Factors associated with individual differences in reading comprehension for typically-developing students and for a pilot sample of students diagnosed with autism spectrum disorder

This study investigated some of the underlying factors that may relate to and predict the reading comprehension of children in fourth through eighth grade (N=47). A subset of these children previously had been diagnosed with autism spectrum disorders (ASD; n=10); the remainder are classified as typically-developing (n=37). The participants were assessed on basic reading skills (i.e., word recognition, decoding, and reading fluency), receptive vocabulary, executive functioning (i.e., verbal working memory and planning/organization), and theory of mind. Correlational analyses were performed for each group to examine relationships between these measures and performance on the Comprehension subtest of the Stanford Diagnostic Reading Test, a standardized measure that includes different types of passages (i.e., narrative, expository, and functional) and asks different types of questions (e.g., literal, inferential). Next, the performance of the typically-developing participants was compared with children in the ASD group, and finally, predictors of overall reading comprehension and performance on the different passage types were explored. The results indicate that, for typically-developing participants, reading fluency and receptive vocabulary were significantly correlated with overall reading comprehension, performance on all passage types, and on initial understanding and interpretation questions. Likewise, for children in the ASD group, strong relationships were found between receptive vocabulary and performance on the comprehension measure (i.e., overall comprehension as well as performance on all text and question types). These results are consistent with previous research that has underscored the importance of reading fluency and vocabulary knowledge to reading comprehension in the general population (Fuchs, Fuchs, Hosp, & Jenkins, 2001; Catts, Adlof, and EllisWeismer, 2006; Storch & Whitehurst, 2002). Upon examining the relationships between the executive function measures and reading comprehension, verbal working memory was found to be a significant correlate in both groups, whereas planning/organization was significantly related to performance in the ASD group only. These findings are somewhat consistent with previous research documenting the relationship between reading comprehension and executive function in non-ASD populations, although in prior studies executive function has been measured in various ways (e.g., verbal/nonverbal working memory, planning, and organization, etc.; Best, Floyd, & McNamara, 2008; Cain, Oakhill, & Bryant, 2004; Eason, Goldberg, Young, Geist, & Cutting, 2012; Nation, Adams, Bowyer-Crane, & Snowling, 1999; Samuelstuen & Braten, 2005). Theory of mind did not contribute significantly to reading comprehension performance in the typically-developing group. However, as predicted, in the ASD group, strong associations were observed between theory of mind and narrative comprehension. Additionally, for this group, theory of mind significantly correlated with overall reading comprehension, performance on the other two types of passages, and scores on initial understanding and critical analysis/process strategies questions. These results were predicted in light of existing research that has found theory of mind impairments and other studies that have documented comprehension deficits in children diagnosed with ASD (Happe, 1994; Nation et al., 2006; O’Connor & Klein, 2004). An examination of group differences found that the typically-developing group tended to perform significantly better than the ASD group on a majority of the independent measures (i.e., reading fluency, executive functioning, and theory of mind), as well as on the reading comprehension measure. Specifically, these typicallydeveloping participants had better overall reading comprehension and scored higher on all types of texts and questions. These results are consistent with the aforementioned studies that have revealed deficits in these areas for children with ASD. Hierarchical multiple regression analyses performed on the data for the typicallydeveloping students had the result that reading fluency was a significant predictor of overall comprehension and performance on each of the passage types. Likewise, reading fluency explained the largest proportion of unique variance for these outcome measures. The findings corroborate previous research referring to reading fluency as an overall indicator of reading acquisition (e.g., Fuchs et al., 2001). In addition, receptive vocabulary contributed shared variance to the prediction of overall comprehension, and receptive vocabulary and word recognition each shared variance with reading fluency in the prediction of narrative comprehension. In combination, these results underscore the importance of basic reading skills and vocabulary knowledge for successful reading comprehension (Catts, Adlof, & Weismer, 2006; Perfetti, 1985; LaBerge & Samuels, 1974; Leach, Scarborough, & Rescorla, 2003). Taken together, the results of the present study provide educators with information about the ways in which particular cognitive abilities may contribute to children’s understanding of different types of text and their ability to answer varying types of questions. Awareness of the roles these factors play in reading comprehension may facilitate decision-making related to assessment and intervention in this area, both for typically-developing pupils and those with ASD.