Older Adults are Impaired by Distractors Presented During Working Memory Encoding

Working memory performance declines across the lifespan, partly due to greater vulnerability to environmental distraction. Successful working memory relies on resistance to distractors, which may enter memory due to ineffective filtering during simultaneous presentation with targets (i.e., during encoding), or due to insufficient ability to ignore them during maintenance. Prior research has offered mixed conclusions about whether impaired distractor suppression contributes to older adults’ working memory deficits. Across three behavioral experiments, we found consistent evidence that older adults were more vulnerable to distractors presented during encoding than during maintenance. Distractor familiarity had limited impact on performance, whereas low-salience distractors presented during encoding produced robust declines in accuracy and increases in reaction time. These results demonstrate that encoding-stage distraction is a key driver of working memory disruption in aging and highlight the cost of perceptually subtle, yet temporally intrusive, distractors.