Reduced recruitment of inhibitory control regions in very young children with ADHD during a modified Kiddie
Mohammadreza Bayat1, Melissa Hernandez1, Madeline Curzon1
1Department of Psychology and the Center for Children and Families, Florida International University, Miami, FL, USA.
Insights
Researchers used a modified Kiddie-Continuous Performance Test (K-CPT) with fMRI to measure brain activity related to inhibitory control in young children with and without Attention-Deficit/Hyperactivity Disorder (ADHD). Findings reveal neurobiological differences in ADHD, though scanning challenges persist.
Area of Science:
- Neuroscience
- Developmental Psychology
- Pediatric Psychiatry
Background:
- Attention-Deficit/Hyperactivity Disorder (ADHD) symptom profiles change developmentally, complicating neurobiological assessment.
- Assessing inhibitory control network activity in young children (4-7 years) with ADHD is challenging due to a lack of child-friendly functional MRI (fMRI) paradigms.
- Existing research highlights the need for reliable methods to study brain function in early childhood ADHD.
Purpose of the Study:
- To adapt and validate a functional MRI (fMRI) paradigm for measuring inhibitory control in very young children.
- To investigate neurobiological differences in inhibitory control networks between children with ADHD and typically developing (TD) children aged 4-7 years.
- To explore the relationship between brain activity during inhibitory control tasks and behavioral performance.
Main Methods:
- A modified Kiddie-Continuous Performance Test (K-CPT) was administered during BOLD fMRI to 56 children with ADHD and 78 TD children (ages 4-7).
- Behavioral performance on the K-CPT was also assessed outside the MRI scanner.
- Movement artifacts were a significant challenge, with many participants failing to provide usable fMRI data.
Main Results:
- The modified K-CPT successfully elicited robust brain activity related to inhibitory control in scanned participants.
- Significant differences in brain activity were observed between ADHD and TD groups in regions including the inferior frontal gyrus, anterior insula, and cingulate cortex (p < .005, corrected).
- Increased right anterior insula activity correlated with improved response time and reduced variability in the TD group, but did not survive correction.
Conclusions:
- A modified K-CPT during fMRI can overcome some challenges in measuring inhibitory control in young children, providing insights into ADHD neurobiology.
- The study identified distinct patterns of brain activity associated with inhibitory control in young children with ADHD compared to TD peers.
- Further methodological advancements are needed to address motion-related challenges in fMRI studies of very young clinical populations.
Abstract:
Attention-Deficit/Hyperactivity Disorder (ADHD) symptom profiles are known to undergo changes throughout development, rendering the neurobiological assessment of ADHD challenging across different developmental stages. Particularly in young children (ages 4- to 7-years), measuring inhibitory control network activity in the brain has been a formidable task due to the lack of child-friendly functional Magnetic Resonance Imaging (fMRI) paradigms. This study aims to address these difficulties by focusing on measuring inhibitory control in very young children within the MRI environment. A total of 56 children diagnosed with ADHD and 78 typically developing (TD) 4-7-year-old children were successfully examined using a modified version of the Kiddie-Continuous Performance Test (K-CPT) during BOLD fMRI to assess inhibitory control. We also evaluated their performance on the standardized K-CPT outside the MRI scanner. Our findings suggest that the modified K-CPT effectively elicited robust and expected brain activity related to inhibitory control in both groups who were successfully scanned. Comparisons between the two groups revealed differences in brain activity, primarily observed in inferior frontal gyrus, anterior insula, dorsal striatum, medial pre-supplementary motor area (pre-SMA), and cingulate cortex (p < .005, corrected). Notably, for both groups increased activity in the right anterior insula was associated with improved response time (RT) and reduced RT variability on the K-CPT administered outside the MRI environment, although this did not survive statistical correction for multiple comparisons. The study also revealed continuing challenges for scanning this population-an additional 51 TD children and 78 children with ADHD were scanned, but failed to provide useable data due to movement. In summary, for a subsample of children, we successfully overcame some of the challenges of measuring inhibitory control in very young children within the MRI environment by using a modified K-CPT during BOLD fMRI, but further challenges remain for scanning in this population. The findings shed light on the neurobiological correlates of inhibitory control in ADHD and TD children, provide valuable insights for understanding ADHD across development, and potentially inform ADHD diagnosis and intervention strategies. The research also highlights remaining challenges with task fMRI in very young clinical samples.
