Project Summary The overarching goals of this project are to illuminate the nature and functions of episodic memory by examining how retrieval of episodic memories supports cognitive functions that extend beyond simple recall of past events, such as imagining future experiences, solving everyday problems, and making inferences about the links among related events. Recent evidence indicates that the same core brain network is involved in both remembering past experiences and imagining or simulating hypothetical future experiences. The proposed experiments will use novel cognitive tasks and neuroscience-based measures, including both functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS), to elucidate how specific regions within this core network support constructive uses of episodic retrieval that underly future thinking, problem solving, and associative inferences. The studies will also examine how some of these adaptive functions can also lead to errors in episodic remembering. One set of studies will use a novel fMRI pattern similarity approach to clarify how two key regions in the core brain network – the hippocampus and angular gyrus – reinstate episodic information from past experiences when people imagine various kinds of future experiences. TMS will provide converging evidence by targeting hippocampal activity, which should specifically impact episodic reinstatement. A second set of studies will use a similar combination of fMRI pattern similarity and TMS approaches to revealing, for the first time, how episodic information is reinstated when people try to address everyday personal problems, including problems that are personally worrisome. These studies will draw on novel behavioral paradigms that recruit episodic retrieval processes during personal problem solving. A third set of experiments will attempt to identify the neural mechanisms underlying memory errors that result from adaptive use of episodic retrieval processes that support the ability to make associative inferences about the relations among events by combining novel behavioral paradigms with fMRI pattern similarity analysis. Overall, these experiments should enhance understanding of mechanisms involved in episodic retrieval, simulation, and problem solving by helping to refine recently novel measures developed in recent research, and could also provide insights that are relevant to clinical conditions in which episodic retrieval and simulation deficits contribute to impairments in everyday cognitive function.