Episodic memory is defined as the type of explicit memory in which aspects of an event are integrated together and associated with the context in which they occur. Deficiency in episodic memory can be devastating to everyday functions, and is a symptom ubiquitous across many neurological disorders. Interestingly, patients with difficulty in episodic memory function may also exhibit difficulty segmenting continuous information into meaningful events. Recently it has been shown in healthy adults that episodic memory performance and event segmentation ability are not independent measures. An ongoing representation of context is critical for appropriate recognition of novelty and event segmentation has been shown to influence memory organization. In addition, event segmentation can induce top-down processes to modulate novelty responses and expectations. The purpose of this proposal is to understand event segmentation and its relationship to episodic memory. This will help to inform the dependencies between these processes in healthy adults and may also have implications for patients with neurological disorders who exhibit deficiencies in these functions. We will examine these processes using electrocorticography, functional magnetic resonance imaging and behavioral measures, motivated by predictions of a computational neural network model of episodic memory. We will characterize how event structure and segmentation impact brain activity while information is being presented and during subsequent memory retrieval, as well as how they impact which information is remembered and how that information is organized in memory.
The ability to process information in order to form new memories, as well as to associate the information with previous memories, is critical to our everyday lives, and impairments with these abilities are common symptoms of neurological disorders and healthy aging. This proposal examines how modulations in information processing can influence memory formation, organization and retrieval. Having a more complete picture of the dynamic nature of memory is necessary to pinpoint the deficiencies with memory functions that are symptomatic of neurological disorders and of healthy aging.
| Lohnas, Lynn J; Duncan, Katherine; Doyle, Werner K et al. (2018) Time-resolved neural reinstatement and pattern separation during memory decisions in human hippocampus. Proc Natl Acad Sci U S A 115:E7418-E7427 |
