Accession Number : ADA131698

Title :   Visual Accommodation, the Mandelbaum Effect, and Apparent Size.

Descriptive Note : Technical rept.,


Personal Author(s) : Benel,Russell Andrew

PDF Url : ADA131698

Report Date : Nov 1979

Pagination or Media Count : 139

Abstract : The literature concerning the resting point for accommodation was reviewed. The physiological and anatomical evidence supporting an intermediate resting position were covered in sufficient detail to provide a context within which the behavioral evidence could be interpreted. The more recent behavioral research provides strong evidence for the intermediate resting position and its pervasive effects on visual information processing. the present study investigates the possible development of a functional metric for the description of stimuli, the effects of varying quantities of interposed texture on the accuracy of accommodation to an adequate target at different optical distances, and shifts in apparent sixe coincident with changes in accommodation. A functional metric based on the slope of the regression line relating accommodation to stimulus presentation distance appears feasible. Further development would be required employing a wider range of objective stimulus characterisitics. As stimulus adequacy (indexed by this functional metric and percent contrast) declined, the ability of these stimuli to influence accommodation away from targets presented at various optical distances declined. The disruption of accommodation is apparently related to stimulus adequacy.

Descriptors :   *Vision, Behavior, Information processing, Stimuli, Targets, Range(Distance), Sizes(Dimensions)

Subject Categories : Psychology

Distribution Statement : APPROVED FOR PUBLIC RELEASE