Modifications of presaccadic activation on neurons in the extrastriate cortex during prolonged training of rhesus monkeys in a visuo-oculomotor task.

As a monkey learns to make a saccadic eye movement to a constantly illuminated peripheral stimulus the majority of cells in visual association cortex at the prelunate gyrus are activated before the eye movement (presaccadic activation, PSA). We recorded eye movements and this PSA extracellularly from single cells of behaving monkeys by microelectrode penetrations made during consecutive days of training. The PSA gradually disappears as training continues for some weeks. At the same time the animal's performance improves and saccadic reaction times decrease. The visuo-oculomotor task seems to be automated and its execution no longer needs a strong activation of the visual association cortex.