Distinguishing reality from fantasy in adults with autism spectrum disorder: Evidence from eye movements and reading

Understanding fictional events requires one to distinguish reality from fantasy, and thus engages high-level processes including executive functions and imagination, both of which are impaired in autism spectrum disorder (ASD). We examined how adults with and without ASD make sense of reality-violating fantasy narratives by testing real-time understanding of counterfactuals. Participants were eye-tracked as they read narratives that depicted novel counterfactual scenarios that violate reality (e.g. “If margarine contained detergent, Mum could use margarine in her washing/baking”, Experiment 1), or counterfactual versions of known fictional worlds (e.g. “If Harry Potter had lost all his magic powers, he would use his broom to sweep/fly”, Experiment 2). Results revealed anomaly detection effects in the early moments of processing (immediately in Experiment 1, and from the post-critical region in Experiment 2), which were not modulated by group. We discuss how these patterns reveal a dissociation between ToM impairments and counterfactual processing abilities, and more generally how constraints from real-world and fantasy context compete to influence language comprehension.