Strategy-dependent encoding of planned arm movements in the dorsal premotor cortex.

The kinematic strategy encoded in motor cortical areas for classic straight-line reaching is remarkably simple and consistent across subjects, despite the complicated musculoskeletal dynamics that are involved. As tasks become more challenging, however, different conscious strategies may be used to improve perceived behavioral performance. We identified additional spatial information that appeared both in single neurons and in the population code of monkey dorsal premotor cortex when obstacles impeded direct reach paths. The neural correlate of movement planning varied between subjects in a manner consistent with the use of different strategies to optimize task completion. These distinct planning strategies were manifested in the timing and strength of the information contained in the neural population code.