The purpose of this study was to investigate the characteristics of verbal working memory in
children with reading difficulties (poor readers) using three measures of working memory; nonword
repetition, sentence repetition, and reading span tests. Twenty seven poor readers in grade 2 or 4, and
30 typically developing children of same grades participated in the study. The poor readers performed
significantly worse than the typically developing peers in all three measures of verbal working memory.
Separate MANOVAs revealed that, in the 4th graders, the poor readers peformed significantly worse
than the typically developing peers in all three working memory measures. However, in the 2nd
graders, significant group differences were noted in the performances of nonword repeptition and
sentence repetition, but not in reading span test. In addition, the poor readers did not show significant
developmental changes between the grades in their performances of three working memory tests,
whereas typically developing 4th graders performed significantly better than the 2nd graders in nonword
repetition and reading span test. The correlation analyses among the scores of working memory
measures and reading test scores revealed that in the typically developing children, reading span had
significant relation with all three reading skills; word recognition, reading fluency, and reading
comprehension. However, in the poor readers, nonword repetition and sentence repetition were
significantly related with only reading comprehension. In conclusion, the poor readers exhibited
significant difficulties relative to their peers in all three verbal working memory measures regardless of
their grades. The poor readers’ developmental growth in working memory skills appeared to be
minimal. For the poor readers, the function of phonological loop and episodic buffer might have some
relation with reading comprehension. On the other hand, for the typically developing children, the
function of central executive appeared to be related to their reading skills in general.