# Phonological working memory and linguistic processing speed in inferential reading comprehension

## TL;DR

This study shows that both phonological working memory and language processing speed help children understand texts that require making inferences.

## Contribution

The study reveals that processing speed mediates the relationship between phonological working memory and inferential reading comprehension.

## Key findings

- Phonological working memory and processing speed both predict inferential reading comprehension in 5th graders.
- Language processing speed, measured by verbal fluency, mediates the effect of phonological working memory on reading comprehension.
- Processing speed contributes independently to reading comprehension, suggesting it is a distinct cognitive ability.

## Abstract

Phonological working memory has been known as an essential predictor of reading comprehension in children. However, less attention has been paid to processing speed and its interaction with working memory.

Research has indicated that higher processing speed of linguistic information contributes to greater availability of memory resources used to comprehend a read text.

We tested, using simple mediation models, whether phonological working memory can predict inferential reading comprehension when mediated by linguistic processing speed.

To do this, we analyzed information from a database on the assessment of phonological memory (digit span Backward and Forward task), language processing speed (Verbal Fluency and Rapid Automated Naming) and inferential reading comprehension of 66 typical 5th grade students.

Both phonological working memory and cognitive-linguistic information processing speed were able to predict the inferential reading comprehension of students in the 5th year of elementary school. The mediation analysis showed that rapid automatized naming and working memory (digit span Backward and Forward Task) together, but independently, were able to predict inferential reading comprehension.

When measured by semantic verbal fluency, linguistic processing speed mediated the prediction of phonological working memory (digits in Forward and Backward order) in inferential reading comprehension.

The online version contains supplementary material available at 10.1186/s41155-025-00356-z.

1. Language processing speed (measured by Semantic Verbal Fluency) mediated the effect of phonological working memory (Forward and Backward) in inferential reading comprehension.

2. Processing speed, assessed by semantic and phonological verbal fluency, correlated with the inferential comprehension of implicit information in the text.

3. Phonological working memory contributed to processing speed, assessed by the Verbal Fluency Task.

4. The direct and independent contribution of processing speed to reading comprehension shows that this can also be an independent ability.

The online version contains supplementary material available at 10.1186/s41155-025-00356-z.