Affiliations: School of Psychology, Georgia Institute of Technology,
Atlanta, GA, USA | Wallace H. Coulter School of Biomedical Engineering,
Georgia Institute of Technology and Emory University School of Medicine,
Atlanta, GA, USA | Department of Ophthalmology and Emory Eye Center,
Emory University School of Medicine, Atlanta, GA, USA
Note: [] Corresponding author: Eric H. Schumacher, School of Psychology,
Georgia Institute of Technology, 654 Cherry Street, Atlanta, GA 30332, USA.
Tel.: +1 404 894 6067; Fax: +1 404 894 8905; E-mail: eschu@gatech.edu
Abstract: Purpose: Neural evidence exists for cortical reorganization in human
visual cortex in response to retinal disease. Macular degeneration (MD) causes
the progressive loss of central visual acuity. To cope with this, MD patients
often adopt a preferred retinal location (PRL, i.e., a functional retinal area
in their periphery used to fixate instead of the damaged fovea). The use of a
PRL may foster cortical reorganization. Methods: We used fMRI to measure brain activity in calcarine
sulcus while visually stimulating peripheral visual regions in MD patients and
age-matched control participants. Results: We found that visual stimulation of the PRL in MD
patients increased brain activity in cortex normally representing central
vision relative to visual stimulation of a peripheral region outside the
patients' PRL and relative to stimulation in the periphery of age-matched
control participants. Conclusions: These data directly link cortical reorganization
in MD to behavioral adaptations adopted by MD patients. These results not only
confirm that large-scale cortical reorganization of visual processing occurs in
humans in response to retinal disease, but also relate this reorganization to
functional changes in patient behavior.
