Abstract
A recent study reported that individuals with central retinal lesions due to macular degeneration (MD) showed grey matter reduction in “foveal” cortex, apparently due to the loss of bottom-up input. Here we ask whether similar structural changes are found in individuals with loss of bottom-up input due to MD, but who show functional reorganization, in which foveal cortex responds to peripherally presented stimuli. We predicted that if grey matter reduction is driven by cortical deprivation, then such structural changes should not be found in MD individuals who show functional reorganization. As predicted, we found no evidence for grey matter reduction in foveal cortex in these individuals. These findings suggest that reorganization of visual processing (i.e., the activation of foveal cortex by peripheral stimuli) may be sufficient to maintain “normal” cortical structure.
NIH grant EY016559 (NK), and a Kirschstein-NRSA EY017507 (DDD).