Functional separation of global and local stereopsis investigated by cross-adaptation.

Reports that brain lesions may differentially affect global and local stereopsis suggest that anatomically separate mechanisms underlie these two functions. We demonstrate here that adaptation to global stereograms induces an after-effect on local stereopsis as well as on global stereopsis, showing that the two mechanisms cannot be entirely separate. We suggest that global stereopsis depends upon an interaction between primary visual area V1 and higher brain areas such as inferotemporal cortex.