Purchase this article with an account.
Natanael A Santos, Maria Lúcia B Simas, Renata Maria B. L. Nogueira; Comparing contrast sensitivities to angular frequency stimuli and sinewave gratings in aged. Journal of Vision 2003;3(9):655. doi: 10.1167/3.9.655.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We measured 12 contrast sensitivity functions for sinewave gratings (CSF) as well as 12 contrast sensitivity functions for angular frequency stimuli (aCSF) using a forced-choice paradigm.. Six volunteers (60–65 years-old) with normal vision assessed by ophthalmologist on the last 12 months participated on the experiments. We used spatial frequencies of 0.5, 1, 2, 3, 4, 6 and 9 cpg and angular frequencies of 2, 4, 8, 16, 24, 32, 48, 64 and 96 cycles/360o to measure each contrast sensitivity function. Stimuli were computer generated on a 21 inch monitor SONY-BVM-1910. All measures were made at a distance of 150 cm, binocularly, with mean luminance of 6.9 cd/m2. The stimuli were circular with a diameter of 7.25 degrees of visual angle. Maximum sensitivity occurred at 3–4 cpg for CSF and at 16–32 cycles/360° for aCSF. Sensitivity to angular frequencies (aFSC) was about 1.5 times higher than that for gratings (CSF). This effect was statistically significant at p<0.001. Results show that contrast sensitivities for angular frequencies are higher than for sinewave gratings
This PDF is available to Subscribers Only