Prefrontal cortex is involved in internal decision of forthcoming saccades

Deciding where to look is mandatory to explore the visual world. To study the neural correlates subserving the cognitive phase of self-initiated eye movements in humans, we tested 12 healthy participants, using event-related functional MRI. Changes in the frontal-cortical activity preceding voluntary saccades were studied when the participants freely decided the direction of a forthcoming saccade, compared with a condition in which they had only to prepare an externally cued saccade. Self-initiation of saccades, before their execution, was specifically associated with frontal-lobe activation in the dorsolateral prefrontal cortex, and in the right presupplementary eye field and frontal eye fields, suggesting the roles of these areas in the decision process of where to look when facing two possible visual targets.