Internal memory costs following cognitive offloading in younger and older adults

Older adults rely on cognitive offloading to compensate for memory decline. However, research in younger adults has shown that offloading weakens internal memory because individuals disengage from encoding externally saved information. We examined whether similar costs occur in older adults. Forty older and forty younger adults studied four lists of 20 words. Following an internal memory baseline block, participants wrote down words during study and used their list at test in two consecutive blocks. In a critical fourth block, participants wrote down words during study but were tested without the list. Half of the participants were told the list would be inaccessible at test and therefore relied on internal memory, while the remaining participants expected list access. Participants also reported their encoding strategies and confidence in list availability. Younger adults outperformed older adults when relying on internal memory, yet both groups performed comparably with external aids. Critically, in both age groups, the expectation of list availability was associated with reduced strategy use and poorer memory performance, with strategy use partially mediating the impact of cognitive offloading on memory performance. Older adults, like younger adults, incur an internal memory cost when offloading information, highlighting the importance of maintaining external store access.