title: Temporal Visual Mechanisms May Mediate Compensation for Macular Pigment.
abstract: Macular pigment (MP) is a pre-receptoral filter that is diet derived and deposited in relatively high optical density in the foveal region of the retina. Due to its yellow coloration, MP absorbs light of relatively short wavelengths, ranging from 400 nm to 520 nm. Despite the spectral and spatial nonuniformity imposed upon the sensory retina by MP, perception appears to be relatively uniform across the central visual field. MP therefore offers an opportunity to determine experimentally potential mechanisms responsible for mediating this uniformity. After assessing, in 14 subjects, MP's effects on the temporal sensitivity of both the short-wavelength- and middle-/long-wavelength-sensitive visual pathways, it appears that the visual system compensates for absorption of short-wavelength light by MP by slowing the sampling rate of short-wavelength cones and by increasing the processing speed of middle-/long-wavelength-sensitive cones. This mechanism could work via temporal summation or a temporal neural code, whereby slower response dynamics lead to amplification of relatively weak signals.
authors.affiliation: Nutritional Neuroscience Laboratory, Department of Psychology, University of Georgia, Athens, GA, USANeuroscience Division, Biomedical and Health Science Institute, University of Georgia, Athens, GA, USA ntstringham@gmail.com.
authors.forename: Nicole T
authors.initials: NT
authors.lastname: Stringham
authors.affiliation: Nutritional Neuroscience Laboratory, Department of Psychology, University of Georgia, Athens, GA, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Stringham
mesh_terms: D000328:Adult; D003118:Color Perception / Q000502:physiology; D055358:Cone Opsins / Q000502:physiology; D005260:Female; D005425:Flicker Fusion / Q000502:physiology; D006801:Humans; D065348:Macular Pigment / Q000502:physiology*; D008297:Male; D011930:Reaction Time / Q000502:physiology; D012160:Retina / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D014794:Visual Fields / Q000502:physiology; D014795:Visual Pathways / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
chemical_list: D055358:Cone Opsins; D065348:Macular Pigment
keywords: S-cones; color vision; macular pigment; neural plasticity; temporal processing; visual sensitivity