Hyperactivity, a core symptom of ADHD, is characterized by excessive motor activity and restlessness.
Children with ADHD often fidget, squirm, and struggle to sit still, especially during cognitively demanding tasks. The extent to which hyperactivity is a functional response to specific cognitive demands remains unclear.
Soto, E. F., Black, K., & Kofler, M. J. (2024). Is hyperactivity in children with attention deficit/hyperactivity disorder (ADHD) a functional response to demands on specific executive functions or cognitive demands in general? Neuropsychology, 38(8), 699–713. https://doi.org/10.1037/neu0000975
Key Points
- Hyperactivity in ADHD reflects the outcome of two factors: 1) a baseline elevated motor movement independent of environmental cognitive demands, and 2) additional elevations attributable to demands placed on executive functions, especially working memory and inhibitory control.
- Children with ADHD demonstrated moderately elevated hyperactivity compared to non-ADHD children (d=0.72), even under baseline conditions with minimal cognitive demands.
- When controlling for baseline hyperactivity, evoking demands on working memory and inhibitory control each produced large additional increases in hyperactivity for children with ADHD (Δd=0.80).
- Low cognitive demand conditions did not evoke additional hyperactivity beyond the elevated baseline levels for children with ADHD.
- Executive function demands exacerbate but do not fully explain hyperactivity in ADHD. There may be at least two pathways to hyperactivity – one caused by executive function demands and one by other factors needing further research.
Rationale
Hyperactivity is a core and impairing symptom in the clinical model of ADHD, but it remains unclear whether it is ubiquitous or a functional response to environmental demands challenging neurocognitive vulnerabilities (Kofler et al., 2016).
Prior research suggests hyperactivity may serve a compensatory function to increase arousal during cognitively demanding activities, especially those taxing underdeveloped executive functions (Rapport et al., 2009).
However, it is unknown if hyperactivity is evoked by cognitive demands in general or demands on specific executive functions.
This study aimed to comprehensively test these questions using objective actigraph measurement of hyperactivity across a battery of executive function and non-executive cognitive tasks.
Method
184 children ages 8-13 (119 ADHD, 65 non-ADHD) completed a counterbalanced battery of executive function (working memory, inhibitory control, set shifting) and non-executive cognitive tasks while wearing actigraphs to objectively measure motor activity.
Confirmatory factor analysis and structural equation modeling tested associations between ADHD diagnosis and hyperactivity across the task conditions.
Procedure
Children completed a battery of executive function and non-executive cognitive tasks in a counterbalanced order.
Baseline motor activity was measured during a low-demand Microsoft Paint activity at the beginning and end of each session.
Actigraphs measured activity level during all tasks.
Sample
The sample included 119 children carefully diagnosed with ADHD and 65 non-ADHD children (neurotypical and those with other psychiatric disorders).
Groups were matched on key demographics. Mean age was 10.4 years and 61 participants were girls.
Measures
- Actigraphs: Acceleration-sensitive devices that objectively measure frequency and intensity of motor activity. Worn on non-dominant wrist and both ankles.
- Working memory: Phonological and visuospatial working memory tasks
- Inhibitory control: Stop-signal and go/no-go tasks
- Set shifting: Global-local and number-color tasks
- Non-executive cognitive: Choice reaction time and alphanumeric naming speed
Statistical Analysis
Confirmatory factor analysis compared measurement models of hyperactivity across conditions.
Bifactor structural equation modeling then tested associations between ADHD diagnosis and hyperactivity factors.
Standardized mean differences (Cohen’s d) estimated the magnitude of ADHD/non-ADHD group differences in hyperactivity.
Results
The best-fitting model included a general baseline hyperactivity factor and three specific factors for hyperactivity during low cognitive demand, inhibitory control, and working memory conditions.
Compared to non-ADHD children, those with ADHD showed moderately elevated baseline hyperactivity (d=0.72) and large additional increases in hyperactivity during the working memory (Δd=0.80) and inhibitory control conditions (Δd=0.80) when controlling for baseline.
Low cognitive demand conditions did not evoke additional hyperactivity beyond baseline levels.
Insights
This study provides novel evidence that hyperactivity in ADHD reflects both elevated baseline motor activity and additional, large increases evoked specifically by demands on working memory and inhibitory control.
Interestingly, low cognitive demand tasks did not exacerbate hyperactivity beyond the already-elevated baseline.
This pattern suggests executive function demands worsen but do not fully account for hyperactivity in ADHD.
There appear to be multiple pathways, potentially executive and non-executive, that warrant further research to identify.
The findings extend prior work by using latent variable modeling in a large, carefully diagnosed sample of boys and girls to provide precise estimates of baseline-controlled, construct-specific hyperactivity.
Results align with and build upon intervention research showing that improving working memory, but not inhibitory control, reduces actigraph-measured hyperactivity in ADHD (Kofler et al., 2018; 2020).
Implications
Clinically, results suggest carefully considering whether a child’s hyperactive behaviors are impairing and need restricting versus serving a compensatory function for task completion, especially during executive-demanding activities.
Behavioral treatment should reward prosocial task completion rather than targeting motor activity.
Developing interventions to strengthen executive functions, particularly working memory, may help reduce hyperactivity.
For research, work is still needed to differentiate hyperactivity from developmentally-appropriate variability in activity level, including potential linear or curvilinear associations with daily functioning, to inform clinical cutoffs.
Understanding the full range of neurocognitive and contextual factors that exacerbate hyperactivity remains important for clarifying ADHD etiology and pathophysiology.
Strengths
This study had several methodological strengths, including:
- Relatively large, carefully evaluated clinical sample of boys and girls
- Latent variable approach to estimate construct-specific hyperactivity
- Objective, multi-site actigraph measurement of motor activity
- Multiple, counterbalanced tasks per neurocognitive construct
- Bifactor modeling to control baseline activity and compare construct-specific effects
Limitations
This study also had several methodological limitations, including:
- Sample was primarily White, male, and had high maternal education, limiting generalizability
- Unable to include set shifting in final models due to multicollinearity
- While comorbidities improved generalizability, their impact on hyperactivity needs further study
References
Primary reference
Soto, E. F., Black, K., & Kofler, M. J. (2024). Is hyperactivity in children with attention deficit/hyperactivity disorder (ADHD) a functional response to demands on specific executive functions or cognitive demands in general? Neuropsychology, 38(8), 699–713. https://doi.org/10.1037/neu0000975
Other references
Kofler, M. J., Raiker, J. S., Sarver, D. E., Wells, E. L., & Soto, E. F. (2016). Is hyperactivity ubiquitous in ADHD or dependent on environmental demands? Evidence from meta-analysis. Clinical psychology review, 46, 12-24. https://doi.org/10.1016/j.cpr.2016.04.004
Kofler, M. J., Sarver, D. E., Austin, K. E., Schaefer, H. S., Holland, E., Aduen, P. A., … & Lonigan, C. J. (2018). Can working memory training work for ADHD? Development of central executive training and comparison with behavioral parent training. Journal of Consulting and Clinical Psychology, 86(12), 964. https://doi.org/10.1037/ccp0000308
Kofler, M. J., Wells, E. L., Singh, L. J., Soto, E. F., Irwin, L. N., Groves, N. B., … & Lonigan, C. J. (2020). A randomized controlled trial of central executive training (CET) versus inhibitory control training (ICT) for ADHD. Journal of consulting and clinical psychology, 88(8), 738. https://doi.org/10.1037/ccp0000550
Rapport, M. D., Bolden, J., Kofler, M. J., Sarver, D. E., Raiker, J. S., & Alderson, R. M. (2009). Hyperactivity in boys with attention-deficit/hyperactivity disorder (ADHD): a ubiquitous core symptom or manifestation of working memory deficits?. Journal of abnormal child psychology, 37, 521-534. https://doi.org/10.1007/s10802-008-9287-8
Keep Learning
- Do you think the two proposed pathways (executive-related and baseline) fully capture the etiologies of hyperactivity in ADHD? What other factors may play a role?
- How might we further disentangle hyperactivity that serves a compensatory function versus hyperactivity that is impairing? What are the implications for assessment and treatment?
- Knowing that executive demands exacerbate hyperactivity, how would you design a classroom environment to optimize learning and minimize disruption for students with ADHD?
- Based on the finding that inhibitory control does not seem to drive hyperactivity beyond non-executive demands, do you think inhibitory control training has a role in ADHD treatment? Why or why not?
