The question of how the transport and grasp components in prehension are spatio-temporally coordinated is addressed in this paper. Based upon previous works by Castiello [1] we hypothesize that this coordination is carried out by neural networks in basal ganglia that exert a sophisticated gating / modulatory function over the two visuomotor channels that according to Jeannerod [2] and Arbib [3] are involved in prehension movement. Spatial dimension and temporal phasing of the movement are understood in terms of basic motor programs that are re-scaled both temporally and spatially by neural activity in basal ganglia thalamocortical loops. A computational model has been developed to accommodate all these assumptions. The model proposes an interaction between the two channels, that allows a distribution of cortical information related with arm transport channel, to the grasp channel. Computer simulations of the model reproduce basic kinematic features of prehension movement.