Verb‐mediated anticipatory eye movements in people with Down syndrome

Abstract

Background: 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. Aims: To investigate whether children and young people with DS employ verb information to predict and anticipate upcoming linguistic information. Methods & Procedures: 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').Outcomes & Results: 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. Conclusions & Implications: 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. What this paper addsWhat is already known on the subject Children and adults, under typical development, anticipate information based on verbal cues. After hearing a semantically informative verb, children prefer to look at a target that matches such a verb than to a distractor. People with DS exhibit good comprehension skills at the vocabulary level, particularly, in some grammatical categories as nouns or verbs. Can they use verbal comprehension to anticipated linguistic information? What this paper adds to existing knowledgeThis study demonstrates that children and teenagers with DS anticipate upcoming information upon hearing a semantically informative verb. Also, that prediction skills are associated with mental age. It concludes that people with DS have sophisticated comprehension skills that call for new models to study their processing of language.Verb-mediated anticipatory eye movements in people with Down syndrome 757 What are the potential or actual clinical implications of this work?The results could contribute to the development of improvements in language interventions. Prediction skills facilitate real-time interactions with other people and the environment. Training in language prediction skills could also assist with other cognitive difficulties of people with DS, such as the production of number and tense morphemes.

Word prediction using closely and moderately related verbs in Down syndrome

“…We also found that mental age influences prediction in people with DS in an unexpected direction: participants with DS with greater mental age looked less at the target in the MV condition. This result is contrary to that of Arias-Trejo et al (2019) , who found a positive correlation between mental age and the predictive ability of people with DS. Differences in the mental age evaluation might explain this discrepancy.…”

“…Differences in the mental age evaluation might explain this discrepancy. Arias-Trejo et al (2019) computed mental age by evaluating verbal and non-verbal cognitive domains. In the present study, mental age was based on comprehension ability.…”

“… Arias-Trejo et al (2019) demonstrate that children with DS can use the verb information to make predictions. Verbs provide information about the action and important semantic and grammatical information about the agent and patient of the action.…”

“…There are also several studies on prediction during language comprehension in younger populations, such as infants and school children with typical development (TD), that demonstrate prediction skills as early as 24 months of age ( Borovsky et al, 2012 ; Mani and Huettig, 2012 ; Lukyanenko and Fisher, 2016 ; Mani et al, 2016 ; Gambi et al, 2018 ). However, little is known about people with genetic syndromes that lead to different developmental trajectories ( Arias-Trejo et al, 2019 ).…”

“…If people with DS have production problems, they should therefore also have problems with prediction; however, there is evidence for some prediction skills in this population. In a preferential-looking task using an eye-tracker, Arias-Trejo et al (2019) reported that children with DS (mental age: 5.48 years), as well as their TD peers matched by mental age, used the semantic information contained in a verb (e.g., eat ) to anticipate an edible target (e.g., cake ) in preference to a non-edible distractor. Thus, the question is, if people with DS have problems with production, how do they make predictions about upcoming linguistic information?…”