A short period of visual deprivation at birth triggers long-lasting crossmodal reorganization of the occipital cortex in humans
25.13, Saturday, 16-May, 5:15 pm - 6:45 pm, Talk Room 1
Olivier Collignon1, Giulia Dormal2, Adelaide de Heering3, Franco Lepore2, Terri Lewis3, Daphne Maurer3; 1Centre for Mind/Brain Science (CIMeC), University of Trento, Italy, 2Centre de Recherche en Neuropsychologie et Cognition (CERNEC), Université de Montréal, Canada, 3Visual Development Lab, Department of Psychology, Neuroscience and Behaviour, McMaster University, Canada.
The study of sensory deprivation is a striking model to reveal the role experience plays in sculpting the functional architecture of the brain. Here we used functional Magnetic Resonance Imaging to characterize brain responses to auditory stimuli in 11 adults who had been deprived of all patterned vision at birth by dense congenital cataracts in both eyes until they were removed surgically at 9 to 238 days of age. When compared to a control group with typical vision, the cataract-recovery group showed enhanced auditory-driven activity in two focal bilateral visual regions (the superior occipital gyrus and the cuneus) classically considered retinotopic. The crossmodal activation of occipital regions correlated neither with visual acuity nor with the duration of deprivation in the cataract-recovery group. A combination of dynamic causal modeling with Bayesian model selection indicated that this auditory-driven activity in the occipital cortex was better explained by direct cortico-cortical connections with primary auditory cortex than by subcortical reorganizations. These results demonstrate that a short period of visual deprivation during the early sensitive period of brain development leads to enduring large-scale crossmodal reorganization of the brain circuitry typically dedicated to vision.