Speaker
Description
We introduce a fully spiking, three-dimensional model of the hippocampus–neocortex loop that captures the complementary learning systems (CLS) functions [1] of rapid pattern separation, sequence completion and slow cortical consolidation. Dentate gyrus (DG), CA3 and CA1 are represented as spatially distinct 3-D liquid-state networks [2] whose connectivity mirrors hippocampal anatomy: extremely sparse feed-forward DG → CA3 projections support pattern separation, dense recurrent links within CA3 enable auto-completion, and plastic CA1 → cortex pathways transfer reactivated traces to long-term memory. Intrinsic θ–γ oscillations emerge from local inhibition and periodically trigger sharp-wave replay events. The model is embedded in a minimal T-maze task in which an agent’s position is encoded by place-cell activity and decoded by a basal-ganglia read-out that selects actions through deep learning. Preliminary simulations indicate that sparse DG input markedly enhances CA3 pattern separation, while replay-driven potentiation at CA1 → cortex synapses clearly improves post-sleep maze performance. Conversely, reducing DG sparsity, which is an analogue of early Alzheimer pathology, induces pronounced place-field overlap, increases recall errors and degrades spatial navigation. These results demonstrate that large-scale, 3-D spiking substrates can reproduce key hippocampal dynamics and their behavioural consequences, positioning NEST as a practical platform for studying memory consolidation, replay and disease-related degeneration in silico.
References
[1] McClelland J L, McNaughton B L, O'Reilly R C. Why there are complementary learning systems in the hippocampus and neocortex: insights from the successes and failures of connectionist models of learning and memory[J]. Psychological review, 1995, 102(3): 419.
[2] Maass W, Natschläger T, Markram H. Real-time computing without stable states: A new framework for neural computation based on perturbations[J]. Neural computation, 2002, 14(11): 2531-2560.
| Preferred form of presentation | Poster & advertising flash talk |
|---|---|
| Topic area | Simulator technology and performance |
| Keywords | Liquid state machine, Hippocampus, neocortex, complementary learning systems |
| Speaker time zone | UTC+9 |
| I agree to the copyright and license terms | Yes |
| I agree to the declaration of honor | Yes |
