Verb-mediated anticipatory eye movements in people with Down syndrome.

Abstract

Children and adults with neurotypical development employ linguistic information to predict and anticipate information. Individuals with Down syndrome (DS) have weaknesses in language production and the domain of grammar but relative strengths in language comprehension and the domain of semantics. What is not clear is the extent to which they can use linguistic information, as it unfolds in real time, to anticipate upcoming information correctly. To investigate whether children and young people with DS employ verb information to predict and anticipate upcoming linguistic information. A preferential looking task was performed, using an eye-tracker, with children and teenagers with DS and a typically developing (TD) control group matched by sex and mental age (average = 5.48 years). In each of 10 trials, two images were presented, a target and a distractor, while participants heard a phrase that contained a semantically informative verb (e.g., 'eat') or an uninformative verb (e.g., 'see'). Both DS and TD control participants could anticipate the target upon hearing an informative verb, and prediction skills were positively correlated with mental age in those with DS. This work demonstrates for the first time that children and teenagers with DS can predict linguistic information based on semantic cues from verbs, and that sentence processing is driven by predictive relationships between verbs and arguments, as in children with typical development. Clinicians can take advantage of these prediction skills, using them in therapy to support weaker areas.