PUB - Publikationen an der Universität Bielefeld

Visual search becomes slower with aging, particularly when targets are difficult to discriminate from distractors. Slower reaction times may originate from multiple distractor rejection processes that contribute independently to visual search performance: dwelling, skipping and revisiting, measurable by eye-tracking. The present study investigated how age affects each of the distractor rejection processes, and how these contribute to the final search times. In a sample of Dutch healthy adults (19-85 years), we measured reaction times and eye-movements during a difficult (inefficient) target present/absent visual search task, with varying target-distractor similarity and visual set size. We found that older age was associated with longer dwelling and more revisiting of distractors, which contributed to slower reaction times in target absent trials. This suggests that older adults need more resources or time to process distractors (resulting in longer dwelling) and have limited visual memory for visited locations (resulting in more revisiting). By contrast, skipping was unaffected by age and contributed little to the final search times. Under conditions of poor guidance, participants appear to skip only few distractors independently of their age. In conclusion, our findings show that dwelling and revisiting have a major contribution to age-related slowing in difficult visual search, while skipping is largely negligible.