Anthony & Jesse

Background

What is Retinotopy?

Early visual areas are organized by a principle known as retinotopy. The basic idea behind this principle is that stimulation of adjacent regions of the visual field activate adjacent locations on the cortical surface, and specific locations in these areas respond to stimulation only in particular parts of the visual field. In addition, the preference for particular locations in the visual field across the cortical surface is highly consistent across individuals and can be mapped with fMRI.

Discovery of Visual Field Maps

In the early 1900s, Inouye and Holmes are the first to discover that the location of lesions to primary visual cortex (V1) is related to visual field deficits. For instance, damage to the V1 in the left hemisphere results in impaired vision in the right visual field and damage to the anterior portion of V1 results in impaired vision at peripheral locations in the visual field. Electrophysiological records in the 1940s identified additional field maps adjacent to V1 including V2 and V3. Each map contains a representation of the entire visual field. However, transitions between maps are smooth in that the areas near the boundaries of field maps both respond to nearby locations in the visual field.