Age-related changes in executive function and Chinese reading comprehension among primary school students in Hong Kong

Abstract

Reading and understanding text is a complex process employing an array of cognitive skills. Recently, a growing body of research indicates executive function is associated with reading comprehension performance (Follmer, 2017). Executive function is an umbrella term used for a diversity of hypothesised cognitive processes such as updating information (also known as “working memory”), suppressing prepotent responses (i.e. “inhibition control”) and shifting between mental sets (i.e. “cognitive flexibility”). However, at present, there are still a few ambiguities on the relation between executive function and reading comprehension. First, the executive function construct is often being challenged on the conceptualization and operationalization (Baggetta et al., 2016). Second, studies of the relationship between executive function and reading comprehension seldom include all three primary components (i.e. working memory, inhibition control, and cognitive flexibility) in one study. Third, it is unclear of why executive function contributes to reading comprehension. Lastly, the age-related difference in the relation between executive function and reading comprehension has seldom been discussed or explored.

To delineate the relation between executive function and Chinese reading comprehension during middle childhood, the present study recruited 409 Chinese-speaking primary school students, aged 7-12, from eight Hong Kong primary schools. A battery of measures tapping onto executive function components, reading skills (i.e. syntactic awareness, text-connecting inferencing, and extratextual inferencing), and reading comprehension was examined in the present study.

The finding revealed a differentiation on the structural organization of executive function components transiting from early-middle childhood into late-middle childhood. Executive function components converged into a one-factor construct, “unitary executive function” during early-middle childhood; with age, the components diverged into a two factor construct, including the components of “working memory” and “inhibition/ cognitive flexibility”, during late-middle childhood.

The construct of executive function was found significantly predicting to Chinese reading comprehension for both groups of students as hypothesised. Using a structural equation modelling approach, the present study further illustrated the cognitive mechanism underneath such relationship in each group. It showed that students’ awareness of the sentential grammatical structure (i.e. syntactic awareness) and integration of sentences (i.e. text-connecting inferencing) were partially mediating the relation between executive function and reading comprehension. More importantly, it implied that executive function does not only support reading comprehension, but it is also required to operate reading skills during the process in accomplishing the reading task.

On top of that, age-related difference in the model of reading comprehension was illustrated between early-middle childhood and late-middle childhood groups. The results showed that the “unitary executive function” had a direct effect on Chinese reading comprehension for the early-middle childhood group, and the “inhibition/ cognitive flexibility” had a direct effect on Chinese reading comprehension for the late-middle childhood group. After all, the age-related difference has an important implication on the individual difference of reading comprehension. It suggested that executive function development is closely related to reading in the transition of early-middle childhood into late-middle childhood. Meanwhile, “inhibition/ cognitive flexibility” exerts a more and more important role in later reading development.