Stereopsis-processing regions in the human parieto-occipital cortex.

We performed fMRI on the human parieto-occipital cortex in order to identify the neural processing regions of stereopsis. Visual stimulation for stereopsis was performed with a random-dot stereogram displayed in the image guides of a new binocular visual stimulation device that we developed. Interestingly, regions from the dorsal portion of the occipital lobe to the superior parietal lobule were activated by binocular disparity, while the inferior parietal lobule was not activated. Moreover, these regions were shown as dominant in the right hemisphere. Functional brain mapping revealed that the processing regions of stereopsis were dorsally located in parieto-occipital cortex, and that the superior parietal lobule is an important region for neural processing of human stereopsis.