OSCILLATORY SIGNATURES OF VISUAL ATTENTION AND WORKING MEMORY IN ADULTS WITH ADHD

Attention-deficit/hyperactivity disorder (ADHD) is characterized by symptoms of inattention and/or hyperactivity–impulsivity. Event-related oscillations (EROs) derived from electroencephalography (EEG) provide time- and frequency-specific indices of neural processing and offer a powerful framework for investigating attention and working memory mechanisms. In particular, theta and alpha oscillations are closely linked to attentional control and working memory and typically increase with cognitive load. Building on this framework, we examined theta and alpha ERO responses during visual attention and working memory processing in adults with ADHD. EEG was recorded from adults with ADHD and age-matched healthy controls during a visual oddball task that engaged visual attention and working memory processes. Event-related power spectra were analyzed for theta (4–7 Hz) and alpha (8–13 Hz) frequency bands, and task performance was assessed behaviorally. Statistical analyses were conducted using repeated-measures ANOVA and Mann–Whitney U tests (p < 0.05). Compared with healthy controls, the ADHD group exhibited significantly increased alpha power in response to target stimuli (p < 0.05) and showed a trend toward increased theta power. Behavioral performance during the oddball task did not differ between groups. Despite comparable task performance, adults with ADHD demonstrated enhanced responses in theta and alpha bands, consistent with altered or compensatory neural engagement supporting visual attention and working memory in ADHD.