Investigating the Role of Verbal and Non-Verbal Working Memory Measures in Complex Sentence Comprehension by School-Aged Greek Speaking Children.

OBJECTIVES: The present study examines the role of Working Memory (WM), as a cognitive system of limited storage-processing resources, in complex sentence comprehension by typically developing children in both the verbal and non-verbal domain. In particular, the study compares non-verbal and verbal measures of WM in regard to their contribution to complex sentence comprehension. METHODS: Participants were 169 children aged 8 to 12 years, native speakers of Greek. A self-paced reading task was used to assess the comprehension of syntactically complex sentences. The sentences tested were object-relatives. Non-verbal short-term memory (nvSTM) and non-verbal working memory (nvWM) was measured by corsi blocks forward and corsi blocks backward, respectively. Forward digit span was used for the measurement of verbal short-term memory (vSTM) and backward digit span for the assessment of verbal working memory (vWM). RESULTS: Results showed that the only significant predictor of children's comprehension was backward digit span. CONCLUSIONS: Findings suggest an important role of vWM in the comprehension of syntactically complex structures, lending support to the view that language comprehension is underpinned by a domain-specific cognitive system specialized to verbal processing.