title: Hemispheric asymmetries in subcortical visual and auditory relay structures in congenital deafness.
abstract: Neuroplasticity - the capacity of the brain to change as a response to internal and external pressures - has been studied from a number of different perspectives. Perhaps one of the most powerful models is the study of populations that have been congenitally deprived of a sense. It has been shown that the right Auditory Cortex (AC) of congenitally deaf humans is neuroplastically modified in order to represent visual properties of a stimulus. One unresolved question is how this visual information is routed to the AC of congenitally deaf individuals. Here, we performed volumetric analysis of subcortical auditory and visual brains regions - namely the thalamus (along with three thalamic nuclei: the pulvinar, the lateral geniculate nucleus and the medial geniculate nucleus), and the inferior and superior colliculi - in deaf and hearing participants in order to identify which structures may be responsible for relaying visual information toward the altered AC. Because there is a hemispheric asymmetry in the neuroplastic changes observed in the AC of the congenitally deaf, we reasoned that subcortical structures that also showed a similar asymmetry in their total volume could have been enlisted in the effort of relaying visual information to the neuroplastically altered right AC. We show that for deaf, but not for hearing individuals, the right thalamus, right lateral geniculate nucleus and right inferior colliculus are larger than their left counterparts. These results suggest that these subcortical structures may be responsible for rerouting visual information to the AC in congenital deafness.
authors.affiliation: Proaction Laboratory, Faculty of Psychology and Education Sciences, University of Coimbra, 3001-802, Coimbra, Portugal.|Faculty of Psychology and Education Sciences, University of Coimbra, Coimbra, Portugal.|CINEICC, Faculty of Psychology and Education Sciences, University of Coimbra, Coimbra, Portugal.
authors.forename: L
authors.initials: L
authors.lastname: Amaral
authors.affiliation: Proaction Laboratory, Faculty of Psychology and Education Sciences, University of Coimbra, 3001-802, Coimbra, Portugal.|Faculty of Psychology and Education Sciences, University of Coimbra, Coimbra, Portugal.|Neuropsychophysiology Laboratory, Research Center in Psychology, School of Psychology, University of Minho, Minho, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Ganho-Ávila
authors.affiliation: Social and Cognitive Neuroscience Laboratory and Developmental Disorders Program, Center for Health and Biological Sciences, Mackenzie Presbyterian University, Sao Paulo, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Osório
authors.affiliation: Proaction Laboratory, Faculty of Psychology and Education Sciences, University of Coimbra, 3001-802, Coimbra, Portugal.|Faculty of Psychology and Education Sciences, University of Coimbra, Coimbra, Portugal.
authors.forename: M J
authors.initials: MJ
authors.lastname: Soares
authors.affiliation: Department of Psychology and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China.
authors.forename: D
authors.initials: D
authors.lastname: He
authors.affiliation: Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY, USA.
authors.forename: Q
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY, USA.|Center for Visual Science, University of Rochester, Rochester, NY, USA.|Department of Neurosurgery, University of Rochester, Rochester, NY, USA.
authors.forename: B Z
authors.initials: BZ
authors.lastname: Mahon
authors.affiliation: Neuropsychophysiology Laboratory, Research Center in Psychology, School of Psychology, University of Minho, Minho, Portugal.|Bouvé College of Health Sciences, Northeastern University, Boston, MA, USA.|Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: O F
authors.initials: OF
authors.lastname: Gonçalves
authors.affiliation: Neuropsychophysiology Laboratory, Research Center in Psychology, School of Psychology, University of Minho, Minho, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Sampaio
authors.affiliation: Department of Psychology and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China.|PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, China.|Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.
authors.forename: F
authors.initials: F
authors.lastname: Fang
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Bi
authors.affiliation: Proaction Laboratory, Faculty of Psychology and Education Sciences, University of Coimbra, 3001-802, Coimbra, Portugal. jorgealmeida@fpce.uc.pt.|Faculty of Psychology and Education Sciences, University of Coimbra, Coimbra, Portugal. jorgealmeida@fpce.uc.pt.|CINEICC, Faculty of Psychology and Education Sciences, University of Coimbra, Coimbra, Portugal. jorgealmeida@fpce.uc.pt.
authors.forename: J
authors.initials: J
authors.lastname: Almeida
mesh_terms: D001303:Auditory Cortex / Q000503:physiopathology*; D001931:Brain Mapping; D003638:Deafness / Q000151:congenital*; D006319:Hearing Loss, Sensorineural / Q000151:congenital*; D006801:Humans; D013477:Superior Colliculi / Q000503:physiopathology; D013788:Thalamus / Q000503:physiopathology; D014793:Visual Cortex / Q000503:physiopathology; D055815:Young Adult
keywords: auditory cortex; neuroimaging; neuronal plasticity; ocular vision; thalamus