Reading and Oral Language Comprehension in Students with ASD

Background:

A small, but expanding, body of research has indicated that reading comprehension can be challenging for students with ASD. The Simple Model of Reading (Perfetti, Landi & Oakhill, 2005) posits that reading ability is comprised of two processes: (1) word reading ability and (2) oral language processing that creates meaning from the words.  This is important because one of the cardinal diagnostic criteria in the DSM-IV for autism is delayed or abnormal functioning in communication and language (APA, 2000).  Therefore, it may be that reading comprehension deficits are part of the expression of the social communication symptom domain of the phenotype of ASD.

Objectives:  

This study was designed to investigate the role of oral language comprehension in explaining impairments in reading comprehension in a sample of children with high functioning autism (HFA; FSIQ > 80). 

Methods:  

The study included 29 children with HFA and 36 typically developing control children, who were matched for age (range 8 to 16 years old) and IQ. Diagnosis was confirmed via multiple methods, including the ASSQ (1999), SCQ (1999) and SRS (2003) parent report questionnaires.  IQ was measured with the Wechsler Abbreviated Scales of Intelligence (1999), while reading comprehension and oral language comprehension were assessed with the Wechsler Individualized Achievement Test-III (2009). 

Results:  

Regression analyses revealed significant effects for Diagnostic Group on reading comprehension (RC), R = .24, p < .05, and oral language comprehension (OLC), R = .31, p < .01. Follow-up analyses indicated diagnostic group differences were more apparent on these variables for older subgroups of students (12 to 16 years) than for younger subgroups of students (8 to 11 years): for RC, p < .065 and OLC, p < .02.  A multiple regression analysis of RC indicated an effect for Diagnostic Group, R²= .05, F (1, 62) = 3.20, p < .02, and effect for OLC, change in R² = .23, F (1, 62) = 19.1, p < .001, and the DX by OLC diagnostic term, change in R²= .07, F (1,62) = 6.21, p< .02.   The interaction reflected the observation that the correlation between RC and OLC was .73, p < .001 in the HFA sample but .30, p < .35 in the TD sample. 

Conclusions:  

This study provides evidence that students with HFA display impairments both in reading comprehension and oral language comprehension. These impairments were more pronounced in older than younger children. Moreover, a primary observation was that OLC and RC displayed a significantly stronger association in the HFA sample than the TD sample. This supports prior research findings that oral language abilities in children with ASD significantly relate to their reading ability (Jones et al., 2009; Norbury & Nation, 2011; Randi, Newman & Grigorenko, 2010; Ricketts, 2011).  Moreover, they raise the possibility that reading comprehension deficits are part of the language communication impairments that are central to the nature of ASD.