title: Anomalous loss in blue-green wavelength discrimination with very brief monochromatic stimuli presented to the normal human eye.
abstract: The wavelength-discrimination curve of the normal human eye shows minima in discrimination thresholds at about 490 and 580 nm for viewing times of 1 s or longer. A reduction in viewing time was found to yield non-uniform increases in discrimination thresholds in the blue-green region of the spectrum, and these findings were quantified in objective, two-interval, forced-choice discrimination measurements. Monochromatic stimuli were presented foveally in a circular, horizontally oriented, bipartite field of 100 Td and angular subtense 2 degrees. When viewing time was decreased to 3 ms there was a sharp increase in discrimination threshold over 490-520 nm, maximizing near 500 nm. In this region, the fields appeared markedly desaturated. The loss in discrimination was distinct from that exhibited by tritanopes, and a control experiment showed that the effect was not attributable to the reduced energy of the short flash.
authors.affiliation: Department of Communication and Neuroscience, University of Keele, Staffordshire, UK.
authors.forename: M O
authors.initials: MO
authors.lastname: Scase
authors.forename: D H
authors.initials: DH
authors.lastname: Foster
mesh_terms: D000328:Adult; D003118:Color Perception / Q000502:physiology*; D006801:Humans; D008027:Light; D008297:Male; D012684:Sensory Thresholds / Q000502:physiology; D013997:Time Factors