The Hierarchical nature of perceiving direction of motion in depth from optic flow

Monocular adaptation to flow fields of optic expansion and contraction juxtaposed on either side of fixation influenced subsequently perceived rotation direction of a figure rotating in depth (kinetic depth effect) about its vertical axis with a normally ambiguous direction. This influence was shown to be asymmetric since adapting to optic expansion produced significantly more aftereffects of translation in depth than did adapting to perceived rotation in depth when viewing a neutral test stimulus. The results are evidence for a hierarchical processing model for the perception of motion in depth from optic flow. Serendipitously, we discovered a new aftereffect from viewing kinetic depth rotation with direction specified by proximity-luminance covariation (PLC). The results and other research are discussed in terms of neural network models with synergistic interactions between levels.