Assessment & Research

Working memory arrest in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder: results from a 2-year longitudinal study.

Andersen et al. (2015) · Autism : the international journal of research and practice 2015
★ The Verdict

Verbal working memory stalls in autistic kids while peers move ahead, so plan supports instead of hoping for growth.

✓ Read this if BCBAs serving autistic students in schools or clinics.
✗ Skip if Practitioners focused only on toddlers or adults with ASD.

01Research in Context

01

What this study did

The team tracked verbal working memory for two years in three groups of kids .

They compared the kids with high-functioning autism, 45 with ADHD, and 45 typically developing peers.

Every 12 months each child repeated a standard digit-span test while the researchers charted the scores.

02

What they found

Autistic kids’ scores stayed flat across the two years.

The ADHD and typical groups both gained about four extra digits by the end.

No autistic child showed a clear upward slope, even the brightest ones.

03

How this fits with other research

Pineau et al. (2019) also looked at working memory in ADHD kids, but used brain scans instead of repeated tests.

They found brain-activation changes even when behavior looked the same, showing ADHD brains compensate differently than autism’s plateau.

Scott et al. (2023) extended the autism tracking idea into university students, yet measured mental-health stability instead of memory.

Together the trio warns us: flat memory scores in school can predict flat coping scores later, so intervene early.

04

Why it matters

If you work with autistic clients, don’t wait for verbal working memory to “catch up.”

Build external supports like written lists, visual schedules, or rehearsal apps now.

Target self-advocacy skills so older kids can request these tools when classroom demands rise.

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→ Action — try this Monday

Add a visual digit-span rehearsal deck to your session and teach the student to use it before long instructions.

02At a glance

Intervention
not applicable
Design
quasi experimental
Sample size
151
Population
autism spectrum disorder, adhd, neurotypical
Finding
negative

03Original abstract

The aim of this study was to analyse the development of verbal working memory in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder and typically developing children. A total of 34 children with high-functioning autism, 72 children with attention-deficit/hyperactivity disorder and 45 typically developing children (age 9-16 years) were included at baseline and followed up approximately 25 months later. The children were given a letter/number sequencing task to assess verbal working memory. The performance of children with high-functioning autism on verbal working memory did not improve after 2 years, while improvement was observed in children with attention-deficit/hyperactivity disorder and typically developing children. The results indicate a different developmental trajectory for verbal working memory in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder and typically developing children. More research is needed to construct a developmental framework more suitable for children with autism spectrum disorder.

Autism : the international journal of research and practice, 2015 · doi:10.1177/1362361314524844