TY - JOUR T1 - Reaching Activity in the Medial Posterior Parietal Cortex of Monkeys Is Modulated by Visual Feedback JF - The Journal of Neuroscience JO - J. Neurosci. SP - 14773 LP - 14785 DO - 10.1523/JNEUROSCI.2313-10.2010 VL - 30 IS - 44 AU - Annalisa Bosco AU - Rossella Breveglieri AU - Eris Chinellato AU - Claudio Galletti AU - Patrizia Fattori Y1 - 2010/11/03 UR - http://www.jneurosci.org/content/30/44/14773.abstract N2 - Reaching and grasping an object is an action that can be performed in light, as well as in darkness. Area V6A is a visuomotor area of the medial posterior parietal cortex involved in the control of reaching movements. It contains reaching neurons as well as neurons modulated by passive somatosensory and visual stimulations. In the present work we analyze the effect of visual feedback on reaching activity of V6A neurons. Three macaques were trained to execute reaching movements in two conditions: in darkness, where only the reaching target was visible, and in full light, where the monkey also saw its own moving arm and the environment. Approximately 85% of V6A neurons (127/149) were significantly related to the task in at least one of the two conditions. The majority of task-related cells (69%) showed reach-related activity in both visual conditions, some were modulated only in light (15%), while others only in dark (16%). The sight of the moving arm often changed dramatically the cell's response to arm movements. In some cases the reaching activity was enhanced and in others it was reduced or disappeared altogether. These neuronal properties may represent differences in the degree to which cells are influenced by feedback control versus feedforward movement planning. On average, reach-related modulations were stronger in light than in dark, a phenomenon similar to that observed in brain imaging experiments in the human medial posterior parietal cortex, a region likely homologous to macaque area V6A. ER -