation, the performance of 35 patients with left hemisphere lesion (L/pts), of 24 patients with right hemisphere lesion (R/pts) and that of 41 matched controls was assessed in two imitation tasks, respectively, taxing hand or finger postures. The data, adjusted for the performance of the controls and for the effect of age were analysed using a multivariate, nonparametric approach. The outcome partly supports Goldenberg and colleagues' hypothesis: hand minus finger performance did differs between the R/pts and L/pts patients, even considering the pertinent hand-finger performances by control participants, however, in line with neuroimaging evidence, the left hemisphere's contribution is greater than that of the right for both finger and hand posture imitation.