Assessed 13- and 20-week-olds infants' discrimination between shearing stimuli, in which columns of dots move vertically on a screen at different velocities, and foil stimuli, in which all dots move at the same velocity. Results revealed the threshold levels of dot velocity in shearing stimuli at which discrimination occurred. (BC)

A study examined how well children could discriminate matches from nonmatches of multicomponent stimuli within the prototypic mental rotation task and how long it would take them to make such discriminations. The goal was to determine whether children are differentially sensitive to the various spatial features of visual stimuli and whether…

Two experiments found that (1) by age 8 months infants perceived that leaning extends their effective reaching space to grasp objects; (2) by 10 months they perceived the effective limits of leaning and reaching; and (3) by 12 months they began to perceive how this space may be extended by a mechanical aid. (MDM)

Three experiments investigated children's understanding of inference as a knowledge source. Most 4- to 6-year-olds did not rate a puppet as more certain of a toy's color after the puppet looked at the toy or inferred its color than they did after the puppet guessed the color. Most 8- and 9-year-olds distinguished inference and looking from…

Examined visual search for compound patterns in 6-, 8-, 10-, and 22-year-olds. Found large improvements with age in search rate for long-range targets; search rate for short-range targets was fairly constant across age. This pattern held regardless of ease of perceptual access to target, supporting the hypothesis of different processes involved at…

Investigated 4- and 7-month-olds' perception of transparency, using computer-generated achromatic or color displays depicting a semitransparent box occluding the center of a rod. Found that 4-month-olds indicated perception of transparency in color but not in achromatic displays. Seven-month-olds showed some evidence of transparency perception in…

The effect of element density on selective orienting was examined in 2 experiments with 2- and 4.5-month-old infants. Selective visual orienting to a singleton oscillating target that appeared with other static bars was used to study the effects of element density. Increasing the set size and density of the static bars decreased selective…

Perceptual grouping by luminance similarity and by proximity was investigated in infants with Williams syndrome (WS) aged between 6 and 36 months (visit 1, N=29). WS infants who were still under 36 months old, 8 months later, repeated the testing procedure (visit 2, N=15). Performance was compared to typically developing (TD) infants aged from 2…

The primary purpose of this study was to examine whether a general perceptual model developed by Vitz and Todd (1971), capable of dealing with multiple determinants of attending, is useful for understanding infant attending. The model, previously used in research with adults, assumes that perception can be represented as a stochastic sampling…

In this study, developmental changes in duration of the icon (visual sensory store) were investigated with three converging tachistoscopic tasks. (1) Stimulus interuption detection (SID), a variation of the two-flash threshold method, was performed by 29 first- and 32 fifth-graders, and 32 undergraduates. Icon duration was estimated by stimulus…

This study investigated the way 12 infants, aged 1 month and 2 months, scanned the still and expressionless faces of their mothers, of strange women, and of strange men. Each infant was placed in a padded head-restraining cradle under a half-silvered mirror which was angled at 45 degrees to enable the child to view an adult's face at an optical…

The effects of perceptual and cognitive factors on information processing in visual periphery were studied in 5- and 8-year-old children and in adults. Subjects judged either the similarity (Study 1) or identity (Study 2) of geometric forms. (Author/SB)