The hallmark feature of episodic memory is the ability to link events with their temporal and situational contexts. This ability allows for memories to be truly autobiographical, and failures of episodic memory are signs of normal aging and neurodegenerative disease. The proposed research aims to illuminate the neural and cognitive mechanisms underlying human episodic (contextually-mediated) memory through both computational modeling and the analysis of intracranial and scalp electroencephalographic (EEG) recordings taken as neurosurgical patients and healthy adults search their memory for recently studied material. Using a model-based approach coupled with multivariate pattern analysis applied to electrophysiological data our ?rst aim is to elucidate the interacting roles f context and content information in episodic memory. We further seek to identify the anatomical substrates of content and context information in the process of memory formation, retrieval and reinstatement (Aim 2). Finally, we will carry out parallel invasive (intracranial EEG) and non-invasive (scalp EEG) studies to assess the viability of decoding neural signatures of episodic memory using non-invasive methods. This work will serve as an important bridge between the behavioral and neurobiological approaches to human memory, and will provide insights into the mechanisms of memory decline both in normal aging and in neurological disease.

Public Health Relevance

One of the longstanding mysteries concerning human memory is how the brain is able to distinguish memories of nearly identical events that occurred at di?erent times. Cognitive theories of memory search and retrieval propose that each memory is laid down in its own unique temporal context, and that context information can be used to guide memory search. Our proposed research will combine computational modeling approaches with analysis of direct brain recordings in neurosurgical patients as well as non-invasive recordings in healthy adults to test these cognitive theories of memory and to identify the neural mechanisms underlying this vital human ability.

National Institute of Health (NIH)
National Institute of Mental Health (NIMH)
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Cognition and Perception Study Section (CP)
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Buhring, Bettina D
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University of Pennsylvania
Schools of Arts and Sciences
United States
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Kahana, Michael J; Aggarwal, Eash V; Phan, Tung D (2018) The variability puzzle in human memory. J Exp Psychol Learn Mem Cogn 44:1857-1863
Weidemann, Christoph T; Kahana, Michael J (2018) Dynamics of brain activity reveal a unitary recognition signal. J Exp Psychol Learn Mem Cogn :
Kuhn, Joel R; Lohnas, Lynn J; Kahana, Michael J (2018) A spacing account of negative recency in final free recall. J Exp Psychol Learn Mem Cogn 44:1180-1185
Healey, M Karl; Long, Nicole M; Kahana, Michael J (2018) Contiguity in episodic memory. Psychon Bull Rev :
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Solomon, E A; Kragel, J E; Sperling, M R et al. (2017) Widespread theta synchrony and high-frequency desynchronization underlies enhanced cognition. Nat Commun 8:1704
Long, Nicole M; Kahana, Michael J (2017) Modulation of task demands suggests that semantic processing interferes with the formation of episodic associations. J Exp Psychol Learn Mem Cogn 43:167-176

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