The Evolution of Memories Across Wake and Sleep

Goal 1: How do memories evolve across wake and sleep? The investigators are interested in how specific memories are selected for change across periods of wake and sleep, and in characterizing the manner in which those memories change. There has been research into broad areas of memory, such as procedural and declarative memory, but other forms of memory, such as semantic memory, remain unexplored, as well as different subtypes of memory within these broad areas. Additionally, it is presently unknown how memories are selected for subsequent processing during sleep and wake. The investigators aim to characterize which memories change, how they are selected, and how they change differently over periods that include sleep versus periods during which participants remain awake. Goal 2: How are these changes reflected behaviorally and in the EEG signal? The investigators will employ and develop specific behavioral and electrophysiological tasks and measures that allow one to probe the state of a particular type of memory and determine how it changes over periods of wake and sleep. EEG signals may be informative about the status of a memory during behavioral performance as well as during both waking and sleeping offline states. Goal 3: What stages and features of sleep affect memory evolution? In the cases in which sleep in particular is found or suspected to influence memories in a unique way, the investigators will assess which stages and features of sleep are involved in that evolution. Generally, this will be accomplished by correlating measures such as time spent in a sleep stage, prominence of particular brain oscillations, or density of spindles with changes in behavior or in other EEG metrics