Contrast thresholds for sine-wave gratings of spatial frequencies of 2, 4, 12, and 16 cycles per degree were determined for normal and disabled readers at a range of stimulus durations. The differences in sensitivity pattern across spatial frequencies was greatest at stimulus durations approximately equal to fixation durations during reading.…

Small graphic changes made in normal letters of the alphabet changed the similarity relations among those letters. Children and adults classified letters of this distinctive font faster and with fewer errors than they did normal letters. Relations between letters in the stimulus set determined how difficult any particular letter was to classify.…

The effects of stimulus duration and contrast on duration of visible persistence as a function of spatial frequency were investigated in normal and specific-reading-disabled children. Results suggest that disabled readers have different contrast processing at low and high spatial frequencies and indicate differences between readers in basic visual…

Summarizes the anatomical, physiological, and psychological evidence related to the primate visual system. States that comparison of perceptual abilities with the electrophysiological properties of neurons may help deduce functions of visual areas. (RT)

Investigates the influence of linguistic structure on non-linguistic cognition by comparing Russian and English behavior on tasks involving the color blue. Russians, who differentiate this region into "dark blue" and "light blue," were expected to separate blues more often than English subjects for whom the colors belong to one lexical category.…