Abstract

Contrast detection thresholds for moving sine wave gratings were obtained at the fovea and at eccentricities of 6°, 21°, and 50° on the nasal horizontal meridian. The targets subtended from 30 × 30 minutes of arc up to 16° × 16°. Mean retinal illuminance was varied between 10 and 0.01 trolands. The transition from the de Vries–Rose to the Weber region occurs in the far peripheral visual field at a 2–3 decades lower illuminance level than at the fovea. The spatio-temporal contrast detection thresholds become comparable over the whole visual field if the mean distance between retinal ganglion cells is taken as a yardstick, and field width, spatial frequency, and quantum density are scaled accordingly. This means that at scotopic illuminance levels coarse or medium gratings are preferentially detected at other than foveal locations. (The fine gratings cannot be resolved at all at such levels.) It is argued that both electrophysiological and psychophysical evidence indicates that Weber behavior starts whenever some small fixed number of quantum absorptions occur within an area of 1 mean interganglion cell distance across. Or, equivalently, if a fixed small number of “neural quanta” enters a 100 × 100 μm² area of the visual cortex.

© 1978 Optical Society of America

Perimetry of contrast detection thresholds of moving spatial sine wave patterns. III. The target extent as a sensitivity controlling parameter

Jan J. Koenderink, Maarten A. Bouman, Albert E. Bueno de Mesquita, and Sybe Slappendel
J. Opt. Soc. Am. 68(6) 854-860 (1978)

Perimetry of contrast detection thresholds of moving spatial sine wave patterns. II. The far peripheral visual field (eccentricity 0°–50°)

Jan J. Koenderink, Maarten A. Bouman, Albert E. Bueno de Mesquita, and Sybe Slappendel
J. Opt. Soc. Am. 68(6) 850-854 (1978)

Perimetry of contrast detection thresholds of moving spatial sine wave patterns. I. The near peripheral visual field (eccentricity 0°–8°)

Jan J. Koenderink, Maarten A. Bouman, Albert E. Bueno de Mesquita, and Sybe Slappendel
J. Opt. Soc. Am. 68(6) 845-849 (1978)

Spatial Resolution by the Human Visual System. The Effect of Mean Retinal Illuminance*

A. S. Patel
J. Opt. Soc. Am. 56(5) 689-694 (1966)

Stereoscopic acuity for moving retinal images*

Gerald Westheimer and Suzanne P. McKee
J. Opt. Soc. Am. 68(4) 450-455 (1978)