Showing papers by "Stuart Anstis published in 1974"

Movement aftereffects contingent on binocular disparity.

Abstract: Five subjects adapted for 30 min to a textured disc lying in front of the fixation point with 0·1 deg(1) crossed disparity, which rotated clockwise at 4 rev/min, alternating with a disc behind the fixation point, with 0·1 deg of arc uncrossed disparity, which rotated anticlockwise. A stationary test field then appeared to rotate anticlockwise when it lay in front of the fixation point, and clockwise when it lay behind. Conversely, a test field in the plane of fixation briefly appeared to lie a few millimetres behind the fixation plane when it rotated clockwise, and in front when it rotated anticlockwise.The movement aftereffect contingent on disparity reappeared each time the test disparity was reversed, but the total duration of each successive aftereffect in the series decreased exponentially with elapsed time. Movement aftereffects contingent on disparity were very much stronger than those contingent on colour and won out over them when disparity was pitted against colour.

Size adaptation to visual texture and print: evidence for spatial-frequency analysis.

Abstract: The visual system can adapt to the size of print or to the grain size of textures like sandpaper and shows cross-adaptation of print to sandpaper and vice versa. These aftereffects are compared to the well-known shifts in apparent spatial frequency produced by adaptation to gratings, which also show cross-adaptation. Probably, print and sandpaper are analyzed at least partly in terms of their spatial-frequency components.