Abstract: Working memory capacity is of central importance for many complex cognitive tasks such as language comprehension. Previous research has focused on how working memory capacity affects syntactic, semantic, and pragmatic processing. It is not clear whether working memory capacity also affects prosody. At the prosodic level, the correspondences between accentuation and information structure have been proven to exert an influence on discourse comprehension. This study explored the influence of working memory capacity on accentuation effects in discourse comprehension from an individual difference approach.
High (n=27) and low (n=23) working memory span participants were selected by Reading Span Test from 106 college students. Sentence-by-Sentence Auditory Moving Window Paradigm was employed to measure the effects of accentuation on discourse comprehension, with 24 discourses (each containing 5 sentences) as materials. The on-line processing time of discourse comprehension, measured by difference time, was compared among 3 conditions: consistent accentuation condition, inconsistent accentuation condition and controlled condition.
Low working memory span participants showed speeded on-ling processing in the consistent condition, and slowed processing in the inconsistent condition. High span participants, on the other hand, showed neither effect. High and low span participants did not differ significantly in either the consistent or neutral accentuation conditions. In the inconsistent accentuation condition, however, low span participants spent significantly more time on the on-line processing of spoken discourse than high span participants.
These results suggest that:
(1) Accentuation effects in discourse comprehension are influenced by working memory capacity, and the influence can be explained by the controlled attention view of working memory.　
(2) Practical implications of this study would be to call attention to the appropriate employment of prosody such as accentuation, especially during the verbal communication with people who have lower working memory capacity.

Key words: working memory span, individual differences, accentuation, information structure, discourse processing