Assesses performance of 9-, 13-, and 20-year-olds on 3,840 trials of a mental rotation task in which subjects judged if pairs of stimuli presented in different orientations were identical or mirror images. Results are discussed in terms of possible mechanisms underlying the impact of practice. (Author/NH)

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…

Three experiments with observers aged 6 to 21 years of age examined the integration of shape information over successive glances. Results indicated age-related improvements in the sequential integration of shape information, both when integration occurs through successive glimpses over space and when information is separated only in time. (HOD)

Experiments were conducted on the speed of encoding differences between 15 school-age individuals with and 15 individuals without mental retardation, while retaining a full memory load or half memory load. Subjects with mental retardation allocated fewer attentional resources to encoding, even though encoding may require more of their resources…

Examines interactions between timing accuracy and muscular parameters in children aged five who performed a visuomotor game. Five images were successively presented on a television display at precisely timed intervals for a total period of 11 seconds. Results suggest that timing accuracy is dependent on action-produced sensory cues. (RWB)

The effects of different types of feedback in computer assisted instruction were studied in 30 college students with different cognitive styles. The program, written in Apple Pilot and administered on an Apple IIE microcomputer, consisted of 16 problem solving tasks; for each, a graphic display and a textual question were presented. Two feedback…