Experimental studies on figural after-effects in Japan.

A shape-contrast effect for briefly presented stimuli.

“…A pure shape interaction, by definition, should not depend on the retinal coordinates of the interacting shapes. A shapecontrast effect should also occur across large distances, in contrast to figural aftereffects, which decay sharply with distance, the optimum distance ranging from 8' to 3 °, as reported in 13 studies (e.g., Fox, 1951;Kohler & Wallach, 1944;Sagara & Ohyama, 1957).…”

“…Adapting to a grating of a certain spatial frequency makes a test grating of a slightly lower spatial frequency appear even coarser, and that of a slightly higher spatial frequency appear even finer2--the size/spatial-frequency aftereffect (e.g., Blakemore & Campbell, 1969;Blakemore, Nachmias, & Sutton, 1970). Adapting to a stimulus in one location makes a test stimulus presented slightly away from it appear even further awaymthe figural aftereffect (e.g., Kohler & Wallach, 1944;Sagara & Ohyama, 1957). Finally, prolonged viewing of one direction of motion makes a stationary stimulus appear to be moving in the opposite direction--the motion aftereffect (e.g., Anstis & Moulden, 1970;Wohlgemuth, 1911).…”

“…The rest of the article is devoted to (a) providing psychophysical evidence for the existence of nonretinotopic shape-contrast effects above and beyond the effects of low-level contour interactions (figural aftereffects; e.g., Fox, 1951;Kohler & Wallach, 1944;Sagara & Ohyama, 1957) and shape-changing apparent motion (representational mo-1 Similar in the sense that the two stimuli activate a common set of visual neurons.…”

“…Finally, prolonged viewing of one direction of motion makes a stationary stimulus appear to be moving in the opposite direction--the motion aftereffect (e.g., Anstis & Moulden, 1970;Wohlgemuth, 1911). An important characteristic of these aftereffects is that they are strictly local (except for some size aftereffects--e.g., Ohyama, 1954Ohyama, , 1956Sagara & Ohyama, 1957--and some motion aftereffects---e.g., Culham & Cavanagh, 1995;von Griinau & Dube, 1992); test stimuli have to be presented at (or very near) the site of adaptation in order to obtain the effect.…”

One line decreases the visibility of a simultaneous identical distant second line

“…In addition, it replaces assimilation with the aftereffect type of contrast (Brigell & Uhlarik, 1979;Jordan & Uhlarik, 1985;R. H. Pollack, 1964;Sagara & Oyama, 1957).…”