Article

Converging evidence from neurological patients and functional brain imaging
studies strongly supports the notion that the posterior parietal cortex (PPC),
especially in the left hemisphere, plays a critical role in both the programming
(i.e., setting the initial movement parameters of the reach) and the online
control of goal-directed reaching movements. Importantly, however, there is no
clear consensus on how different subregions within the PPC contribute to the
programming and online control of reaching. In the current study, we investigated
the role of the inferior (IPL) and superior (SPL) parietal lobules in reach
programming using MRI-guided event-related transcranial magnetic stimulation
(TMS). Specifically, we applied triple-pulse (tp) TMS to either the left IPL or
the left SPL at different time points during reaching movements either at target
onset (programming) or at movement onset (online control) while participants
(n=16) made pointing movements to targets in the periphery without visual
feedback of the moving hand. Stimulating the SPL but not the IPL resulted in a
significant increase in endpoint errors when tp-TMS was applied during the
programming phase compared to the online control phase. In short, these data
demonstrate that the SPL plays a critical role in real-time movement programming.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS