This proposal examines the neural control representation of reach-to-grasp in non-human primates. The neuronal coding of reach-to-grasp in the primary motor cortex, M1, and the ventral premotor cortex, PMv, will be examined within the context of a widely accepted categorical scheme for prehensile movements; power versus precision grasp. Although deeply embedded in the literature and researchers' theoretical framework, there is limited support for a central representation of a precision versus power categorical scheme. The objective of this grant proposal is to provide evidence that power and precision grasps lie on a continuum of hand shaping control strategies rather than as two distinct control strategies. The general hypothesis of a prehensile continuum will be tested via four specific aims: i) investigate the effects of object constraint on grasp type, ii) demonstrate that power and precision grasps will vary systematically along a 2-dimensional continuum of hand shape and grasp force, iii) fully explore the relationship between force production and hand shaping, and iv) demonstrate that representations of a prehensile continuum are found in both PMv and M1. Cell modulations, kinematic and kinetic variables, and EMG muscle activity will be recorded and analyzed. This research will provide insight into the control mechanisms involved in highly complex prehensile movements. These findings can be translated into clinically relevant terms for the habilitation/rehabilitation of neurological patients with motor control impairments.
| Hendrix, Claudia M; Mason, Carolyn R; Ebner, Timothy J (2009) Signaling of grasp dimension and grasp force in dorsal premotor cortex and primary motor cortex neurons during reach to grasp in the monkey. J Neurophysiol 102:132-45 |
| Theverapperuma, Lalin S; Hendrix, Claudia M; Mason, Carolyn R et al. (2006) Finger movements during reach-to-grasp in the monkey: amplitude scaling of a temporal synergy. Exp Brain Res 169:433-48 |
| Mason, Carolyn R; Hendrix, Claudia M; Ebner, Timothy J (2006) Purkinje cells signal hand shape and grasp force during reach-to-grasp in the monkey. J Neurophysiol 95:144-58 |
| Mason, Carolyn R; Theverapperuma, Lalin S; Hendrix, Claudia M et al. (2004) Monkey hand postural synergies during reach-to-grasp in the absence of vision of the hand and object. J Neurophysiol 91:2826-37 |
