Current Environment:

Research Findings

Here is a summary of some of the recent (and exciting!) results to come out of the Arnett Lab studies.

Reduced Cognitive Control Explains the Association Between Atypical Brain Activation and Neurodevelopmental Disorder Symptoms

Children with neurodevelopmental disorders (NDDs), such as attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), often have weaker cognitive control skills. Cognitive control describes the ability to regulate behaviors, such as planning, maintaining attention, and inhibiting impulses. Dr. Peisch and Dr. Arnett recently completed a study that examined the link between brain activity (measured with EEG), cognitive control, and neurodevelopmental symptoms.

They found that cognitive control fully mediated the association between brain activity and neurodevelopmental symptoms. These findings are shown in the figure below. Drs. Peisch and Arnett interpret these results to suggest that the EEG differences seen in children with ADHD may result from atypical development of brain networks that also support cognitive control, which in turn explains symptoms commonly observed in children with neurodevelopmental disorders (e.g., difficulty shifting attention away from a preferred task). As cognitive control skills are malleable and may be strengthened through interventions, these findings are important for the clinical care of children with ADHD and other related neurodevelopmental disorders.

Neural Oscillatory Patterns Predict ADHD Diagnosis and Methylphenidate Response in Children

The aperiodic spectral slope is an EEG-acquired measure of background brain activity. In a poster presented at a conference for the American Professional Society of ADHD and Related Disorders (APSARD) in January 2022, Dr. Arnett and colleagues reported that children with ADHD show flatter aperiodic slopes in comparison to typically developing controls during a lights-off resting condition, but not in a lights-on condition. Overall, the brains of control children appeared to have adjusted their spectral slope across all conditions whereas the ADHD children’s brains did not.

Children with ADHD Do Not Recognize Errors as Readily as Control Children

In a peer-reviewed article published in the Journal of the International Neuropsychological Society, led by Dr. Arnett in collaboration with graduate students Candace Rhoads and Tara Rutter, we examined a phenomenon called “post-error slowing.” Post-error slowing happens during tasks requiring repeated responses, such as pressing a corresponding key on a keyboard every time the letter “X” or “O” is presented on the screen. When people make a mistake during one of these tasks, they tend to press the key more slowly at the next trial; in other words, their response time slows after they make an error. However, children with ADHD do not slow down after an error as much as children without ADHD do. People have wondered whether this is due to not recognizing their mistakes, or difficulty adjusting their behavior, or both. We showed (with the help of ACTIVE Study participants!) that the main reason is that children with ADHD do not recognize their mistakes as readily as children without ADHD.

Brain Signatures of Error Recognition

Next, we will write about what is happening in children’s brains when they make a mistake. Here is a sneak preview — the Error Related Negativity component (measured with EEG) is much more pronounced for non-ADHD compared to ADHD participants. Could that explain the lack of post-error slowing in ADHD?

Figure showing Error Related Negativity component (measured with EEG) is much more pronounced for non-ADHD compared to ADHD participants

Co-existing Psychiatric Symptoms in ADHD

In a report published by the Journal of Attention Disorders, graduate student Tara Rutter and Dr. Arnett report that certain temperament traits are associated with increased likelihood that a child with ADHD will have co-existing psychiatric symptoms. For example, children with ADHD who have more negative affect, less self-control, and are more outgoing are more likely to have co-existing oppositional behaviors. Children with ADHD who have negative affect, but typical levels of self-control and extroversion, are more likely to have co-existing anxious symptoms.