Beyond Neural Noise: Critical Dynamics Predict Slower Reaction Times in Adults With and Without ADHD

Area of Science:

• Neuroscience
• Cognitive Science
• Computational Psychiatry

Background:

• Neural variability was historically viewed as noise obscuring brain signals.
• Increased reaction-time variability (RTV) in attention deficit hyperactivity disorder (ADHD) was linked to signal-to-noise ratio changes.
• Variability can possess underlying statistical structure beneficial for information processing.

Purpose of the Study:

• To investigate if changes in neural criticality and oscillatory dynamics precede slower behavioral responses in ADHD during a continuous performance task.
• To differentiate between structured and random neural variability in ADHD.

Main Methods:

• Analysis of neural dynamics and oscillatory patterns during a bimodal continuous performance task.
• Comparison of neural activity preceding slow versus fast responses in individuals with and without ADHD.
• Examination of criticality and edge-of-synchrony principles.

Main Results:

• Neural dynamics shifted toward criticality prior to slower responses in both ADHD and control groups.
• This suggests that increased variability in ADHD and attention lapses may involve structured variability, not random noise.
• Findings challenge the edge-of-synchrony criticality as a sole explanation for neural variability and performance, especially at the between-subject level.

Conclusions:

• Neural dynamics shift towards criticality before slow reaction times in adults with and without ADHD.
• ADHD dynamics appear closer to criticality irrespective of response type, indicating a distinct attractor state.
• Relying solely on between-subject correlations may limit understanding of neural mechanisms underlying behavioral variability.