Abstract:

Reading comprehension is one of the most complex behaviors that we engage in on a regular basis. Decoding and language comprehension are two important components of reading comprehension. While up to now, little research has been devoted to directly explore the effects of phonological memory and central executive function on diverse reading comprehension components (decoding and language comprehension). In addition, the primary school stage is a critical period of development of children's reading ability and cognitive ability. However, few research has focused on the developmental changes in the relationship of phonological memory, central executive function and reading comprehension among children in different grades. Therefore, the purpose of this study is to examine the contribution of phonological memory and central executive function on decoding and language comprehension of children in different grade levels.

Two hundred and fifty-six children completed Chinese Characters Reading, Chinese Word Reading, and Pseudo-Word Reading to investigate decoding ability, as well as a Listening Comprehension Test to exam language comprehension. Additionally, we used Digit Span and Non-word Span to measure children's phonological memory, and GO/NOGO task, Stroop task, Digit updating task and Digit shifting task to investigate children's central executive function. Correlation analysis and structural equation models (SEM) were used to investigate the effects of phonological memory and central executive function on decoding, language comprehension of children in different grades.

Results indicated that, the effect of phonological memory and updating on decoding were significant. Also, the effect of updating and shifting on language comprehension were significant. On further analysis, we divided the four grades into two levels based on the reading stage theory, that third grade and fourth grade as one level, fifth grade and sixth grade as another level. In the third grade and fourth grade level, phonological memory and updating accuracy contributed to decoding. Moreover, updating accuracy and shifting cost predicted language comprehension. In the fifth grade and sixth grade level, only the effect of updating on decoding was significant.The results indicated that, the prediction of phonological memory on decoding disappeared as children progress through school. More importantly, we found that updating had a relatively stable contribution to decoding across grade levels.

It revealed that different functions of working memory played different roles in reading, which seem that not all cognitive abilities are equally important in the reading process. Furthermore, phonological memory and central executive function produced different predictive effects in decoding and language comprehension as the grades grew.

Key words: phonological memory, central executive function, primary school children, decoding, language comprehension