Rod-isolation techniques show that light-adapted human rods detect flicker frequencies as high as 28 hertz, and that the function relating rod critical flicker frequency to stimulus intensity contains two distinct branches. (MLH)

Reports effects of context that are entirely perceptual. Visual discrimination was enhanced when line segments were flashed in a region that was perceived as a figure. Discrimination was substantially degraded when the same region was seen as ground although the physical stimulus remained identical throughout figure-ground reversals. (Author/JN)

Research shows that children of about 10 years can remember photographs of faces upside down almost as well as those shown upright and are easily fooled by simple disguises. This ability to encode orientation-specific configurations of a face may reflect maturational changes in the right cerebral hemisphere. (MLH)

Results of discriminating and monitoring tasks indicate that performance deteriorates over time when a specific object must be distinguished from previously presented nonspecific objects in a display which changes quickly. The results offer a basis for distinguishing between perceptual and response processes underlying the vigilance decrement.…