Neural correlates of a decision in the dorsolateral prefrontal cortex of the macaque

To make a visual discrimination, the brain must extract relevant information from the retina, represent appropriate variables in the visual cortex and read out this representation to decide which of two or more alternatives is more likely. We recorded from neurons in the dorsolateral prefrontal cortex (areas 8 and 46) of the rhesus monkey while it performed a motion discrimination task. The monkey indicated its judgment of direction by making appropriate eye movements. As the monkey viewed the motion stimulus, the neural response predicted the monkey's subsequent gaze shift, hence its judgment of direction. The response comprised a mixture of high-level oculomotor signals and weaker visual sensory signals that reflected the strength and direction of motion. This combination of sensory integration and motor planning could reflect the conversion of visual motion information into a categorical decision about direction and thus give insight into the neural computations behind a simple cognitive act.