Preliminary fMRI research of the human brain activation under stereoscopic vision

Binocular disparity is of vital importance in stereoscopic vision. It determines the depth magnitude and effects the impression formation when human watch three-dimensional things. However so far how binocular disparity activates the brain regions hasn´t got consistent conclusions. So a fMRI(functional magnetic resonance imaging) experiment was designed to locate cortex areas related with stereoscopic vision using modified random dot stereogram(RDS) as stimuli. This experiment adopted block design and used SPM8 to analyze the data. The results are: (1) hV3A, LG, hMT/V5, LOS and VIPS being the main activated regions in this experiment.(2) The dorsal stream areas are strongly activated while the ventral stream areas are slightly activated. Thus we inferred that (1) There is no single regions that can account for the stereoscopic depth perception completely. Stereoscopic vision is produced by several regions pulling together. (2)The dorsal stream system plays an important role in processing the stereoscopic vision. This phenomenon is consistent with the functions of the two visual systems. There are some differences between these activating areas and results from previous experiments. Here the activated regions and reasons for the differences are discussed. By comparing these results with other studies, the mechanisms of binocular disparity could be further understood. If the activation areas among people with normal stereoscopic vision could be made clear and definite, it will contribute to screening the amblyopia more easily and efficiently by using fMRI scanning.