Early Gamma-Band Activity During Interference Predicts Working Memory Distractibility in ADHD

Area of Science:

• Neuroscience
• Developmental Psychology

Background:

• Attention-deficit/hyperactivity disorder (ADHD) is characterized by working memory (WM) deficits and heightened distractibility.
• The gamma-band response (GBR) is an electrophysiological marker associated with attention and sensory processing, occurring early after stimulus onset.

Purpose of the Study:

• To investigate the neural underpinnings of distractibility in ADHD.
• To examine evoked gamma-band responses (GBR) during a working memory (WM) task with distraction in boys with ADHD compared to healthy controls.

Main Methods:

• Electroencephalography (EEG) was used to measure the evoked 40 Hz-gamma-band response (GBR).
• 16 boys diagnosed with ADHD and 20 typically developing boys (ages 10-14) participated.
• Participants completed a working memory task that included distracting stimuli.

Main Results:

• Boys with ADHD exhibited significantly higher occipitally evoked 40 Hz-GBR during distraction compared to controls.
• The magnitude of the GBR during distraction was negatively correlated with measures of interference control in the ADHD group.

Conclusions:

• These findings suggest that individuals with ADHD are affected by distracting information at an early stage of sensory perception.
• Elevated GBR in ADHD during distraction may reflect an impaired ability to filter irrelevant sensory input.