People spend nearly one-third of their lives sleeping, and growing evidence suggests that one purpose of sleep is to strengthen memories formed during the day, particularly if these memories are emotionally salient. However, the majority of this evidence stems from data on college-age research participants that are not representative of the broader population. Little is known about sleep and memory function in middle age. This research will examine how sleep contributes to selectivity effects in memory in middle-aged people. One example of memory selectivity is the tendency to remember emotional information extremely well, often at the expense of neutral information. This research builds on prior findings, of the role of sleep in selective consolidation of emotional memories in young adults. This project combines EEG, fMRI, and behavioral approaches to examine how different phases and features of sleep can re-wire neural circuits used to retrieve emotional memories; how such re-wiring may be influenced by the way an emotional event is first experienced; and whether such processes differ as a function of age. The research will provide educational and training opportunities at two universities, and will promote healthy aging through regional and national outreach.
Sleep promotes memory for emotional components of complex scenes while conferring no benefit to memory for neutral, contextual elements. Moreover, sleep preferentially consolidates information that attracts overt attention and provokes a physiological arousal response during encoding. During retrieval, these effects of sleep-based consolidation are reflected in enhanced activity and connectivity within limbic circuitry. This project investigates whether sleep continues to aide in the selective consolidation of emotional information in adults over the age of 35. If so, do correlations between emotion, brain connectivity, sleep, and memory stay stable with age? If age disrupts selective consolidation, what changes in sleep architecture and/or encoding-related processing are most predictive of that disruption, and at what age do those changes begin to occur? This project further characterizes downstream consequences of sleep-dependent memory consolidation by examining neural circuitry involved during retrieval, fMRI will reveal whether age influences the sleep-related enhancement in limbic activity and connectivity during memory retrieval. This research will develop a foundational, basic-science understanding of sleep and emotional memory consolidation in middle age, and will inform development of sleep-based interventions to improve mnemonic and affective function as adults age.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
