Dissociating neural activity associated with the subjective phenomenology of monocular stereopsis: an EEG study
bioRxiv Preprint Server January 30, 2019 Makoto Uji, Ines Jentzsch, James Redburn et al. preprint
The vivid sense of depth and solidity that defines stereopsis is usually attributed to the brain's processing of binocular disparity. However, the same impression can occur when viewing a picture with one eye through a small hole. By measuring EEG brain activity while people looked at images of 2D and 3D shapes under different viewing conditions, a specific pattern of neural activity was identified that accompanied this qualitative depth experience. Only the monocular aperture condition, which produces the strongest depth impression, showed elevated gamma-band synchronization in the parietal cortex when comparing 3D to 2D shapes. This suggests that the subjective experience of stereopsis involves neural processes distinct from those that compute binocular disparity.