A model of how hierarchical representations constructed in the hippocampus are used to navigate through space
Bibliographic record
Abstract
Animals can navigate through complex environments with amazing flexibility and efficiency: they forage over large areas, quickly learning rewarding behavior and changing their plans when necessary. Some insights into the neural mechanisms supporting this ability can be found in the hippocampus (HPC)—a brain structure involved in navigation, learning, and memory. Neuronal activity in the HPC provides a hierarchical representation of space, representing an environment at multiple scales. In addition, it has been observed that when memory-consolidation processes in the HPC are inactivated, animals can still plan and navigate in a familiar environment but not in new environments. Findings like these suggest three useful principles: spatial learning is hierarchical, learning a hierarchical world-model is intrinsically valuable, and action planning occurs as a downstream process separate from learning. Here, we demonstrate computationally how an agent could learn hierarchical models of an environment using off-line replay of trajectories through that environment and show empirically that this allows computationally efficient planning to reach arbitrary goals within a reinforcement learning setting. Using the computational model to simulate hippocampal damage reproduces navigation behaviors observed in rodents with hippocampal inactivation. The approach presented here might help to clarify different interpretations of some spatial navigation studies in rodents and present some implications for future studies of both machine and biological intelligence.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".