Spaces and sequences in the hippocampus: a homological perspective

Area of Science:

• Neuroscience
• Computational Neuroscience
• Cognitive Science

Background:

• Topological techniques, like simplicial homology, are increasingly used to analyze information flow in neural networks.
• Studies suggest cognitive functions rely on serial patterns of neural activity.

Purpose of the Study:

• To investigate serial patterns of neural activity in the hippocampus using path homology theory.
• To quantify the ordinal arrangement of hippocampal activity and compare it with topological analyses.

Main Methods:

• Application of path homology theory to analyze sequences of neural activity.
• Quantification of the ordinal arrangement of neuronal firing patterns during spatial navigation.
• Comparison of ordinal activity structures with previously studied topological structures.

Main Results:

• The vast majority of spatial navigation sequences are structurally equivalent.
• A stable ordinal schema of serial activity emerges from a few distinct sequence classes.
• Short activity motifs form the basis of both ordinal and topological structures.
• Ordinal organization stabilizes on timescales relevant to spatial learning.

Conclusions:

• Path homology provides a universal approach to studying neural sequences without prior assumptions.
• Hippocampal activity during spatial navigation exhibits a dominant ordinal organization based on short motifs.
• Ordinal and topological analyses capture complementary aspects of neural information processing.