Interactions of Emotion and Memory in the Aging Brain: Neural and Psychological Correlates

Memory and aging across cultures

Memory declines are commonly reported with age, but the majority of research has been conducted with narrow segments of the world's population. We argue for the importance of considering culture in the study of cognitive aging in order to have a representative, accurate understanding of the effects of aging on memory. Limited research thus far investigates the effects of culture on the use of categories and the self in memory with age, finding that cultural differences tend to be larger for older than younger adults. Frameworks drawing on top-down and bottom-up processes may account for when more or less cultural variation would be expected in cognitive performance. Promising future research directions include socio-emotional memory and expanding samples to address global inequities.

Improvement of mnemonic discrimination with acute light exercise is mediated by pupil-linked arousal in healthy older adults

Physical exercise has positive impacts on hippocampal memory decline with aging. One of the postulated neurobiological mechanisms of the decline is reduced catecholaminergic projections from the locus coeruleus to the hippocampus. Recent human studies revealed that very light exercise rapidly enhances memory and pupil diameter, which suggests that light exercise may improve memory via neural circuits involved in the ascending arousal system, including the locus coeruleus, even in older adults. Thus, we aimed to clarify the effects of a single bout of light-intensity exercise (60% ventilatory threshold) on mnemonic discrimination performance, an index of hippocampal memory function, in healthy older adults using a randomized crossover design. Pupil diameter was measured during exercise as a physiological marker of the ascending arousal system. Discrimination of highly similar stimuli to the targets improved after exercise when compared to the resting control performance. Importantly, causal mediation analysis showed that pupil dilation during exercise mediated the memory improvement. These results suggest that brief light exercise rapidly enhances memory, possibly by upregulating the ascending arousal system.