Examined the conditions under which infants employ (1) spatial codes respondent to objects central to their visual field and (2) spatial codes respondent to objects peripheral to their visual field. (DB)

In Experiment I, 24 preschoolers were tested on left-right, vertical-horizontal, and mirror-image oblique discriminations under essentially context-free conditions. Experiment II contrasted children's performance under context-free conditions with their ability to discriminate orientation in the presence of external visual cues. (RH)

Investigated the nature of spatial representations underlying simple visually guided actions with 3- and 7-month-old infants. Saccades in older infants were executed within body-centered spatial coordinates that account for intervening eye movements, whereas younger infants responded according to the target's retinocentric locations without…

Comparison of 2 totally blind, 2 visually impaired, and 9 normally sighted children (ages 5-8) on tasks of visual perspective taking found that the totally blind children were older than the other children when they mastered the tasks, made the highest percentage of errors before mastery, and made different errors. (Author/DB)

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)

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…

A rather consistent finding in studies of perceived (imagined) compared to actual movement in a reaching paradigm is the tendency to overestimate at midline. Explanations of such behavior have focused primarily on perceptions of postural constraints and the notion that individuals calibrate reachability in reference to multiple degrees of freedom,…

Williams syndrome (WS) is a rare genetic disorder that results in severe visual-spatial cognitive deficits coupled with relative sparing in language, face recognition, and certain aspects of motion processing. Here, we look for evidence for sparing or impairment in another cognitive system--object recognition. Children with WS, normal mental-age…

Humans see whole objects from input fragmented in space and time, yet spatiotemporal object perception is poorly understood. The authors propose the theory of spatiotemporal relatability (STR), which describes the visual information and processes that allow visible fragments revealed at different times and places, due to motion and occlusion, to…

The present study examined spatial learning in goldfish using a new apparatus that was an open-field circular pool with latticed holes. The subjects were motivated to reach the baited hole. We examined gustatory cues, intramaze cues, the possibility that the subject could see the food, etc. In Experiment 1, the position of the baited hole was…

The detection or discrimination of the second of 2 targets in a rapid serial visual presentation (RSVP) task is often temporarily impaired-a phenomenon termed the attentional blink. This study demonstrated that the attentional blink also affects localization performance. Spatial cues pointed out the possible target positions in a subsequent visual…

Semantic influences on attention during the 1st fixation on a scene were explored in 3 experiments. Subjects viewed briefly presented scenes; following scene presentation, a spatial probe was presented at the location of an object whose identity was consistent or inconsistent with the scene category. Responses to the probe served as an index of…

A visual short-term memory task was more strongly disrupted by visual than spatial interference, and a spatial memory task was simultaneously more strongly disrupted by spatial than visual interference. This double dissociation supports a fractionation of visuospatial short-term memory into separate visual and spatial components. In 6 experiments,…

The Sprague effect is well-established--small tectal lesions restore visual orientation in the hemianopic field of animals with extensive unilateral geniculo-striate lesions. Studies of human midbrain visual functions are rare. This man with a midbrain tumour developed left-neglect through subsequent right frontal damage. Bilateral orientation…