Rod-cone interactions and the temporal impulse response of the cone pathway.
Dark-adapted rods suppress cone-mediated flicker detection. This study evaluates the effect that rod activity has on cone temporal processing by investigating whether rod mediated suppression changes the cone pathway impulse response function, regardless of the form of the temporal signal. Stimuli were generated with a 2-channel photostimulator that has four primaries for the central field and four primaries for the surround. Cone pathway temporal impulse response functions were derived from temporal contrast sensitivity data with periodic stimuli, and from two-pulse discrimination data in which pairs of briefly pulsed stimuli were presented successively at a series of stimulus onset asynchronies. Dark-adapted rods altered the amplitude and timing of cone pathway temporal impulse response functions, irrespective of whether they were derived from measurements with temporally periodic stimuli or in a brief presentation temporal resolution task with pulsed stimuli. Rod-cone interactions are a fundamental operation in visual temporal processing under mesopic light levels, acting to decrease the temporal bandwidth of the visual system.
Zele
Andrew J
AJ
School of Optometry and The Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Brisbane, Qld 4059, Australia. andrew.zele@qut.edu.au
Cao
Dingcai
D
Pokorny
Joel
J
D015350:Contrast Sensitivity / Q000502:physiology; D003623:Dark Adaptation / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D055258:Rod-Cone Interaction / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology