Digital image processing of functional magnetic resonance images to identify stereo-sensitive cortical regions using dynamic global stimuli

Abstract

Functional magnetic resonance images (fMRI) were analyzed to investigate the cortical regions involved in stereoscopic vision using red/green anaglyphs to present random dot stereograms. Two experiments were conducted both of which required high attentional demands. In the first experiment the subjects were instructed to follow the path of a square defined by depth and moving in the horizontal plane contrasted with a similar sized square defined by a slight difference in luminance. Three main regions were identified V3A, V3B and BA7. To test that the observed activations were not produced by the pursuit eye movements, a second experiment required the subjects to fixate whilst a shape was presented in different random orientations. Our results suggests that areas V1, V3A and precuneus are involved in stereo disparity processing. We hypothesise that the activation of the V3B region was produced by the second order motion component induced by the spatio-temporal changes in disparity. © Springer-Verlag Berlin Heidelberg 2004.