title: Mesopic rod and S-cone interactions revealed by modulation thresholds.
abstract: We analyzed mesopic rod and S-cone interactions in terms of their contributions to the blue-yellow opponent pathway. Stimuli were generated using a four-primary colorimeter. Mixed rod and S-cone modulation thresholds (constant L-, M-cone excitation) were measured as a function of their phase difference. Modulation amplitude was equated using threshold units and contrast ratios. This study identified three interaction types: (1) a linear and antagonistic rod:S-cone interaction, (2) probability summation, and (3) a previously unidentified mutual nonlinear reinforcement. Linear rod:S-cone interactions occur within the blue-yellow opponent pathway. Probability summation involves signaling by different postreceptoral pathways. The origin of the nonlinear reinforcement is possibly at the photoreceptors.
authors.affiliation: Visual Science Laboratory, School of Optometry and Vision Science & Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia. andrew.zele@qut.edu.au
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Zele
authors.forename: Jan
authors.initials: J
authors.lastname: Kremers
authors.forename: Beatrix
authors.initials: B
authors.lastname: Feigl
mesh_terms: D003116:Color; D003124:Colorimetry; D006801:Humans; D010775:Photic Stimulation; D017949:Retinal Cone Photoreceptor Cells / Q000166:cytology*; D017948:Retinal Rod Photoreceptor Cells / Q000166:cytology*; D055258:Rod-Cone Interaction