Figure 3.
Illustration of the spatial layout and temporal sequence of the two measurement conditions. In one case (top), the adapt and test images were alternated in the same centrally fixated field. Observers adjust the contrast of the test image. In the second case (bottom), the adapt and test were again alternated in the same field shown to one side of fixation. The contrast of the test remained fixed, and was matched by instead adjusting the contrast of a matching stimulus shown in a field on the other side of fixation.