Learning to see again: biological constraints on cortical plasticity and the implications for sight restoration technologies

点击翻译按钮获取中文摘要

ABSTRACT The field of sight restoration has made dramatic progress: within a decade, many blind individuals are likely to be offered a wide range of options for sight restoration that depend on widely different technologies, including retinal implants, cortical implants and optogenetics. However, interactions between implant electronics and the underlying neurophysiology of the retina or cortex mean that the vision provided by most of these technologies will differ substantially from normal sight. What role does cortical plasticity play in helping patients make use of this artificial visual input? Over the past 15 years our research group has been generating computational models, developed using a combination of physiological and psychophysical data, which predict the percepts that patients might experience for a variety of sight recovery technologies. We propose to use these models to simulate, within visually normal participants, a critical neurophysiological distortion inherent in many sight restoration technologies: the simultaneous stimulation of on and off cells. Our goal is to see how training with this distorted input alters neural representations in object selective areas such as lateral occipital cortex (LOC). Using fMRI, we will measure neural responses to distorted and undistorted objects, before and after training with distorted input. One possibility is that learning to recognize distorted objects results in distorted object images becoming cues for previously learned neural representations within LOC. The alternative is that this training results in the generation of novel representations within LOC. This work will provide novel insights regarding the fundamental mechanisms of cortical plasticity by asking whether, in adulthood, it is possible to reconfigure the fundamental building blocks of visual perception?