The Exceptionality of Deafness

Abstract

Deafness represents another area of exceptional presentation potentially important to the development of cognition. Deaf people can observe. However, to refresh the readers memory, in the above discussion of the neuroanatomic organization of large scale brain systems, evidence was reviewed that auditory processes were organized within the functional connectivity profiles of the ventral (VAN) and dorsal (DAN) attention networks. The visual network (VAN), anchored in the occipital lobes, supports the activities of both of these networks. In a review of structural and functional neuroimaging studies, Vaidya summarized the frequent anomalies observed in medial occipital regions in individuals diagnosed with ADHD [274]. There are direct auditory projections to area V1, a medial region of the occipital lobes. As stated above, medial occipital regions are robustly activated on neuropsychological tasks of verbal WM, even though this activity cannot be explained on the basis of “visual processing.” V1 is the first brain region to receive “visual” projections from the lateral geniculate nucleus of the thalamus, so within the cortex, this is the well documented region where vision begins [165]. V1 has been traditionally understood as solely related to “visual processing.” Multimodal association areas of the parietal lobes, unequivocally involved in the cognitive control functions of FPN, also receive projections from both visual and auditory information processing systems. It has been proposed that auditory input implicitly evokes images to orient, focus, and guide attention [61, 65, 66]. This raises suspicion about whether or not deafness is associated with anomalies in attention and other aspects of cognition.