title: Colour-opponent mechanisms are not affected by age-related chromatic sensitivity changes.
abstract: The purpose of this study was to assess whether age-related chromatic sensitivity changes are associated with corresponding changes in hue perception in a large sample of colour-normal observers over a wide age range (n = 185; age range: 18-75 years). In these observers we determined both the sensitivity along the protan, deutan and tritan line; and settings for the four unique hues, from which the characteristics of the higher-order colour mechanisms can be derived. We found a significant decrease in chromatic sensitivity due to ageing, in particular along the tritan line. From the unique hue settings we derived the cone weightings associated with the colour mechanisms that are at equilibrium for the four unique hues. We found that the relative cone weightings (w(L) /w(M) and w(L) /w(S)) associated with the unique hues were independent of age. Our results are consistent with previous findings that the unique hues are rather constant with age while chromatic sensitivity declines. They also provide evidence in favour of the hypothesis that higher-order colour mechanisms are equipped with flexible cone weightings, as opposed to fixed weights. The mechanism underlying this compensation is still poorly understood.
authors.affiliation: School of Psychology, University of Liverpool, Bedford Street South, Liverpool, UK. s.m.wuerger@liverpool.ac.uk
authors.forename: Sophie
authors.initials: S
authors.lastname: Wuerger
authors.forename: Kaida
authors.initials: K
authors.lastname: Xiao
authors.forename: Chenyang
authors.initials: C
authors.lastname: Fu
authors.forename: Dimosthenis
authors.initials: D
authors.lastname: Karatzas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000523:psychology*; D003118:Color Perception / Q000502:physiology*; D003119:Color Perception Tests / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D012684:Sensory Thresholds / Q000502:physiology; D055815:Young Adult