Structure and variability in mnemonic representations
While the nature of representations in sensory cortex is relatively well characterized, our understanding of complex memory representations is less clear. For episodic memories, retrieval entails some partial reinstatement of signatures linked to initial event processing, which is itself influenced by factors like attention and prior knowledge. I will discuss how the hippocampus is involved in the encoding and retrieval of distributed traces, as well as how this structure might disambiguate cortical inputs in the service of precise memory. This work also shows that examining the structure of relationships between items in a set can provide insight into perceptual and conceptual aspects of memory. Given that prior knowledge can profoundly shape how information is processed and remembered, I will also present data on the reconfiguration of knowledge-based representational structures in subject matter experts (birdwatchers), and corresponding implications for episodic memory and new learning.