title: Microstructural differences in the thalamus and thalamic radiations in the congenitally deaf.
abstract: There is evidence of both crossmodal and intermodal plasticity in the deaf brain. Here, we investigated whether sub-cortical plasticity, specifically of the thalamus, contributed to this reorganisation. We contrasted diffusion weighted magnetic resonance imaging data from 13 congenitally deaf and 13 hearing participants, all of whom had learnt British Sign Language after 10 years of age. Connectivity based segmentation of the thalamus revealed changes to mean and radial diffusivity in occipital and frontal regions, which may be linked to enhanced peripheral visual acuity, and differences in how visual attention is deployed in the deaf group. Using probabilistic tractography, tracts were traced between the thalamus and its cortical targets, and microstructural measurements were extracted from these tracts. Group differences were found in microstructural measurements of occipital, frontal, somatosensory, motor and parietal thalamo-cortical tracts. Our findings suggest that there is sub-cortical plasticity in the deaf brain, and that white matter alterations can be found throughout the deaf brain, rather than being restricted to, or focussed in the auditory cortex.
authors.affiliation: Cognitive and Perceptual Brain Sciences, 26 Bedford Way, University College London, London WC1H 0AP, UK. Electronic address: c.rebeccalyness@gmail.com.
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Lyness
authors.affiliation: Institute of Child Health, University College London, London WC1N 1EH, UK.
authors.forename: I
authors.initials: I
authors.lastname: Alvarez
authors.affiliation: Cognitive and Perceptual Brain Sciences, 26 Bedford Way, University College London, London WC1H 0AP, UK; Birkbeck, University of London, Malet Street, Bloomsbury, London WC1E 7HX, UK.
authors.forename: Martin I
authors.initials: MI
authors.lastname: Sereno
authors.affiliation: Deafness, Cognition & Language Research Centre, 49 Gordon Square, University College London, London WC1H 0PD, UK; Institute of Cognitive Neuroscience, 17 Queen Square, University College London, London WC1H 3AR, UK.
authors.forename: Mairéad
authors.initials: M
authors.lastname: MacSweeney
mesh_terms: D000328:Adult; D002540:Cerebral Cortex / Q000033:anatomy & histology* / Q000473:pathology; D003638:Deafness / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000033:anatomy & histology / Q000473:pathology; D009473:Neuronal Plasticity / Q000502:physiology*; D013788:Thalamus / Q000033:anatomy & histology* / Q000473:pathology; D066127:White Matter / Q000033:anatomy & histology / Q000473:pathology
keywords: Deafness; Diffusion weighted MRI; Neuroplasticity; Thalamus