Peripheral contrast sensitivity for sine-wave gratings and single periods.
نویسندگان
چکیده
The contrast sensitivity of the human eye has been measured as a function of eccentricity. The stimulus used was a sine-wave grating with a fixed height of 5’. in a surround of luminance that equals the average stimulus luminance. The measurements were carried out with stimulus width as the independent variable. The “local’. sensitivity for gratings was found to decrease monotonically with increasing eccentricity. It was further found that the sensitivity for wide gratings is mainly determined by that part which is only 1’ wide, situated as close to the fovea as possible. The results are discussed in view of the possible existence of “tuning”. i.e. of a maximal sensitivity outside the fovea. at an eccentricity determined by the spatial frequency.
منابع مشابه
Acute effect of alcohol intake on sine-wave Cartesian and polar contrast sensitivity functions
The aim of this study was to assess contrast sensitivity for angular frequency stimuli as well as for sine-wave gratings in adults under the effect of acute ingestion of alcohol. We measured the contrast sensitivity function (CSF) for gratings of 0.25, 1.25, 2.5, 4, 10, and 20 cycles per degree of visual angle (cpd) as well as for angular frequency stimuli of 1, 2, 4, 24, 48, and 96 cycles/360°...
متن کاملRadial frequency stimuli and sine-wave gratings seem to be processed by distinct contrast brain mechanisms.
An assumption commonly made in the study of visual perception is that the lower the contrast threshold for a given stimulus, the more sensitive and selective will be the mechanism that processes it. On the basis of this consideration, we investigated contrast thresholds for two classes of stimuli: sine-wave gratings and radial frequency stimuli (i.e., j0 targets or stimuli modulated by spherica...
متن کاملComparison of angular frequency contrast sensitivity in young and older adults.
The aim of the present study was to measure contrast sensitivity curves for angular frequencies in the range between 2 and 96 cycles/360 masculine in older human adult volunteers and to compare these measurements with the more usual contrast sensitivity functions for sine-wave gratings. All subjects were free of identifiable ocular disease and had normal acuity. We measured the contrast thresho...
متن کاملLETTERS TO THE EDITORS SPATIOTEMPORAL VARIATIONS IN THE SQUARE/SINE RATIO: EVIDENCE OF INDEPENDENT CHANNELS AT LOW SPATIAL FREQUENCIES lRecrirrd
Much psychophysical evidence has indicated that the human visual system contains a number of independent mechanisms. each selectively sensitive to a narrow band of spatial frequencies [see Braddick et al.. (1979) for a complete review]. The existence of such a “multiple channei” visual system was first suggested by Campbell and Robson (1968) who based their inference on the relative detectabili...
متن کاملDifferential effects of aging on spatial contrast sensitivity to linear and polar sine-wave gratings
Changes in visual function beyond high-contrast acuity are known to take place during normal aging. We determined whether sensitivity to linear sine-wave gratings and to an elementary stimulus preferentially processed in extrastriate areas could be distinctively affected by aging. We measured spatial contrast sensitivity twice for concentric polar (Bessel) and vertical linear gratings of 0.6, 2...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Vision research
دوره 20 3 شماره
صفحات -
تاریخ انتشار 1980