Name: Emily Hokett

School of Psychology Master's Thesis Defense Presentation

Date: Friday, August 17, 2018

Time: 2:00pm

Location: JS Coon 217

Advisor: 

Professor Audrey Duarte, Ph.D. (Georgia Tech)

Thesis Committee Members:

Professor Audrey Duarte, Ph.D. (Georgia Tech)

Professor Paul Verhaeghen, Ph.D. (Georgia Tech)

Professor Mark Wheeler, Ph.D. (Georgia Tech)

Title: General Sleeping Patterns May Predict Associative Memory Retrieval

Research has shown that sleep is essential for memory consolidation. However, the effects of habitual sleep quality on memory performance are unclear, especially regarding age-related differences in brain function. We hypothesized that sleep quality would mediate the relationship between retrieval-related neural oscillations and memory performance across age groups. We also hypothesized that these relationships may differ across age groups such that sleep quality may differentially affect young and older adults. We investigated these relationships using one week of sleep data collection, neuropsychological testing, a paired-associate memory task, and retrieval-related electroencephalography (EEG). We found that memory accuracy was positively associated with sleep quality across age groups. However, measures of sleep fragmentation (e.g., wake after sleep onset) and memory performance were only significant in the older adult sample. In addition, we found relationships between measures of sleep quality and measures of oscillatory power that supported memory performance. For older adults, there was a positive relationship between total sleep time and theta synchronization for the difference between hits and misses. The same relationship was found in young adults for theta synchronization from baseline. This finding suggests that maintaining sufficient sleep is particularly important for memory-related neural function. While our data demonstrate that sleep quality is important for memory performance in both young and older adults, older adults may be particularly sensitive to sleep quality. Prior research has shown that lifestyle factors such as maintaining good sleep quality and moderate physical activity may improve memory in older adults. Consistent with these findings, we found that sleep quality was positively associated with associative memory. This study extends the current literature with the finding that good sleep quality may support greater functional activity in neural correlates important for memory accuracy