Online Metaphor Comprehension in Adults with Autism Spectrum Disorders: An Eye Tracking Study

The aim of this study was to investigate novel metaphor comprehension in adults with autism spectrum disorder (ASD). Previous literature is conflicting about whether individuals with ASD have impairment in this particular type of figurative language. Participants in the study completed a visual world paradigm eye-tracking task, which involved selecting an interpretation of an auditorily presented sentence (i.e. a picture-sentence matching task), where images corresponded to literal and metaphorical interpretations. Thus, the study also investigated online processing, via reaction times and eye movements. Forty adults participated in the study (18 with ASD and 22 typically-developing controls). Each participant completed the AQ questionnaire and had their vocabulary assessed. Results showed that participants with ASD comprehended metaphorical utterances with the same accuracy as controls. However, they had significantly slower reaction times, and specifically, were approximately 800 ms slower. Analysis of eye movements revealed that participants with ASD showed significantly longer fixation times on both the target and distractor image, the latter of which suggests difficulty overcoming the literal interpretation. Consistent with some prior studies, we showed that adults with ASD are not impaired in novel metaphor comprehension, but they were clearly less efficient. Verbal abilities did not significantly relate to performance. Finally, our online processing measure (eye tracking) provided us with insights into the nature of the ASD inefficiency (i.e. a literality bias).