Color-selectivity in simultaneous motion contrast

Abstract

Thirty-two Ss were required to estimate the apparent motion of stationary vertical lines viewed against a background of moving vertical lines when both patterns were seen by the same eye (monoptic conditions) or the center pattern was seen by one eye and the surrounds by the other eye (dichoptic conditions). The stationary lines appeared to be moving from right to left as the surrounds moved left to right. The simultaneous motion contrast found under monoptic conditions was maximal when the center pattern and the surrounds were the same color and was reduced when they differed in color. The surrounds had limited influence on the apparent motion of the center section under dichoptic condition, and the color relationship was no longer important. Related color selectivity has been reported for the motion aftereffect (successive motion contrast), and botb sets of data can be attributed to inhibitory interaction (simultaneous in one case and successive in the other) among neural detectors tuned to wavelength as well as the direction of image motion.

The effect of two types of induced-motion displays on perceived location of the induced target

“…An alternative explanation of our aligned-center results is, however, possible. The target motion seen in an aligned-center display may be an example of simultaneous motion contrast (SMC), an effect attributed to center-surround interaction in a retinal velocity-detecting unit (e.g., Over & Lovegrove, 1973). Evidence suggesting that SMC may be derived from peripheral activity (and is, therefore, presumably different from the centrally determined induced motion) comes from a study showing that when a moving pattern within a stationary aperture is presented to one eye and a stationary target to the other eye, induction of the target does not occur (Day & Dickinson, 1977).…”

Absence of color-selectivity in Duncker-type induced visual movement

“…Although Over and Lovegrove (1973) refer to the effect with grating patterns as simultaneous motion contrast, the conditions for its occurrence are superficially the same as those for induced movement described by Brosgole (1968), Duncker (1929Duncker ( /1938, and Wallach (1959). The stationary target appeared to move when the bars of the target actually moved.…”

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Using a stationary target and moving field, both consisting of gratings of vertical light and dark bars, Over and Lovegrove (1973) reported that, with monoptic viewing, induced target movement is weaker when the light bars of the two components are different in color. This reduction did not occur for dichoptic viewing, for which the aftereffect was almost negligible.

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“…The effect is frequently demonstrated by means of a stationary point enclosed within a rectangular moving frame, but it occurs with a variety of stimulus patterns and movements (Duncker, 1929(Duncker, / 1938Wallach, 1959). Over and Lovegrove (1973) used a small, circular, stationary target centered in a larger circular field. Both target and field consisted of light and dark bars, with those of the latter moving laterally.…”

Color selectivity in motion aftereffect

“…This latter distortion has been attributed to inhibitory interaction between directionally sensitive motion detectors. Over and Lovegrove (1973) suggested that these mechanisms might be color tuned, since simultaneous motion contrast is reduced when the center and the surround gratings differ in color. Day and Dickinson (1977) replicated Over and Lovegrove's results using a similar display, although they found that Dunckertype induced motion was insensitive to the color relationship between juxtaposed stationary and moving components.…”