title: Colour vision in ADHD: part 1--testing the retinal dopaminergic hypothesis.
abstract: OBJECTIVE
  To test the retinal dopaminergic hypothesis, which posits deficient blue color perception in ADHD, resulting from hypofunctioning CNS and retinal dopamine, to which blue cones are exquisitely sensitive. Also, purported sex differences in red color perception were explored.
  
  
  METHODS
  30 young adults diagnosed with ADHD and 30 healthy young adults, matched on age and gender, performed a psychophysical task to measure blue and red color saturation and contrast discrimination ability. Visual function measures, such as the Visual Activities Questionnaire (VAQ) and Farnsworth-Munsell 100 hue test (FMT), were also administered.
  
  
  RESULTS
  Females with ADHD were less accurate in discriminating blue and red color saturation relative to controls but did not differ in contrast sensitivity. Female control participants were better at discriminating red saturation than males, but no sex difference was present within the ADHD group.
  
  
  CONCLUSIONS
  Poorer discrimination of red as well as blue color saturation in the female ADHD group may be partly attributable to a hypo-dopaminergic state in the retina, given that color perception (blue-yellow and red-green) is based on input from S-cones (short wavelength cone system) early in the visual pathway. The origin of female superiority in red perception may be rooted in sex-specific functional specialization in hunter-gather societies. The absence of this sexual dimorphism for red colour perception in ADHD females warrants further investigation.
authors.forename: Soyeon
authors.initials: S
authors.lastname: Kim
authors.forename: Mohamed
authors.initials: M
authors.lastname: Al-Haj
authors.forename: Samantha
authors.initials: S
authors.lastname: Chen
authors.forename: Stuart
authors.initials: S
authors.lastname: Fuller
authors.forename: Umesh
authors.initials: U
authors.lastname: Jain
authors.forename: Marisa
authors.initials: M
authors.lastname: Carrasco
authors.affiliation: Department of Applied Psychology & Human Development, OISE, University of Toronto, 252 Bloor Street West, Toronto, ON M5S 1 V6, Canada. rosemary.tannock@utoronto.ca.
authors.forename: Rosemary
authors.initials: R
authors.lastname: Tannock
mesh_terms: D000293:Adolescent; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000378:metabolism* / Q000503:physiopathology / Q000523:psychology*; D003116:Color; D003118:Color Perception; D055253:Color Vision; D004192:Discrimination, Psychological; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D012160:Retina / Q000378:metabolism* / Q000503:physiopathology; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D012727:Sex Characteristics; D055815:Young Adult
chemical_list: D004298:Dopamine