Background <p>Perceptual load is a major determinant of visual attentional selection patterns, and dynamic stimuli are salient bottom-up distractors. The present study investigated how dynamic stimuli, presented under different perceptual loads, impact the process of visual attentional selection.</p> Methods <p>Fourteen participants (8 females and 6 males) were measured on task performance (reaction time and correctness) and event-related potentials while searching for visual exploratory task in a perceptual load paradigm.</p> Results <p>In terms of behavioral performance, longer reaction times were required for the visual exploratory task under high perceptual load, whereas a trend suggestive of attentional capture reversal emerged under low perceptual load. Regarding ERP components, the P1 amplitude was more positive in the response to dynamic stimuli, while the N1 amplitude was more negative when dynamic stimuli were absent. The P3 amplitude was more positive in the presence of dynamic stimuli than in their absence and was also more positive under low perceptual load than under high perceptual load.</p> Conclusions <p>This study found that N1 and P1 components were more sensitive to dynamic stimuli and insensitive to perceptual loads, while the P3 component effectively assessed both perceptual loads and dynamic stimuli. These variations reflect differential attentional allocation. Based on these findings, adapting interface displays according to gaze direction and perceptual load level can inform the design of user interfaces, such as those in navigation systems, educational materials, and assistive devices.</p> Trial registration <p>This study was approved by the Ethics Committee of Chiba University Graduate School of Engineering (acceptance number: R4-20, Acceptance date: March 22, 2023).</p>