Did acute stress change working memory in older adults?

Details

Earlier studies have shown that acute stress affects working memory in young adults, but its effects in older people are understudied. As seen with other types of memory, older people may be less sensitive to acute stress effects on working memory.

Researchers conducted two independent studies in healthy men and women aged 55–77 to investigate acute stress, induced using the Trier Social Stress Test (TSST), and cortisol in relation to working memory.

In study 1 (n = 63), women, but not men, improved after the TSST on Digit Span Forward, a measure of the memory-span component of working memory. They did not improve on Digit Span Backward, which measures both memory span and the executive component. Among women, cortisol levels at the time of memory testing were positively associated with memory span both before and after the TSST, and with the executive component only before the stress task.

In study 2 (n = 76), participants showed cortisol and salivary alpha-amylase (sAA) responses to the TSST, but stress did not affect performance on Letter-Number Sequencing (LNS), a task with high demands on the executive component of working memory. Neither cortisol nor sAA was associated with working memory.

The researchers concluded that circulating cortisol at the time of testing, rather than the stress response, affects memory span in older women, while stress and the post-stress increase in cortisol do not affect the executive component in older men and women. They said the findings provide further evidence that older people may be less sensitive to the effects of stress and stress-induced cortisol responses on memory processes.