title: Oblique orientation discrimination thresholds are superior in those with a high level of autistic traits.
abstract: Enhanced low-level perception, although present in individuals with autism, is not seen in individuals with high, but non-clinical, levels of autistic traits (Brock et al.in Percept Lond 40(6):739. doi: 10.1068/p6953 , 2011). This is surprising, as many of the higher-level visual differences found in autism have been shown to correlate with autistic traits in non-clinical samples. Here we measure vertical-oblique and, more difficult, oblique-oblique orientation discrimination thresholds in a non-clinical sample. As predicted, oblique-oblique thresholds provided a more sensitive test of orientation discrimination, and were negatively related to autistic traits (N = 94, r = -.356, p < .0001). We conclude that individual differences in orientation discrimination and autistic traits are related, and suggest that both of these factors could be mediated by increased levels of the inhibitory neurotransmitter GABA.
authors.affiliation: Department of Psychology, University of Sheffield, Western Bank, Sheffield, S10 2TP, UK.
authors.forename: Abigail
authors.initials: A
authors.lastname: Dickinson
authors.forename: Myles
authors.initials: M
authors.lastname: Jones
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Milne
mesh_terms: D000293:Adolescent; D000328:Adult; D001321:Autistic Disorder / Q000503:physiopathology*; D004192:Discrimination, Psychological / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009949:Orientation / Q000502:physiology*; D010775:Photic Stimulation; D011795:Surveys and Questionnaires; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult