Eyetracking of social preference choices reveals normal but faster processing in autism.
People with Autism Spectrum Disorder (ASD) have been reported to show atypical attention and evaluative processing, in particular for social stimuli such as faces. The usual measure in these studies is an explicit, subjective judgment, which is the culmination of complex-temporally extended processes that are not typically dissected in detail. Here we addressed a neglected aspect of social decision-making in order to gain further insight into the underlying mechanisms: the temporal evolution of the choice. We investigated this issue by quantifying the alternating patterns of gaze onto faces, as well as nonsocial stimuli, while subjects had to decide which of the two stimuli they preferred. Surprisingly, the temporal profile of fixations relating to choice (the so-called "gaze cascade") was entirely normal in ASD, as were the eventual preference choices. Despite these similarities, we found two key abnormalities: people with ASD made choices more rapidly than did control subjects across the board, and their reaction times for social preference judgments were insensitive to choice difficulty. We suggest that ASD features an altered decision-making process when basing choice on social preferences. One hypothesis motivated by these data is that a choice criterion is reached in ASD regardless of the discriminability of the options.
Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA. Electronic address: alma.gharib@gmail.com.
Alma
A
Gharib
Department of Clinical Psychology, Central Institute of Mental Health, University of Heidelberg/Medical Faculty Mannheim, Germany.
Daniela
D
Mier
Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Division of Humanities & Social Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
Ralph
R
Adolphs
Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
Shinsuke
S
Shimojo
D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D001321:Autistic Disorder / Q000503:physiopathology*; D002755:Choice Behavior / Q000502:physiology*; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D007600:Judgment; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012938:Social Perception; D055815:Young Adult
Autism; Decision-making; Eye-tracking; Gaze bias; Reaction time; Social