Background Activity in Single Cells of Monkey Visual Cortex During Visual Tracking

Abstract

For 39 neurons in the visual cortex of 3 monkeys, background firing rate was compared in visual tracking and rest conditions. The cells fell into 2 qualitatively different classes: 34 showed small changes with visual tracking, while 5 showed dramatic and long-lasting suppressions. In the first group, activity during the tracking condition was lower than that during rest (t-test sig. at. 02 level), though some cells increased their firing rates and the change is better seen as a repatterning. The second group showed a strong tracking-induced suppression which eliminated all background activity and required up to one minute of rest for recovery. The length of this period suggests that a tonic influence from another brain area rather than a simple inhibition underlies the phenomenon, which probably relates to visual attention.