Abstract
In the past two decades, our knowledge of cortical columns in human visual cortex has expanded considerably, thanks to advances in high-resolution functional magnetic resonance imaging (fMRI) techniques and improvements in data processing methods. In the first part of this talk, I will present the recently developed fMRI data processing techniques which have improved our capabilities to visualize cortical columns by reducing the amount of unwanted spatial blurring (Wang et al., 2021). Then, in the second part, I will demonstrate the application of these techniques in revealing the selectivity, spatial distribution, and functional connectivity of cortical columns in human retinotopic visual areas (V1-V4), including those that are involved in color, motion, stereopsis, and shape encoding (Nasr et al., 2016; Tootell and Nasr, 2017; 2020). In the third part of this talk, I will demonstrate the application of these techniques in translational studies. Specifically, I will present striking evidence for the impacts of amblyopia, a disorder caused by the interruption of balanced binocular visual inputs in early stages of life, on the fine-scale organization and the response properties of cortical columns across the retinotopic visual areas. These findings will clarify the neuronal disorders that underlie multiple perceptual impairments in amblyopic individuals including stereoblindness and distorted spatial vision. All in all, the presented findings, most of them still unpublished, will highlight the importance of studying cortical columns in understanding visual perception in humans with normal and impaired vision.