Sleep-Dependent Preservation of Emotional Memory: EEG and FMRI Investigations

Boston College, Chestnut Hill MA

Investigators

Abstract

Why do we sleep? We spend nearly one-third of our lives sleeping. Growing evidence suggests that one purpose of sleep is to strengthen memories formed during the day, particularly if these memories are emotional. With the support of the National Science Foundation, Dr. Elizabeth Kensinger (Boston College), Dr. Jessica Payne (Notre Dame), Dr. Bob Stickgold (Beth Israel hospital), and their students are assessing the role of sleep in memory formation, focusing on how memory for emotional experiences changes over sleep-filled delays. In particular, this research examines how sleep contributes to the maintenance of an emotional trade-off in memory, whereby people have difficulty remembering information presented in close proximity to an emotional item, although they remember the emotional item itself extremely well. This research combines electroencephalography (EEG), functional magnetic resonance imaging (fMRI), and behavioral methods in examing how different phases of sleep can lead to re-wiring of the neural circuits used to retrieve emotional memories, and how such re-wiring is influenced by the way an emotional event is first experienced. Memory trade-offs are magnified in those with depression and anxiety, and both disorders are associated with dramatic changes in sleep. Understanding the cognitive and neural mechanisms of the development and long-term preservation of these memory trade-offs is thus essential for knowledge of both healthy and dysfunctional emotional processing. Moreover, a longstanding question in cognitive neuroscience is how memory for emotional experiences is consolidated over time, and examining sleep-dependent effects on memory trade-offs provides a rare window through which to view the consolidation processes at work. Examining sleep effects on memory trade-offs also provides a means to answer one of the most mystifying questions in the field in sleep and memory research, which is how sleep-dependent consolidation processes preferentially select some aspects of an experience for long-term storage while allowing other aspects of memory to be forgotten. In addition to contributing to cognitive neuroscience and clinical psychology research, funding of this project enabling the growth of the neuroscience program at Boston College and helping launch a neuroscience focus at the University of Notre Dame. Moreover, this project is facilitating fruitful collaborations between Boston College, Beth Israel hospital, and Notre Dame, allowing students to benefit from training at all three sites. The project offers a rich research infrastructure for undergraduate student learning, providing them with exposure to EEG, fMRI, and behavioral assessment.