Abstract
The retinal image constantly changes due to head, eye and object movement. Yet, perception of three-dimensional structure is strikingly stable. Thus, depth relations have to be bound to a constant for temporal integration. Recent studies show that depth-after-effects do not depend on the stimulated retinal location and can be specific for spatial location or an object property such as colour. We address the extent to which depth relations are encoded bound to figure contour or spatial location.
Observers adapted to a disparity-defined figure in front of a constant background. Next, they indicated whether a test figure was located further form the background than a reference stimulus (two dots). The test stimulus was either the same checkerboard (‘dentical’condition) as the adaptation stimulus, or the inverse checkerboard, which shares only figure contours with the adaptation stimulus but has no surfaces at the same spatial location (‘ontour’condition). If depth relations are bound to spatial location one would expect a depth-after-effect only in the ‘dentical’ condition, but if depth relations are bound to figure contour, a depth-after-effect could occur in both conditions as the figures shared their outline.
Perception of the test figure' distance to the background was biased in the direction opposite to the distance of the adaptation figure (a depth-after-effect) in both the identical and the contour conditions.
From this we conclude that encoding of depth relations can be bound to figure contour. We will proceed to investigate the extent to which the depth-after-effect is specific to the figure contour or figure-ground relations in general.