What and how the deaf brain sees
Document Type
Article
Publication Date
1-1-2018
Journal
Journal of Cognitive Neuroscience
Volume
31
Issue
8
First Page
1091
Last Page
1109
URL with Digital Object Identifier
10.1162/jocn_a_01425
Abstract
�Over the past decade, there has been an unprecedented level of interest and progress into understanding visual processing in the brain of the deaf. Specifically, when the brain is deprived of input from one sensory modality (such as hearing), it often com-pensates with supranormal performance in one or more of the intact sensory systems (such as vision). Recent psychophysical, functional imaging, and reversible deactivation studies have con-verged to define the specific visual abilities that are enhanced in the deaf, as well as the cortical loci that undergo crossmodal plasticity in the deaf and are responsible for mediating these superior visual functions. Examination of these investigations reveals that central visual functions, such as object and facial discrimination, and peripheral visual functions, such as motion detection, visual localization, visuomotor synchronization, and Vernier acuity (measured in the periphery), are specifically enhanced in the deaf, compared with hearing participants. Furthermore, the cortical loci identified to mediate these functions reside in deaf auditory cortex: BA 41, BA 42, and BA 22, in addition to the rostral area, planum temporale, Te3, and temporal voice area in humans; primary auditory cortex, anterior auditory field, dorsal zone of auditory cortex, auditory field of the anterior ecto-sylvian sulcus, and posterior auditory field in cats; and primary auditory cortex and anterior auditory field in both ferrets and mice. Overall, the findings from these studies show that cross-modal reorganization in auditory cortex of the deaf is responsible for the superior visual abilities of the deaf.