Abstract
Purpose: :
Sex differences in sensory functions are important for understanding neural development. However, sex differences in vision have not been studied widely, perhaps because large samples and precise methods are needed to verify them. We report such differences for large groups from a battery of visual tests.
Methods: :
Participants, aged 16–69 years, tested with best optical correction; subset of young adults, whose thresholds were within our norms, tested on all functions to examine possible correlations. Functions: spatio–temporal contrast sensitivity (30 sine gratings –– 6 spatial x 5 temporal frequencies), stereopsis (dynamic random–dot stereograms; crossed and uncrossed acuities and extents of Panum’s area), motion (displacement of random–dot array; Dmin and Dmax), and vernier acuity tested with computer–generated displays (forced–choice; QUEST, 99% confidence). Color appearance of equiluminant monochromatic lights measured with hue and saturation scaling.
Results: :
(i) Contrast sensitivity: color–abnormal males have higher sensitivity than color–normal males over most of the spatio–temporal surface; color–normal males have higher sensitivity than females at high spatial frequencies for all temporal modulation rates. (ii) Stereopsis: males have lower thresholds for crossed and uncrossed disparities; no differences in extent of Panum’s area. (iii) Motion: males have much lower thresholds for Dmin; no differences for Dmax. (iv) Vernier: females have lower thresholds. (v) Color appearance: hue and saturation functions of males shifted uniformly to longer wavelengths
Conclusions: :
There are sex effects on the neural mechanisms of many visual functions, which presumably involve multiple cortical areas.
Keywords: contrast sensitivity • color appearance/constancy • depth