Neural correlates of visual and motor decision processes

Recent research has clarified and revealed characteristics of perceptual and motor decision processes in the brain. A democracy of sensory neurons discriminate the properties of a stimulus, while competition contrasts the attributes of stimuli across the visual field to locate conspicuous stimuli. Salience and significance are weighed to select an object on which to focus attention and action. Experimentally combining neural and mental chronometry has determined the contribution of perceptual and motor processes to the duration and variability of behavioral reaction time. Whereas perceptual processing occupies a relatively constant amount of time for a given stimulus condition, the processes of mapping particular stimuli onto the appropriate behavior and preparing the motor response provide flexibility but introduce delay and variability in reaction time.