Structural brain changes linked to delayed first language acquisition in congenitally deaf individuals.
Early language experience is essential for the development of a high level of linguistic proficiency in adulthood and in a recent functional Magnetic Resonance Imaging (fMRI) experiment, we showed that a delayed acquisition of a first language results in changes in the functional organization of the adult brain (Mayberry et al., 2011). The present study extends the question to explore if delayed acquisition of a first language also modulates the structural development of the brain. To this end, we carried out anatomical MRI in the same group of congenitally deaf individuals who varied in the age of acquisition of a first language, American Sign Language -ASL (Mayberry et al., 2011) and used a neuroanatomical technique, Voxel-Based Morphometry (VBM), to explore changes in gray and white matter concentrations across the brain related to the age of first language acquisition. The results show that delayed acquisition of a first language is associated with changes in tissue concentration in the occipital cortex close to the area that has been found to show functional recruitment during language processing in these deaf individuals with a late age of acquisition. These findings suggest that a lack of early language experience affects not only the functional but also the anatomical organization of the brain.
Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec, Canada H3A 2B4. Electronic address: sidonie.p@gmail.com.
Sidonie
S
Pénicaud
Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec, Canada H3A 2B4. Electronic address: denise.klein@mcgill.ca.
Denise
D
Klein
Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec, Canada H3A 2B4. Electronic address: robert.zatorre@mcgill.ca.
Robert J
RJ
Zatorre
Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec, Canada H3A 2B4. Electronic address: jen-kai.chen@mcgill.ca.
Jen-Kai
JK
Chen
Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec, Canada H3A 2B4.
Pamela
P
Witcher
McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada H3A 2B4. Electronic address: krista.hyde@mail.mcgill.ca.
Krista
K
Hyde
Department of Linguistics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA. Electronic address: rmayberry@ucsd.edu.
Rachel I
RI
Mayberry
D000328:Adult; D000367:Age Factors; D001921:Brain / Q000473:pathology*; D003638:Deafness / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007804:Language Development; D008297:Male; D008875:Middle Aged; D012813:Sign Language