One of the fundamental tenets of sensory biology is that sensory systems adapt to environmental change. It has been argued that adaptation should have the effect of optimizing sensitivity to the new environment. To make this premise concrete and precise, the proposed research builds on a normative theory of visual motion perception, which argues that the visual system will adapt optimally by balancing stimulus and measurement uncertainties. This theory makes predictions about visual spatiotemporal sensitivity as a function of environmental statistics: Adaptive optimization should be manifested as a change in spatiotemporal sensitivity for an observer and for the underlying motion-sensitive neurons. The proposed research will test these predictions. The effects of adaptation on visual sensitivity will be examined in the context of the neuronal representation of speed of visual motion. Adaptation using specific speeds will be used as a means to effect a change in environmental statistics. Both perceptual and neuronal consequences of this adaptation will be recorded, with the expectation that sensitivity changes will reflect the modeled process of optimization. The proposed research constitutes a richly interwoven collection of psychophysical, neurophysiological and theoretical approaches to the topic of visual adaptation. Experiments have been designed to yield an unprecedented body of comprehensive data bearing on the spatiotemporal properties of the primate visual system and the effects of environmental change. These data will be used to further understanding of the phenomenology and mechanism of adaptation.
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 impaired.
|Zharikova, Aleksandra; Gepshtein, Sergei; van Leeuwen, Cees (2017) Paradoxical perception of object identity in visual motion. Vision Res 136:1-14|
|Snider, Joseph; Lee, Dongpyo; Poizner, Howard et al. (2015) Prospective Optimization with Limited Resources. PLoS Comput Biol 11:e1004501|
|Sejnowski, Terrence J; Poizner, Howard; Lynch, Gary et al. (2014) Prospective Optimization. Proc IEEE Inst Electr Electron Eng 102:|
|Gepshtein, Sergei; Li, Xiaoyan; Snider, Joseph et al. (2014) Dopamine function and the efficiency of human movement. J Cogn Neurosci 26:645-57|
|Jurica, Peter; Gepshtein, Sergei; Tyukin, Ivan et al. (2013) Sensory optimization by stochastic tuning. Psychol Rev 120:798-816|
|Gepshtein, Sergei; Lesmes, Luis A; Albright, Thomas D (2013) Sensory adaptation as optimal resource allocation. Proc Natl Acad Sci U S A 110:4368-73|
|Wagemans, Johan; Feldman, Jacob; Gepshtein, Sergei et al. (2012) A century of Gestalt psychology in visual perception: II. Conceptual and theoretical foundations. Psychol Bull 138:1218-52|
|Vidal-Naquet, Michel; Gepshtein, Sergei (2012) Spatially invariant computations in stereoscopic vision. Front Comput Neurosci 6:47|