Equiluminous red-green sine-wave gratings were drifted at a uniform rate in the bottom half of a 10-deg field. In the top half of the display was a sinusoidal-luminance grating of the same spatial frequency and 95% contrast that drifted in the opposite direction. Observers, while fixating a point in the display center, adjusted the speed of this upper comparison grating so that it appeared to match the velocity of the chromatic grating below. At low spatial frequencies, equiluminous gratings were appreciably slowed and sometimes stopped even though the individual bars of the grating could be easily resolved. The amount of slowing was proportionally greatest for gratings with slow drift rates. Blue-yellow sine-wave gratings showed similar effects. When luminance contrast was held constant, increasing chrominance modulation caused further decreases in apparent velocity, ruling out the possibility that the slowing was simply due to decreased luminance contrast. Perceived velocity appears to be a weighted average of luminance and chrominance velocity information.

The purpose of this study was to evaluate the gender stereotypes endorsed by elementary and high school students regarding mathematics and language. We developed a questionnaire allowing students to rate mathematics and language as either male or female domains and administered it to a sample of 984 elementary and high school French-speaking Canadian students (Grades 6, 8, and 10). Results showed that, with the exception of Grade 6 boys, students did not believe that mathematics was a male domain, or even conceived of mathematics as a predominantly female domain, suggesting that the traditional stereotype favouring boys in mathematics might have changed over the past few years. Moreover, language was clearly viewed as a female domain. Overall, our findings suggest that boys seem to be in need of encouragement in school, especially regarding language, where the advantage given to girls is particularly salient.

When observers who watched repeated alternations of a red contracting spiral and green expanding spiral were later shown stationary spirals, red and a green the red stationary spiral appeared to be expanding and the green stationary spiral appeared to be contracting. These color-contingent motion after effects complement reports of motion-contingent color aftereffects and suggest that both may reflect adaptation of detectors specific to color and motion.

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Observers adapted to motion by looking at rotating logarithmic spirals. They were tested with a stationary mirror image of the adapting spiral in which all contours were at 90 degrees to those of the first spiral. Motion aftereffects were reported in the contrarotational direction--that is, observers who had seen clockwise rotating motion reported seeing counterclockwise aftereffects. These aftereffects lasted one-third as long as the aftereffects obtained when the adapting spiral was used as the test figure. These two aftereffects were shown to have different storage properties, thereby indexing the operation of at least two different mechanism. We interpret the motion aftereffect that is obtained with the mirror-image stimulus as indicative of the existence of global rotation detectors.

Two fields of random dots that were identical except for a slight shift in a central square region were presented in rapid alternation. This produced a vivid impression of a square moving back and forth above the background. When the kinematogram is presented in equiluminous red/green, the motion of the central region can still be seen, although over a narrower range of alternation rates, interstimulus intervals, and displacements than for black/white presentation. The perception of motion for equiluminous stimuli indicates that colour and motion can be analyzed conjointly by the visual system. However, as originally reported by Ramachandran and Gregory, the segregation of the oscillating central square from the background is lost at equiluminance. This segregation process therefore appears to be colour-blind.

Jones and Holding (1975) showed that orientation-contingent color aftereffects can persist for at least 3 months, but are depleted by repeated testing. We applied the same paradigm to a simple motion aftereffect (MAE) and found that it can persist for up to 1 week and is only slightly diminished by testing. It was further found that simple MAEs appear to persist longer than color-contingent MAEs. although when procedures for inducing and measuring both kinds of aftereffect are equalized, contingent MAEs last longer. Finally, no tendency was found for color-contingent MAEs to diminish with repeated testing. Although both simple and color-contingent MAEs can be relatively persistent, there are certain differences between them. Furthermore, contingent aftereffects should not be considered interchangeable, as there appear to be large differences in the persistence of orientation-contingent color aftereffect and color-contingent MAEs.187