Abstract
What role does early visual experience play in the development of the visual cortex? Animal models have demonstrated that transient visual deprivation early in life permanently alters the response properties of neurons in the visual cortex (Wiesel & Hubel, 1965). In humans, studies with blind adults suggest a critical role of early visual experience in shaping the visual cortex. Early but not late onset of blindness causes a massive reduction of grey and white matter volume in the early visual areas (Noppeney, 2007). However, it remains unclear if a transient period of postnatal visual deprivation is sufficient to trigger a long-lasting reorganization of the visual cortex. Here, we obtained high-resolution anatomic MRI scans from a unique cohort of adult patients (n=10) who were deprived of all patterned visual input early in life (mean length of visual deprivation=143 days, range=65-238 days) as a result of congenital dense central cataracts in both eyes. Compared to age and sex matched controls (n=19), the cataract-reversal patients showed increased cortical thickness in the left pericalcarine sulcus and right parstriangularis (ps< 0.001) and decreased cortical thickness in the left lingual gyrus, left superiortemporal sulcus, right temporal-parietal junction, right isthmuscingulate, right parsopercularis, and right lingual gyrus (ps< 0.001). Within the visual cortex, such changes seem to be reciprocal: the thickening in the left pericalcarine sulcus was highly correlated with the thinning in the left lingual gyrus in cataract-reversal patients (r=-0.59, p=0.036) but not in controls (r=-0.22, p=0.18). The reduced visual acuity of cataract-reversal patients could not account for the changes in cortical thickness in any of these areas. Thus, early visual deprivation does trigger a long-lasting cortical reorganization, possibly through competitive interactions among cortical regions.
Meeting abstract presented at VSS 2016