Objective: Learning unfolds in distinct stages--acquisition, consolidation, and maintenance--shaped by cognitive mechanisms such as saliency processing, interference control, and sustained attention. ADHD in adults is associated with deficits in these cognitive processes, which in turn might lead to learning difficulties. Method: Using a novel protocol that incorporates a visual attention task with gestalt-image targets and primer distractors, we investigated these cognitive mechanisms across different stages of learning in 53 adults diagnosed with ADHD and 18 neurotypical Controls. Results: Our findings reveal that adults with ADHD exhibit reduced neural activations in the occipital and parietal areas, indicating diminished bottom-up visual processing and challenges in handling distractions. Nevertheless, individuals with ADHD demonstrate increased frontal activity in the late stages of visual processing, suggesting compensatory mechanisms employed by the group. Behaviorally, both groups achieve comparable performance, though ADHD participants do so at the expense of greater variability and attentional lapses. Furthermore, while Controls reach the plateau already after the acquisition phase, the ADHD group is gradually improving its performance throughout the experiment. Conclusion: These findings demonstrate that adults with ADHD can acquire and retain new skills but do so through different--and usually more effortful--pathways. By mapping neural and behavioral dynamics onto learning stages, this study offers a more nuanced framework for learning in ADHD and supports the development of phase-specific intervention strategies.