At some time during every fixation a decision is made to move the eyes, directing them to a new location in the stimulus array. To understand the eye movement control processes, three general hypotheses concerning the cognitive basis for deciding to move the eyes were investigated: the saccade (movement) initiation time is determined only on the…

A test for sensitivity to binocular disparity and a shape perception test were administered to four-month-olds. Results indicated that disparity-sensitive infants could perceive three-dimensional-object shape from kinetic and binocular depth information. (PCB)

Compares estimates of monocular visual resolution of children 6- to 36-months of age with three psychophysical procedures: the Probabilistic Estimation by Sequential Testing (PEST), a modification of the PEST procedure, and the method-of-constant stimuli. (HOD)

Abilities of individuals (n=42), either with or without mental retardation, to search for and detect changes to naturalistic scenes were investigated. Individuals with mental retardation required more time to detect changes, especially changes of marginal interest. Eye-tracking analysis of six participants suggested that individuals with mental…

Presents four experiments comparing the perceptual span in second-, fourth-, and sixth-grade readers and skilled adult readers. Suggests that the size of perceptual span is variable and influenced by text difficulty. Concludes that the size of perceptual span does not cause slow reading rates in beginning readers. (Author/DR)

This study examined effects of visual impairment on the performance of typical educational tasks requiring visual accommodation to print material at three different distances. Subjects were 18 visually impaired and 19 nonimpaired children (ages 6-10). Findings indicated that visually impaired children exhibited more fixation shifts per task.…

The processing of mental structures in perception appears to be serial, in that viewers can fill in missing parts from an impoverished stimulus following a top down process. To investigate the effects of unfamiliarity, complexity, and legibility on object and layout perception of unfamiliar stimuli, ten subjects were shown one of four ribbon…

Studies the ability of 5-month-old infants to recall temporal information and use temporal organization by training them to fixate a hierarchically structured or unstructured sequence of stimuli which appeared in four spatial positions. Results are interpreted within a temporal organizational framework; infants appear to use organization within…

In the study of perception during reading, the use of eye movement contingent control of the stimulus display has proved to be a useful research technique. With such a system, it is possible to experimentally manipulate, in real time, the characteristics of the stimulus display that is present on selected fixations as reading is in progress and to…

Visual fixations were recorded in newborn, 4-, and 8-week-old human infants as they scanned displays that varied in contour length, size, number, and a new metric, CVAL (based on Contour Variability, Amount and Location). One of the findings was that both contour length and CVAL separately accounted for approximatel1 95 of looking-duration…

A graph is an example of a symbol system which encodes information through the juxtaposition of marks in a two dimensional plane; decoding the meaning of a graph uses specific attributes of the human visual system. This study was undertaken to identify some variables critical to graph interpretation as a first step in designing better curriculum…