The impact of visual distraction on episodic retrieval in older adults.

Impairment in long-term memory is one of the most salient alterations in cognitive aging. Findings of age-related deficits in source monitoring and recollection have revealed a selective decline in memory for detailed information. The underlying mechanism of this phenomenon is not well understood. We hypothesized that the influence of task-irrelevant visual stimuli present in our environment interferes with retrieval of detailed memories more for older than younger adults. We compared memory performance on a recall test for visual details when older adult participants' eyes were closed versus performance when their eyes were open and irrelevant visual stimuli were presented. The results showed that the presence of irrelevant visual information diminished long-term memory performance based on an objective measure of recollection for visual details. Comparison of the current results to findings from our earlier study using the same experimental paradigm with younger adults revealed that visual distraction disrupted recollection of relevant details to a greater degree in older than younger adults. This result suggests that visual distraction overwhelms older adults' declining cognitive control resources that are instrumental in the retrieval and selection of mnemonic details. More generally, these findings explicate a mechanistic basis for selective impairment of recollection in normal aging.