¹University of Lausanne, Neuroheuristics Research Group, Lausanne, Switzerland

Background: Adult Attention-Deficit/Hyperactivity Disorder (ADHD) is characterized by deficits in executive control and attention, accompanied by atypical electrophysiological activity within frontoparietal attention networks. These networks support alerting, orienting, and executive control functions and are commonly indexed by ERP components such as the N100 and P300. Although stimulant medication can partially normalize these processes, evidence for training-induced neural plasticity in adult ADHD remains limited.

Aims & Objectives: This study investigated whether adaptive working memory training induces plastic changes in attention network dynamics, as measured behaviorally and via EEG during the Attention Network Task (ANT), in adults with ADHD.

Method: Three groups were studied: non-medicated adults with ADHD, adults with ADHD receiving methylphenidate (MADHD), and neurotypical controls. Participants completed 20 days of adaptive Dual n-back training (≈30 min/day). EEG was recorded during ANT performance before and after training. Behavioral measures included reaction times and alerting, orienting, and executive conflict effects. ERP indices—fractional area latency (FAL), mean amplitude (MA), and fractional peak latency (FPL)—were extracted from frontal and parietal electrodes across ANT condition bins corresponding to alerting, orienting, and executive conflict processing.

Results: Behavioral alerting and orienting effects remained stable across sessions, whereas executive conflict resolution improved significantly following training in both ADHD groups. EEG analyses revealed training-related plasticity within attention networks. For the P300 component associated with executive control, adaptive training increased parietal MA and reduced FAL and FPL, indicating faster and stronger recruitment of executive attention resources. These effects were observed in both ADHD groups but were attenuated in the MADHD group, consistent with partial baseline normalization by stimulant medication. Significant group × condition interactions showed that incongruent (high-conflict) targets elicited the largest post-training neural gains. For the N100 component linked to early alerting and orienting, training produced increased MA and shortened FPL over frontal–central regions, reflecting enhanced early attentional engagement. Again, effects were less pronounced in medicated participants, suggesting ceiling effects related to pharmacological attentional stabilization.

Discussion & Conclusions: Adaptive working memory training induces measurable EEG markers of attention network plasticity in adult ADHD. Training enhanced neural efficiency and engagement across both early (N100) and late (P300) attentional processes, with the strongest effects observed in unmedicated individuals. These findings provide convergent behavioral and electrophysiological evidence that working memory training strengthens cortical mechanisms underlying executive and attentional control, supporting its use as a complementary or alternative non-pharmacological intervention in adult ADHD.