Early blindness shapes cortical representations of auditory frequency within auditory cortex.

Early loss of vision is classically linked to large-scale cross-modal plasticity within occipital cortex. Much less is known about the effects of early blindness on auditory cortex. Here, we examine the effects of early blindness on the cortical representation of auditory frequency within human primary and secondary auditory areas using functional magnetic resonance imaging (fMRI). We observe that 4 individuals with early blindness (2 females), including a subset of 5 individuals with anophthalmia (1 female), a condition in which both eyes fail to develop, have lower response amplitudes and narrower voxel-wise tuning bandwidths compared to a group of typically sighted individuals. These results provide some of the first evidence in human participants for compensatory plasticity within non-deprived sensory areas as a result of sensory loss.SIGNIFICANCE STATEMENTEarly blindness has been linked to enhanced perception of the auditory world, including auditory localization and pitch perception. Here we used functional magnetic resonance imaging to compare neural responses to auditory stimuli within auditory cortex across sighted, early blind, and anophthalmic individuals, in whom both eyes fail to develop. We find more refined frequency tuning in blind subjects, providing some of the first evidence in human subjects for compensation within non-deprived primary sensory areas as a result of blindness early in life.