Eye-Tracking Measures of Reading Comprehension and Autistic Traits

Background: Reading comprehension difficulties are widely reported in autism. Frith and Snowling (1983) reported that children with autism had difficulty choosing the contextually appropriate meaning and pronunciation of homographs – ambiguous written words – when reading sentences aloud. This finding has been replicated on numerous occasions and is cited as key evidence for the “weak central coherence” account of autism. However, the precise cognitive mechanisms involved have not been ascertained.

Objectives: We developed eye-tracking measures of contextual facilitation and contextual integration during reading comprehension. As a first step, we investigated individual differences in effect size as a function of subclinical autistic traits in a neurotypical population.

Methods: Eye-movements of 71 undergraduate students were measured as they silently read sentences on a computer screen. In addition, participants completed the Autism Quotient, a questionnaire measure of autism-like traits. Experiment 1 involved a predictability manipulation in which a target word was either highly predictable or entirely unpredictable based on the preceding context. Contextual facilitation was indexed by a reduction in fixation time on target words as a function of predictability. Experiment 2 involved an ambiguity manipulation whereby half of the sentences contained a homograph that was disambiguated by a subsequent word, and half the sentences replaced the homograph with an unambiguous synonym or semantic associate. An increase in go-past time for words that disambiguated an earlier homograph was taken as a measure of contextual integration.

Results: The predictability and ambiguity manipulations were both highly significant, but only the ambiguity effect interacted with AQ scores. Individuals with high levels of autistic traits were relatively slower to saccade past a disambiguating word, indicating greater difficulty integrating the disambiguating word with the preceding homograph.

Conclusions: The current study is the first to our knowledge to use eye-tracking to investigate the relationship between reading comprehension and autistic traits. Future studies will use the same materials to test adults on the autism spectrum and will help elucidate the cognitive mechanisms underpinning “weak central coherence”.