A neural model of hand grip formation during reach to grasp

We investigate the spatio temporal dynamics of hand pre-shaping during prehension through a biologically plausible neural network model. It is proposed that the hand grip formation in prehension can be understood in terms of basic motor programs that can be rescaled both spatially and temporally to accommodate different task demands. The model assumes a timing coordinative role to propioceptive reafferent information generated by the reaching component of the movement, avoiding the need of a pre-organized functional temporal structure for the timing of prehension as some previous models have proposed. Predictions of the model in both normal and altered initial hand aperture conditions match key kinematic features present in human data. The differences between the proposed model and previous models predictions are used to try to identify the major principles underlying prehensile behavior.