Differential activity in Heschl's gyrus between deaf and hearing individuals is due to auditory deprivation rather than language modality.
Sensory cortices undergo crossmodal reorganisation as a consequence of sensory deprivation. Congenital deafness in humans represents a particular case with respect to other types of sensory deprivation, because cortical reorganisation is not only a consequence of auditory deprivation, but also of language-driven mechanisms. Visual crossmodal plasticity has been found in secondary auditory cortices of deaf individuals, but it is still unclear if reorganisation also takes place in primary auditory areas, and how this relates to language modality and auditory deprivation. Here, we dissociated the effects of language modality and auditory deprivation on crossmodal plasticity in Heschl's gyrus as a whole, and in cytoarchitectonic region Te1.0 (likely to contain the core auditory cortex). Using fMRI, we measured the BOLD response to viewing sign language in congenitally or early deaf individuals with and without sign language knowledge, and in hearing controls. Results show that differences between hearing and deaf individuals are due to a reduction in activation caused by visual stimulation in the hearing group, which is more significant in Te1.0 than in Heschl's gyrus as a whole. Furthermore, differences between deaf and hearing groups are due to auditory deprivation, and there is no evidence that the modality of language used by deaf individuals contributes to crossmodal plasticity in Heschl's gyrus.
Deafness, Cognition and Language Research Centre, 49 Gordon Square, University College London, London WC1H 0BT, UK; Linnaeus Centre HEAD, Swedish Institute for Disability Research, Department of Behavioural Sciences and Learning, Linköping University, Sweden. Electronic address: velia.cardin@gmail.com.
Velia
V
Cardin
Experimental Psychology, 26 Bedford Way, University College London, London WC1H 0AP, UK.
Rebecca C
RC
Smittenaar
Deafness, Cognition and Language Research Centre, 49 Gordon Square, University College London, London WC1H 0BT, UK; School of Psychology, University of Crete, Greece.
Eleni
E
Orfanidou
Linnaeus Centre HEAD, Swedish Institute for Disability Research, Department of Behavioural Sciences and Learning, Linköping University, Sweden.
Jerker
J
Rönnberg
School of Psychological Sciences, University of Manchester, Manchester M13 9PL, UK.
Cheryl M
CM
Capek
Linnaeus Centre HEAD, Swedish Institute for Disability Research, Department of Behavioural Sciences and Learning, Linköping University, Sweden.
Mary
M
Rudner
Deafness, Cognition and Language Research Centre, 49 Gordon Square, University College London, London WC1H 0BT, UK.
Bencie
B
Woll
D000328:Adult; D001303:Auditory Cortex / Q000503:physiopathology*; D001931:Brain Mapping; D003638:Deafness / Q000503:physiopathology*; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D008037:Linguistics; D008297:Male; D008875:Middle Aged; D009473:Neuronal Plasticity; D012813:Sign Language
Deafness; Heschl's gyrus; Sign language; Speech; fMRI