Response inhibition in adults with autism spectrum disorder compared to attention deficit/hyperactivity disorder.
Adults with autism stop accurately but slowly; adults with ADHD stop quickly but erratically—adjust timing and error contingencies for each profile.
01Research in Context
What this study did
Sofronoff et al. (2011) compared how well adults with autism, adults with ADHD, and typical adults stop themselves from hitting the wrong key.
They used simple computer go/no-go and stop-signal tasks. No extra coaching was given.
What they found
Adults with autism were slow but accurate. They hit the brakes late, yet rarely made the wrong response.
Adults with ADHD were fast but sloppy. They hit many wrong keys, showing an impulsive style.
Both groups looked different from typical adults, but in opposite ways.
How this fits with other research
Bramham et al. (2009) saw the same split picture two years earlier. They found ADHD adults struggle only with stopping, while ASD adults also struggle to start, plan, and switch.
Two child studies seem to clash. Early et al. (2012) say autistic kids can stop a prepotent response just fine. Sanderson et al. (2013) add that they only fail when the task adds conflict. Kate’s adult data solve the clash: accuracy stays intact, speed drops.
Later meta-analyses by Eussen et al. (2016) and Tonizzi et al. (2022) pool many studies and confirm a medium-sized inhibition deficit in ASD. Kate’s slow-but-accurate adults sit inside that average.
Adams et al. (2021) zoom in on the mechanism. They show ASD learners fail because they don’t slow down before the signal, not because they react late. Kate’s long stop times match this proactive-control story.
Why it matters
When you test an adult with autism, give extra time and ignore fast reaction norms. They will likely stop, just later. For adults with ADHD, watch for fast guesses and build in response cost or delay prompts. The same task can flag two different treatment paths.
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02At a glance
03Original abstract
Autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD) are hypothesised to involve core deficits in executive function. Previous studies have found evidence of a double dissociation between the disorders on specific executive functions (planning and response inhibition). To date most research has been conducted with children. No studies have directly compared the stable cognitive profile of adults. It was hypothesised that adults with ASD would show generally intact response inhibition whereas those with ADHD would show more global impairment. Participants were 24 adults aged 18-55 with high functioning ASD, 24 with ADHD, and 14 age and IQ matched controls. Participants completed three standardised measures of response inhibition. Participants with ASD had generally intact response inhibition but slow response latencies, possibly due to deficits in response initiation. Adults with ADHD did not show the more global impairments hypothesised. There were some significant differences between the clinical groups across measures of inhibition. In terms of performance style, adults with ASD were slow and accurate whilst those with ADHD showed an impulsive style.
Journal of autism and developmental disorders, 2011 · doi:10.1007/s10803-010-1113-9