Spatial Working Memory and Patterns of Academic Achievement In 9-Year-Old Children with ASD

Background: Academic achievement in children with ASD is not yet well understood.  Recent evidence suggests that children with ASD, 90% in one study (Estes et al., 2010), are highly likely to show a discrepancy between IQ and academic achievement.  In that study, children with significant discrepancies demonstrated both higher-than-expected and lower-than-expected achievement. Examination of neurocognitive factors may shed light on the heterogeneous academic achievement outcomes observed in this population. For example, poor SWM skills have been associated with poorer arithmetic skills in typically developing children and adults and with lower early numeracy skills in typically developing children. However, research is needed to understand the relationship between SWM and academic achievement in ASD.  

Objectives: This study will examine the relationship between SWM and academic outcomes in a sample of school-aged children with ASD. More specifically, this study will (1) examine the relationship between SWM at age 6 and math, spelling, and reading skills at age 9. 

Methods: Thirty participants were recruited from a larger longitudinal study on the neurobiology and developmental course of ASD at the University of Washington. All thirty children had a clinical diagnosis of ASD based on the Autism Diagnostic Interview-Revised (ADI-R), Autism Diagnostic Observation Schedule (ADOS), and DSM-IV. Participants demonstrated a nonverbal IQ over 70 at age 9 and were able to complete a standardized measure of academic achievement. Data reported for the current study was obtained when participating children were aged 6 and 9 years. Intellectual ability was measured at age 6 and 9 and academic achievement was assessed at age 9 using the Differential Ability Scales. The DAS Achievement Test consists of three academic subtests: Basic Number Skills, Spelling, and Word Reading. SWM was measured at age 6 using the Spatial Reversal (Kaufman et al., 1990) and A not B with invisible displacement (Diamond et al., 1997). 

Results: This study will test the hypothesis that better performance on SWM tasks (spatial reversal and A-not-B with invisible displacement) at age 6 will be associated with higher scores on the Basic Number Skills subtest at age 9 but not higher scores on the Word Reading subtest. We will also test an exploratory hypothesis that performance on SWM tasks at age 6 will be related to improved Spelling scores at age 9. 

Conclusions: Studying the relationship between neurocognitive functioning and academic outcomes in children with ASD is important because it may help to identify specific skills and intervention strategies to support improved academic achievement in children with ASD.  Furthermore, it may assist with identifying children at-risk for later academic difficulties.  Finding neurocognitive protective factors, such as strong spatial work memory, could provide clues about the positive outcomes observed in many children with ASD.