Perceived tachistoscopic duration and early visual processing in preschool children and adults

Two experiments further explored the Avant et al. (1975) finding that stimulus familiarity influences prerecognition processing to generate differences in the apparent duration of tachistoscopic flashes. The first experiment tested for developmental differences in the effects of upright versus 90°, 180°, and 270° rotations of a single letter or number upon the apparent duration of pre- and postmasked 30- and 50-msec flashes with adults and 4- and 5-year-old children. All age groups judged upright presentations to be of briefer duration. These differences in apparent duration were interpreted to index the automaticity of contacts between stimulus inputs and their memory representations. Failure of the children to recognize the letter and number in any orientation indicates that contact between stimulus inputs and memory representations precedes allocation of attention to the presented stimulus. The second experiment explored the influence of spatial structures which are not coded verbally by testing effects of good and poor dot pattern Gestalts on the apparent duration of tachistoscopic flashes. Adults discriminated between apparent durations of good and poor Gestalts but 4- and 5-year-olds did not. Apparent duration differences in the two experiments showed that spatial pattern structure and familiarity with verbal stimuli influence early visual processing in different ways.