Suppression of visual responses of neurons in inferior temporal cortex of the awake macaque by addition of a second stimulus.

The responses of neurons, in inferior temporal cortex of the awake macaque, to single stimuli and pairs of stimuli were examined. The responses of most neurons were weaker to pairs of stimuli than to the best single stimulus of that pair presented alone. This 'suppression by a second stimulus' did not appear to be stimulus-selective and the suppression was greater when the second stimulus appeared in receptive field locations that exhibited weaker responses. This phenomenon suggests competitive interactions between IT neurons that may be involved in visual attention or learning or both.