ePoster

Functions of the medial temporal lobe in memory and navigation of conceptual spaces

Elias Rau, Nora Herweg, Rebekka Heinen, Nikolai Axmacher
FENS Forum 2024(2024)
Messe Wien Exhibition & Congress Center, Vienna, Austria

Conference

FENS Forum 2024

Messe Wien Exhibition & Congress Center, Vienna, Austria

Resources

Authors & Affiliations

Elias Rau, Nora Herweg, Rebekka Heinen, Nikolai Axmacher

Abstract

Abundant work has highlighted the functional role of the hippocampal formation in navigation behaviour across species. Recent studies highlight evidence that the same neural coding mechanisms found to underly the representation of physical spaces also apply to conceptual domains. Specifically, the representation of locations in both physical and conceptual spaces is reflected in distinct neural activity patterns in hippocampus and entorhinal cortex. Electrophysiological work from rodents has shown that single hippocampal place cells represent different locations in different spaces – a functional property termed “remapping”. Such remapping is believed to be essential for pattern separation and context-dependent memory and may depend on the (re-)alignment of grid cells in entorhinal cortex. In humans, evidence for remapping remains scarce. Here, we investigate whether and how neural representations of familiar concepts in medial temporal lobe are embedded into context-dependent conceptual spaces, ultimately shaping subsequent recognition memory. Participants rated pairwise distances of images of animal concepts on various conceptual dimensions while undergoing fMRI. Using behavioural distance metrics, we model subject-specific and global 2D spaces of concept relationships and relate rated and reconstructed distance estimates to neural representations and subsequent memory performance. We show that rated distances but also reconstructed distances in conceptual spaces during encoding promote memory performance during subsequent recognition. On the neural level, we combine representational similarity analysis with a searchlight approach to identify concept-specific and context-dependent representations during memory formation.

Unique ID: fens-24/functions-medial-temporal-lobe-memory-6d07ff38