Frontal Mechanisms of Visuomotor Control



 DESCRIPTION (provided by applicant): In daily life, one uses sensory information and attention to select appropriate actions. Very often, we think of sensory information as "guiding" our choices, leading to the intuition that perception and action operate serially. Understanding the cortical mechanisms by which the brain links these processes, and to what extent spatial attention affects the handoff from sensory to motor activity, is crucial to understanding frontal control of perceptual decision making. Previous studies have found that in simple detection tasks, visual neurons in the primate frontal eye fields select targets before motor action. The lab of Stanford and Salinas, however, has demonstrated that when perceptual discrimination is couched in the context of an urgent-decision task, motor activity evolves simultaneously with perception. The proposed research is designed to use an urgent-decision paradigm combined with an attentional probe, applied across tasks of differing attentional demands, to investigate the temporal correlates of visual and motor activity, as well as the effect of attentional bias. Ths work uses single-unit electrophysiological recordings from awake-behaving rhesus monkeys performing a series of saccadic eye-movement tasks. These recordings are used to compare activity between easy and urgent versions of tasks requiring endogenous and exogenous attentional allocation. With this data, the evolution of the perceptual information into motor response, and whatever modulatory effect attention has, can be explored for a variety circumstances. The proposed study will have valuable implications for the understanding of the neural basis of perceptual decision, response selection, and attentional modulation of perceptual processing. Elucidating the neural mechanisms responsible for linking attention, perception, and action is fundamental to a thorough understanding of many pathological conditions associated with disruptions in the ability to produce goal-driven behaviors, including Parkinson's disease, schizophrenia, neglect, stroke, and various other cognitive disorders.