Functional Distribution in Area VI Revealed by Spatially Uniform Stimuli

摘要

We measured responses to pure luminance changes in area VI using functional magnetic resonance imaging. We fully dilated the subjects' pupils with a mydriatic agent; placed semitransparent, hemispheric covers over the subjects' eyes; and varied luminance levels of stimuli gradually or instantaneously. We found that the profile of cortical responses varied at about 10 degrees of eccentricity on the representation in area VI despite the use of uniform achromatic stimuli. This variation was possibly caused by differences between response profiles in the central and peripheral zones of the retina. Our results might reflect the functional distribution of retinal ganglion cell projections.