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Retinotopic Mapping

In some visual areas (e.g., V1 through V5) the neurons are organized in an orderly fashion called topograpphic or retinotopic mapping, in the sense that they form a 2D representation of the visual image formed on the retina in such a way that neighboring regions of the image are represented by neighboring regions of the visual area. However, the retinotopic representation in the cortical areas is distorted. The foveal area is represented by a relatively larger area in V1 than the peripharal areas.

The retinotopic mapping is clearly demonstrated by an experiment by Tootell et al as shown here: ../figures/retinotopicmap.gif

 
Figure: Retinotopic mapping of the visual field (experimental result)

Also note that in this mapping, the upper region of the image is represented by the lower part of the V1 area, and the left side of the image is represented by the V1 area of the right hemisphere, and vice versa:

../figures/retinotopicmap1.gif

 
Figure: Retinotopic mapping of the visual field (illustration)


next up previous
Next: About this document ... Up: The Visual Cortex Previous: Two pathways
Ruye Wang
1999-08-31