In daily life, successful actions must be informed by veridical sensory information. Thus, sensory driven behavior is typically thought of as a serial process consisting of a perceptual discrimination followed by selection of the appropriate motor response. Understanding how the brain links these processes is fundamental to our understanding of sensorimotor decision-making and has been the focus of many recent studies. In the case of saccadic eye movements to visual goals, previous studies have demonstrated a neural correlate of """"""""choosing"""""""" a target from among competing alternatives in the macaque frontal cortex. In tasks requiring a simple perceptual discrimination, the activity of neurons in the frontal eye fields (FEF) evolves over time to discriminate between a target and distracter and is presumed to part of the neural substrate for target selection. However, because the transition from perceptual discrimination to response selection has no overt behavioral manifestation, it has been difficult, if not impossible, to determine if neurons with target/distracter discrimination represent the perceptual discrimination, motor response selection, or both. In addition, while most """"""""target selection"""""""" studies have focused on cortex (e.g. FEF);there is evidence to suggest that subcortical regions such as the thalamus, superior colliculus, basal ganglia, and cerebellum contribute to shaping cortical activity. Whether subcortical-cortical interactions constitute a functional hierarchy for decision-making is currently unknown. Here I to address these questions by recording from neurons in the FEF and oculomotor thalamus during performance of a novel compelled-saccade task. By providing independent experimental control over the times of perceptual processing and response selection, the compelled-saccade task will permit unambiguous differentiation of activity related to these two phases in the production goal-directed behavior. The results of these studies will have critical implications for our understanding of the neural basis of perceptual decision and response selection and the way in which these two functions are coordinated within a functional hierarchy of cortical and subcortical structures. Elucidating the neural mechanisms responsible for allowing a flexible linkage between sensation and action will be fundamental to a thorough understanding of many pathological conditions associated with disruptions in the ability to produce goal-driven behaviors including, Parkinson's disease, stroke, neglect, schizophrenia, and numerous other cognitive disorders.
Elucidating the neural mechanisms and anatomical substrates responsible for allowing a flexible linkage between sensation and action will be fundamental to a thorough understanding of many pathological conditions associated with disruptions in the ability to produce goal-driven behaviors including, Parkinson's disease, stroke, neglect, schizophrenia, and numerous other cognitive disorders.
| Costello, M Gabriela; Zhu, Dantong; May, Paul J et al. (2016) Task dependence of decision- and choice-related activity in monkey oculomotor thalamus. J Neurophysiol 115:581-601 |
| Costello, M Gabriela; Zhu, Dantong; Salinas, Emilio et al. (2013) Perceptual modulation of motor--but not visual--responses in the frontal eye field during an urgent-decision task. J Neurosci 33:16394-408 |
| Shankar, Swetha; Massoglia, Dino P; Zhu, Dantong et al. (2011) Tracking the temporal evolution of a perceptual judgment using a compelled-response task. J Neurosci 31:8406-21 |
