Our daily experience is continuous, but when we later recall it, we often think about it in terms of discrete events: preparing a cup of coffee, a bike ride in the park, or a conversation with a friend. These remembered events are called episodic memories and are central to how we learn, plan for the future and maintain a sense of self. We know which areas of the brain support the formation and retrieval of such memories, with a key role being played by the hippocampus – a deep brain structure resembling a seahorse in shape (thus earning it its name). Yet we still do not know what is actually being stored as part of the memory. When we encode a memory, for example, of preparing coffee, do we store each element as a separate memory (grinding coffee, pouring water), or do we accumulate information about the entire event and then store a memory of the event as a whole? If we do store events, how does the brain decide when one event is over and a new one has begun? The MEME focuses on three aspects of how memories are stored:
1. At which points in time do people segment continuous experience into discrete events?
2. When are episodic memories stored – are they stored as individual elements or as integrated events?
3. How are events that unfold over time represented in the brain, with a specific focus on the hippocampus?
To address these questions, the project combines behavioural studies, brain imaging using functional MRI, and direct recordings from the hippocampus. These studies all employ unique, tailored videos (created using the ‘Sims’ life simulation game and AI) that are designed to be rich and complex, like naturalistic experience, yet at the same time allow subtle and precise manipulations to address the questions at hand.
Our long-term goal is to identify the “building blocks” of memory for events, understanding how the brain turns the continuous flow of experience into the episodes that shape our lives.
