Behavioral inhibition and activation as a modifier process in autism spectrum disorder: Examination of self-reported BIS/BAS and alpha EEG asymmetry.
A quick reward-avoidance survey plus alpha EEG can map anxiety and autism severity in teens.
01Research in Context
What this study did
Crossman et al. (2018) asked teens with autism to fill out two short surveys. One measures how much they want to go after rewards (BAS). The other measures how much they avoid threats (BIS).
While the teens answered, the team also recorded tiny brain waves from each side of the head. They looked at alpha rhythm size to see if the two sides matched.
Last, they checked whether survey scores and brain waves together predicted autism severity and anxiety.
What they found
Higher reward drive (BAS) was linked to a special alpha pattern: one side showed more activity than the other.
That reward drive helped explain why the brain pattern and autism severity were connected. In plain words, wanting rewards may shape both brain balance and day-to-day symptoms.
BIS and BAS scores also tracked with anxiety complaints, showing these quick surveys tap real-life stress.
How this fits with other research
Harrop et al. (2024) widened the age range and added neurotypical kids. They found the same BIS-anxiety link, proving the survey works from preschool to high school.
A Boyd et al. (2024) followed autistic children for one year. BIS scores moved as kids grew, showing the tool is sensitive to change and ready for treatment tracking.
Murphy et al. (2014) used the same alpha marker but looked at distractibility. They saw weak alpha control in autism, backing the idea that uneven alpha activity is a core part of the diagnosis.
South et al. (2011) studied risk-taking and inhibition years earlier. Their work hints that anxiety plus low IQ can shrink safe risks, foreshadowing how inhibition and anxiety mingle in the new data.
Why it matters
You can add the 20-item BIS/BAS survey to your intake packet today. It takes two minutes and gives you a window into both anxiety and motivation style. Pair it with simple EEG if you have access, but even alone it helps explain why some clients chase rewards while others freeze. Use yearly re-scores to show families how flexibility and anxiety shift over time.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Hand out the BIS/BAS forms at intake and note any high BAS scores as a sign to build anxiety coping plans.
02At a glance
03Original abstract
The Modifier Model of autism spectrum disorder (ASD) suggests that phenotypic variability within ASD is rooted in modifier processes, such as the behavioral inhibition system (BIS) and behavioral activation system (BAS). Among a sample of 53 adolescents with ASD, this study examined associations between (a) self-reported BIS/BAS and frontal and parietal alpha electroencephalogram asymmetry and whether these indices related to (b) ASD severity (via the Autism Quotient), and/or (c) co-occurring anxiety and attention-deficit hyperactivity disorder (via Youth Self Report and Child Behavior Checklist). Findings showed that alpha asymmetry was associated with self-reported BAS scores, such that greater BAS was related to greater right-frontal hemisphere activation and relatively greater left-parietal hemisphere activation. Additionally, associations emerged between ASD severity and self-reported BAS and alpha asymmetry, and between anxiety symptoms and self-reported BIS and alpha asymmetry. Furthermore, mediation analyses revealed that BAS mediated the association between asymmetry and autism severity. Therefore, alpha asymmetry and BIS/BAS activity may provide insight into how ASD presents in adolescence as well as who might be at greater risk for developing co-occurring psychopathologies. This study highlights the importance of considering motivational systems to elucidate individual differences among youth with ASD and working toward the longer term goal of better understanding differential responses to treatment. Autism Research 2018, 11: 1653-1666. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Differences in the likelihood to avoid (behavioral inhibition system; BIS) or approach (behavioral activation system; BAS) situations are thought to relate to patterns of brain activity (via electroencephalogram asymmetry asymmetry). This study revealed that these tendencies may influence the presentation of autism spectrum disorder (ASD) and symptoms of anxiety in adolescents with ASD.
Autism research : official journal of the International Society for Autism Research, 2018 · doi:10.1002/aur.2016