Exploring the Predictive Role of Lexical Stress Discrimination in the Phonological and Grammatical Skills of Teenagers With Down Syndrome.

Background: Temporal-sampling theory suggests that lexical stress discrimination plays an important role in language disorders. This study explored whether this is also the case in Down syndrome (DS) and, particularly, whether lexical stress discrimination could contribute to accounting for the phonological and grammatical skills of teenagers with this syndrome.

Method: Lexical stress discrimination, along with a range of phonological and grammatical skills, was assessed in a group of 27 teenagers with DS. The differential predictive role of lexical stress discrimination in phonology and grammar was studied, taking into account the potential effect of other relevant variables, namely, hearing thresholds, verbal short-term memory, chronological age and non-verbal cognition.

Results: Regression models revealed that, for the phonological measurements, only verbal short-term memory emerged as a significant predictor. For grammatical integration and sentence repetition, both verbal short-term memory and lexical stress discrimination played a predictive role. For grammar comprehension, lexical stress discrimination was the only significant predictor.

Conclusions: The results regarding grammar are consistent with a temporal-sampling framework. Given the observed predictive role of lexical stress discrimination in the grammatical skills of teenagers with DS, this prosodic skill could potentially be examined and incorporated as a prospective target in intervention programmes.