Role of the Dorsolateral Prefrontal Cortex in Organizing Visually Guided Behavior

Abstract

Unit activity was recorded in the prefrontal cortex of rhesus monkeys during performance of a delayed task with two motor responses, a saccade and an arm movement, to a complex pattern of auditory and visual stimuli. The peculiarity of the paradigm was that onset of the different sensory stimuli, orienting saccade and arm movement, were dissociated in time and occurred at prefixed time intervals. Two hundred and sixteen task-related units were recorded. The data show that the dorsolateral part of the prefrontal cortex plays a crucial role in temporal organization of visually guided behaviour. This cortical area contains the neural substrate of an encoding strategy for remembered or current events and objects in the behavioural surround that are not, as yet, foveated. This encoding mechanism subserves a particular cognitive process. Whether events or objects are, or are not, encoded depends on their significance for future behaviour. While foveation deletes their neural trace, it activates a class of cells that appear involved in the preparation of arm movements towards the foveated region. The destruction of these two complementary mechanisms would disrupt the organism''s capacity to integrate temporally and spatially discontinuous information for performance of goal-directed acts.