Preparatory activity links the frontal eye field response with small amplitude motor unit recruitment of neck muscles during gaze planning

Rungta, S and Basu, D and Sendhilnathan, N and Murthy, A (2021) Preparatory activity links the frontal eye field response with small amplitude motor unit recruitment of neck muscles during gaze planning. In: Journal of Neurophysiology, 20 (7). pp. 451-463.

PDF jou_neu_20-07_451-463_2021.pdf - Published Version Restricted to Registered users only Download (5MB) | Request a copy

Abstract

A hallmark of intelligent behavior is that we can separate intention from action. To understand the mechanism that gates the flow of information between motor planning and execution, we compared the activity of frontal eye field neurons with motor unit activity from neck muscles in the presence of an intervening delay period in which spatial information regarding the target was available to plan a response. Although spatially specific delay period activity was present in the activity of frontal eye field neurons, it was absent in motor unit activity. Nonetheless, motor unit activity was correlated with the time it took to initiate saccades. Interestingly, we observed a heterogeneity of responses among motor units, such that only units with smaller amplitudes showed a clear modulation during the delay period. These small amplitude motor units also had higher spontaneous activity compared with the units which showed modulation only during the movement epoch. Taken together, our results suggest the activity of smaller motor units convey temporal information and explains how the delay period primes muscle activity leading to faster reaction times. NEW & NOTEWORTHY This study shows that the temporal aspects of a motor plan in the oculomotor circuitry can be accessed by peripheral neck muscles hundreds of milliseconds before the instruction to initiate a saccadic eye movement. The coupling between central and peripheral processes during the delay time is mediated by the recruitment pattern of motor units with smaller amplitude. These findings suggest that information processed in cortical areas could be read from periphery before execution. © 2021 the American Physiological Society.

Item Type:	Journal Article
Publication:	Journal of Neurophysiology
Publisher:	American Physiological Society
Additional Information:	The copyright for this article belongs to American Physiological Society
Keywords:	article; brain cortex; controlled study; frontal eye field; gaze; human; human experiment; muscle function; nape; neck muscle; neurophysiological recruitment; reaction time; saccadic eye movement; nerve cell
Department/Centre:	Division of Biological Sciences > Centre for Neuroscience Division of Physical & Mathematical Sciences > Mathematics
Date Deposited:	20 Nov 2021 11:30
Last Modified:	20 Nov 2021 11:30
URI:	http://eprints.iisc.ac.in/id/eprint/69847

Actions (login required)

View Item