Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Motion perception at scotopic light levels

Not Accessible

Your library or personal account may give you access

Abstract

Although the spatial and temporal properties of rod-mediated vision have been extensively characterized, little is known about scotopic motion perception. To provide such information, we determined thresholds for the detection and identification of the direction of motion of sinusoidal grating patches moving at speeds from 1 to 32 deg/s, under scotopic light levels, in four different types of observers: three normals, a rod monochromat (who lacks all cone vision), an S-cone monochromat (who lacks M- and L-cone vision), and four deuteranopes (who lack M-cone vision). The deuteranopes, whose motion perception does not differ from that of normals, allowed us to measure rod and L-cone thresholds under silent substitution conditions and to compare directly the perceived velocity for moving stimuli detected by either rod or cone vision at the same light level. We find, for rod as for cone vision, that the direction of motion can be reliably identified very near to detection threshold. In contrast, the perceived velocity of rod-mediated stimuli is reduced by approximately 20% relative to cone-mediated stimuli at temporal frequencies below 4 Hz and at all intensity levels investigated (0.92 to -1.12 log cd m-2). Most likely, the difference in velocity perception is distal in origin because rod and cone signals converge in the retina and further processing of their combined signals in the visual cortex is presumably identical. To account for the difference, we propose a model of velocity, in which the greater temporal averaging of rod signals in the retina leads to an attenuation of the motion signal in the detectors tuned to high velocities.

© 2000 Optical Society of America

Full Article  |  PDF Article
More Like This
Photoreceptor-specific light adaptation of critical flicker frequency in trichromat and dichromat observers

Cord Huchzermeyer, Cristiane M. G. Martins, Balázs Nagy, Mirella T. S. Barboni, Dora F. Ventura, Marcelo F. Costa, and Jan Kremers
J. Opt. Soc. Am. A 35(4) B106-B113 (2018)

L/M cone ratios in human trichromats assessed by psychophysics, electroretinography, and retinal densitometry

Jan Kremers, Hendrik P. N. Scholl, Holger Knau, Tos T. J. M. Berendschot, Tomoaki Usui, and Lindsay T. Sharpe
J. Opt. Soc. Am. A 17(3) 517-526 (2000)

Evidence for the contribution of S cones to the detection of flicker brightness and red–green

Harald J. Teufel and Christian Wehrhahn
J. Opt. Soc. Am. A 17(6) 994-1006 (2000)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (6)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved