Modest Gaze-Related Discharge Modulation in Monkey Dorsal Premotor Cortex During a Reaching Task Performed With Free Fixation
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Open Access
- 1 August 2002
- journal article
- Published by American Physiological Society in Journal of Neurophysiology
- Vol. 88 (2) , 1064-1072
Abstract
Recent studies have shown that gaze angle modulates reach-related neural activity in many cortical areas, including the dorsal premotor cortex (PMd), when gaze direction is experimentally controlled by lengthy periods of imposed fixation. We looked for gaze-related modulation in PMd during the brief fixations that occur when a monkey is allowed to look around freely without experimentally imposed gaze control while performing a center-out delayed arm-reaching task. During the course of the instructed-delay period, we found significant effects of gaze angle in 27–51% of PMd cells. However, for 90–95% of cells, these effects accounted for <20% of the observed discharge variance. The effect of gaze was significantly weaker than the effect of reach-related variables. In particular, cell activity during the delay period was more strongly related to the intended movement expressed in arm-related coordinates than in gaze-related coordinates. Under the same experimental conditions, many cells in medial parietal cortex exhibited much stronger gaze-related modulation and expressed intended movement in gaze-related coordinates. In summary, gaze direction-related modulation of cell activity is indeed expressed in PMd during the brief fixations that occur in natural oculomotor behavior, but its overall effect on cell activity is modest.Keywords
This publication has 28 references indexed in Scilit:
- Reach Plans in Eye-Centered CoordinatesScience, 1999
- Differential relation of discharge in primary motor cortex and premotor cortex to movements versus actively maintained postures during a reaching taskExperimental Brain Research, 1996
- Deciding Not to GO: Neuronal Correlates of Response Selection in a GO/NOGO Task in Primate Premotor and Parietal CortexCerebral Cortex, 1995
- Theoretical Considerations for the Analysis of Population Coding in Motor CortexNeural Computation, 1994
- Neuronal specification of direction and distance during reaching movements in the superior precentral premotor area and primary motor cortex of monkeysJournal of Neurophysiology, 1993
- Effects of gaze on apparent visual responses of frontal cortex neuronsExperimental Brain Research, 1993
- Premotor cortex of monkeys: set- and movement-related activity reflecting amplitude and direction of wrist movementsJournal of Neurophysiology, 1993
- Movement-related neuronal activity selectively coding either direction or muscle pattern in three motor areas of the monkeyJournal of Neurophysiology, 1990
- Preparation for movement: neural representations of intended direction in three motor areas of the monkeyJournal of Neurophysiology, 1990
- Monkey primary motor and premotor cortex: single-cell activity related to prior information about direction and extent of an intended movementJournal of Neurophysiology, 1989