Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental condition affecting 2.5–6.7 % of adults and characterized by difficulties in attention regulation, impulse control, and executive functioning. Theories of visual attention differentiate between top-down (goal-directed) control and bottom-up (stimulus or saliency-driven) processes. While early research emphasized a general attention deficit in ADHD, more recent evidence indicates that bottom-up mechanisms may normalize with age, while top-down control deficits persist into adulthood.

In this study, we compare the visual search performance of adults with and without ADHD. For this we adapt a visual-search task from Zhaoping and Guyader where participants search for a uniquely tilted target bar among distractors. Complexity of the target and distractors will be varied to investigate how ADHD-related attentional deficits interact with both low-level feature detection and high-level object recognition. Reaction-time, accuracy, and eye-tracking data will be used to capture visual attention and search strategies.

According to the V1-Saliency-Hypothesis (V1SH) simpler feature search should leverage bottom-up processing while more complex conditions require top-down engagement because the saliency contrast of the target is weaker. Based on previous studies we expect individuals with ADHD to show a higher variability in performance and overall reduced top-down control (increased influence of distractors) as well as heightened sensitivity to bottom-up salience (greater attraction by salient stimuli).

By isolating top-down and bottom-up components of visual attention, we aim to clarify their contribution to attentional dysregulation in ADHD and hopefully explain some of the variability of prior results.