Accession Number : AD0783694

Title :   Critical Duration for Resolution of Acuity Targets.

Descriptive Note : Technical rept.,

Corporate Author : ROCHESTER UNIV N Y CENTER FOR VISUAL SCIENCE

Personal Author(s) : Brown,John Lott ; Black,John E.

Report Date : JUL 1974

Pagination or Media Count : 30

Abstract : Line grating patterns which illuminated a 1 degree test field centered 1.5 degree from the fovea were presented in either of two orientations for various flash durations of from 2 to 1000 msec. Grating pattern frequencies of from 2 to 10 cycles per degree were used. Luminance thresholds for correct identification of grating orientation were measured in the dark adapted eye and against mesopic and low photopic background luminances. The critical duration within which temporal summation occurred was most significantly influenced by level of adaptation, being longer the lower the adaptation level. This was true for all spatial frequencies investigated, including the highest for which discrimination always depended upon cones. (Modified author abstract)

Descriptors :   *Visual acuity, *Target recognition, Visual perception, Adaptation(Physiology), Thresholds(Physiology), Luminescence

Subject Categories : Psychology
      Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE