One of the most important questions in neuroscience today concerns the mechanisms by which sensory neurons give rise to perceptual experience. There are many ways to address this question, which have long populated the field of visual neuroscience. Prominent among them is the study of visual selectivity. Observers are highly sensitive to some visual stimuli and less sensitive to others. Visual neurons are also highly selective: Each responds to a limited range of stimuli along several stimulus dimensions. The proposed research aims to understand how the selective pattern of neuronal responses accounts for the observer?s selective perceptual experience and discriminative capacity. This understanding will be achieved through experiments that first evaluate patterns of neuronal selectivity for visual stimuli that vary in their spatial and temporal properties. Second, these data, in combination with manipulations of stimulus context, will be used to develop a novel mechanistic account of neuronal selectivity based on activity within cortical visual circuits stabilized by inhibition. Finally, to understand how neuronal selectivity underlies perceptual experience, direct comparisons will be made between physiological measures of neuronal selectivity and behavioral measures of perceptual selectivity, assessed concurrently under identical conditions. The proposed research constitutes a richly interwoven collection of psychophysical, neurophysiological and theoretical approaches to understanding of spatial and temporal vision. The experiments will yield an unprecedented body of comprehensive data regarding the spatiotemporal tuning of the primate visual system. These data will be used to further understanding of the mechanisms of sensory processing and will provide insights into pathologies of vision caused by trauma, disease and developmental disorders of the brain. !
The long-term goal of this project is to contribute to the understanding of biological substrates of visual perception. Detailed knowledge of normal functions of visual cortex shall provide insights into neural events that underlie visual sensitivity and the effects of visual experience, which will ultimately aid the treatment and prevention of neurologic and neuropsychiatric disorders of vision. These aims are pertinent to development and use of prosthetic and behavioral therapies for the visually handicapped.