Figure 9.

Adapting the disparity of a reversed-depth plaid. (A) Sinusoidal gratings with negative (“near”) disparity when cross-fused. (B) Sinusoidal plaid with positive (“far”) disparity when cross-fused. The plaid is composed of the grating in panel A and a zero-disparity grating with a different orientation. (C) The depth order of the two gratings, as each would appear if displayed individually along with the fixation disk. One grating would appear in front of fixation and the other in the fixation plane. If they were spatially and temporally aligned and given appropriate orientations, they would appear as a coherent plaid behind fixation. Nothing would appear on the near side or in the fixation plane. The “far” horizontal disparity of the plaid could be detected directly or calculated from the disparities of the plaid's 1-D components. An adaptor with “far” disparity would affect the perceived depth of the plaid in the former case; one with “near” disparity would do so in the latter case. Adapting at a “near” disparity with a stimulus having an orientation similar to that of the “near” grating is essential for influencing the perceived “far” depth of the plaid (Farell, 1998).