HippBoundariesPE · Identifying the building blocks of episodic memory: how the hippocampus parses boundless experience into discrete events
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2016-08-18 → 2018-08-17
- EU contribution
- €183,455
- Participants
- 2
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
Identifying the building blocks of episodic memory: how the hippocampus parses boundless experience into discrete events
As we go about our lives, we experience a continuous stream of information. Yet when thinking about the past, we remember it as discrete events – ‘I attended a meeting’; ‘I went to see a movie’. How is our continuous experience transformed into these separate memories? Research has shown that people naturally segment experience into events, with relatively high agreement between them as to when transitions between events (event boundaries) occur. The current project is aimed at revealing how event boundaries affect the memory systems in our brain in charge of encoding new memories. An intriguing hypothesis, which we set out to test, is that event boundaries trigger activity in brain regions in charge of memory encoding. We found that event boundaries indeed trigger a strong response in the hippocampus, a key region involved in encoding of new episodes, and that the response was stronger for more salient boundaries. Moreover, the hippocampus responded primarily during these boundaries, and relatively little at other points in time. Together, this suggests that during continuous experience, event boundaries may trigger encoding activity that wraps up the preceding event as a cohesive unit, separating it from the next event. This project is part of a global objective to understand how we form memories for entire events. Memory research has traditionally focused on how the brain encodes memories for simple items, such as words, or pictures. By expanding our knowledge to uncover how the brain encodes whole episodes, which are much more similar to our real-life experience, we are laying the foundations for a better understanding of memory disorders.
Data: CORDIS, © European Union
Project objective
Life provides us with a continuous stream of information that ends up being organized in long-term memory as distinct events. How does this occur? Leading theories posit that surprising occurrences (when prediction of the immediate future fails) are interpreted by the system as event boundaries that segment ongoing experience. Will any type of surprise induce such segmentation? Moreover, how are these segments then laid down in memory as discrete units? The proposed research addresses these key issues in a two phase study, combining fMRI of healthy individuals with a neuropsychological study of amnesic patients, and using tailored film clips designed to dissociate between distinct forms of prediction error (PE) – low-level PE (salient perceptual changes) and high-level PE (explicit expectancy of an upcoming change). We hypothesize that the key region in this process may be the hippocampus, a region strongly linked to formation of episodic memory. Combining a 7T fMRI study (enabling distinction between hippocampal subfields) with a study of patients with focal hippocampal lesions will enable us to elucidate the nature and necessity of hippocampal involvement in segmentation. The significance of this study lays first in its potential to illuminate how real-life events are registered to memory, a process which is likely to differ significantly from the encoding of brief, simple stimuli that have been employed previously. The importance of studying encoding of complex events has recently received increasing recognition, yet this is still only at its infancy, with very few studies employing this approach. Combining the complementary expertise of the researcher and the host, the proposed research aims to identify what constitutes an event boundary in mnemonic processing. Through future collaborations, this has the potential to lead to applicable interventions for improving normal memory and ameliorating mnemonic disorders.
Original text from CORDIS.
Participants
- THE CHANCELLOR MASTERS AND SCHOLARS OF THE UNIVERSITY OF CAMBRIDGE · CAMBRIDGECoordinatorUnited Kingdom
- UNITED KINGDOM RESEARCH AND INNOVATION · SWINDONUnited Kingdom
Links
Data: CORDIS, © European Union