Poster #14 - ADHD symptom burden has distinct relations to brain activity during different facets of executive function

• In Event: 1-115 - Poster Session 03
  In Poster Session: PS 03 Section - Biological Processes: Neuroscience and Genetics

Integrative Statement

Attention deficit hyperactivity disorder (ADHD) is a prevalent childhood disorder marked by hyperactivity and/or inattention symptoms. ADHD may also relate to impaired executive functions (EFs), which are cognitive processes that orchestrate goal-directed behaviors. Factor analyses of EF performance have found related but distinct domains including switching between tasks, inhibiting planned responses, and holding or updating information in working memory (Miyake, 2000). EFs may mediate the impacts of ADHD symptom burden on academic achievement and mental health, but have often only been studied through single tasks per sample. Further, most studies have used groups based on presence or absence of diagnosis rather than on symptom burden. Thus, it remains unclear if ADHD symptom burden uniformly impacts EF task performance or brain activity across different EFs domains.

For the current study, we collected continuous measures of ADHD symptom burden (parent-rated Conners-3 scale; Conners, 2008) from a diverse group of participants (age 8-18 years) with and without an ADHD diagnosis. Participants performed three EF tasks in the MRI scanner. We used a cognitive flexibility task for switching (N=66, mean age 12.72), an N-back task to examine updating (N=63, mean age 12.65), and a stop-signal task for response inhibition (N=57, mean age 13.2). There were 54 individuals with data for all three tasks (mean age 13.06). We ran a whole-brain correlational analysis between ADHD symptom burden scores and neural activity during each EF task.

We found that ADHD symptom burden was differently related to individual differences in neural activity across EF tasks. During the updating task (contrast: 2-back vs. baseline), there was a positive relation between neural activity and ADHD symptom burden in the ventromedial prefrontal cortex and right frontal pole. During the inhibition task (contrast: stop vs. baseline), there was a negative relation with ADHD burden in the superior parietal lobe. Under more restrictive contrasts, we found a positive relation between ADHD burden and activity in the caudate during updating (2-back vs. 1-back), and a positive relation between symptom burden and activity in the postcentral gyrus during inhibition (Stop vs. Go). We found no relation between the switching task and our measure of ADHD symptom burden. These correlational effects remained stable when controlling for age. Overall, these findings indicate that 1) ADHD symptom burden appears to have different relations to different facets of EF within the same children; 2) studying ADHD symptom burden using continuous measures can reveal subtle effects that binary diagnoses may not; 3) distinct relations between ADHD and different EFs may explain the distributed brain regions or networks implicated in the neuroimaging literature on ADHD and EF abilities. This work has the potential to inform interventions based on ADHD symptom burden, particularly in attention-demanding settings.

Authors

• Tehila Nugiel, The University of Texas at Austin
  Presenting Author

• Mary Abbe Roe, The University of Texas at Austin
  Non-Presenting Author

• Laura Engelhardt, The University of Texas at Austin
  Non-Presenting Author

• Mackenzie E Mitchell, The University of Texas at Austin
  Non-Presenting Author

• Jessica A Church, The University of Texas at Austin
  Non-Presenting Author