Enhanced Rationality & Behavioral Invariance in Autism

Neil A. Harrison, MBBS, MRCP, MRCP1, Benedetto De Martino, PhD2, Steven Knafo, MSc1, Geoff Bird, PhD1, and Raymond J. Dolan, MD, FMedSci2. (1) Institute of Cognitive Neuroscience, University College London, Alexandra House, 17 Queen Square, London, WC1N 3AR, United Kingdom, (2) Wellcome Trust Centre for Neuroimaging, University College London, 12 Queen Square, London, WC1N 3BG, United Kingdom

Background:Decisions in healthy humans are intimately interwoven with their context or ‘frame’ in a manner that can lead to logically inconsistent choices. A recent study suggests that ‘framing effects’ result from amygdala activity which serves as a simplifying affect heuristic rapidly guiding context specific behavior. Autistic individuals show a marked inability to integrate incoming perceptual information (weak central coherence) however their susceptibility to framing effects are unknown.

Objectives: To determine whether choice behavior in Autism is less susceptibility to frame effects leading to decision invariance or ‘hyper-rationality’ that may underlie Autism associated behavioral rigidity and social impairment.

Methods: Fourteen Autistic and 15 control subjects were compared on susceptibility to frame using a financial task involving a choice between risky and sure options in ‘gain’ and ‘loss’ frames. Subjects were age, sex and I.Q. matched. Skin conductance response (SCR) was recorded throughout. ‘Need for Cognition’ (NFC) and ‘Cognitive Reflection Tests’ (CRT) questionnaires and Autism Diagnostic Observation Schedule (ADOS) were also completed.

Results: Autistic subjects showed a striking reduced susceptibility to frame compared to controls (p<0.01). Further SCR responses in controls but not Autism differentiated ‘gain’ from ‘loss’ frames (Interaction p=0.03). Decision invariance was independent of risk behavior and did not correlate with NFC, CRT or ADOS sub-scores.

Conclusions: Inability to incorporate contextual information including subtle social cues may underlie behavioral invariance and impaired social interaction that characterizes Autistic disorders. Failure to mount an SCR suggests this may result from impaired generation or integration of amygdala based signals.