# Category 12 — Cognitive Architectures

**Last updated: April 2026. All angle files cover April 2025–April 2026.**

This category covers how AI systems are structured to think — the architectural scaffolding around (or instead of) a raw LLM call. It spans four decades of classical symbolic architectures (Soar, ACT-R, CLARION, Sigma, OpenCog, LIDA), the LLM-era cluster of language agents (ReAct, Reflexion, Voyager, Generative Agents, MemGPT/Letta), Princeton's CoALA as the canonical bridge between them, and commercial instantiations from reasoning-first agent labs to game/NPC character engines to enterprise neuro-symbolic platforms. For the Unslop project, it answers the structural question: what must be around the LLM for its thinking and output to feel human across long horizons — typed memory, reflection loops, dual-process arbitration, persona grounding — rather than how each sentence should read.

## Angle Files

- [A-academic.md](A-academic.md) — Academic papers: CoALA (arXiv:2309.02427) as the canonical bridge, the Standard Model of the Mind (Laird/Lebiere/Rosenbloom 2017), classical architectures (Soar, ACT-R, CLARION, Sigma, LIDA), LLM+cog-arch hybrids (LLM-ACTR, NL2GenSym, CogRec, Structured Cognitive Loop, ACT-R hybrid personalization arXiv:2505.05083, Wray/Kirk/Laird cognitive design patterns arXiv:2505.07087), language-agent instantiations (ReAct, Reflexion, Tree of Thoughts, Voyager, Generative Agents, MemGPT), LLMs as cognitive models (Binz & Schulz, ICLR 2024), dual-process LLM work (Dualformer, ACPO, Reasoning on a Spectrum), graph memory surveys (arXiv:2512.13564 "Memory in the Age of AI Agents", Mem0 ECAI 2025, MAGMA Jan 2026, arXiv:2602.05665 graph-memory taxonomy), and metacognition papers (SOFAI npj AI 2025, ICML 2025 "Truly Self-Improving Agents", arXiv:2508.17959 "Language Models + Metacognition").
- [B-industry.md](B-industry.md) — Industry blogs and essays: Stanford HAI on believable agents, LangChain on reflection and CoALA-based production memory, Letta on context engineering and sleep-time compute (now with Letta Code and Letta Code App, Apr 2026), Sakana's Continuous Thought Machines, Jeff Hawkins/Numenta on sensorimotor grounding and Thousand Brains, Gary Marcus on world models and neurosymbolic vindication, Anthropic on context engineering, Voicebot/Kinsella on cognitive vs affective trust, John Laird on the cognitive-architecture hypothesis, Mem0 "State of AI Agent Memory 2026", SOFAI (npj AI 2025), Hume EVI 3/4 and Hume+Anthropic joint emotionally intelligent voice post.
- [C-opensource.md](C-opensource.md) — GitHub repositories: classical architectures (SoarGroup/Soar 416★, pyactr 179★, Hyperon v0.2.10 Feb 2026, AtomSpace 962★), believable-agent simulacra (generative_agents 21.1K★, StanfordHCI/genagents), stateful-memory agents (letta-ai/letta with Letta Code/Conversations API/Apr 2026 app, MineDojo/Voyager 6.8K★, simular-ai/Agent-S with Agent-S3 72.60% OSWorld), multi-agent societies (AutoGPT 183.5K★, MetaGPT 66.7K★, ChatDev 2.0 DevAll Jan 2026, CAMEL, AutoGen→Microsoft Agent Framework), dedicated memory-layer repos (mem0ai/mem0 ~48K★, MAGMA, DEEP-PolyU/Awesome-GraphMemory, Shichun-Liu/Agent-Memory-Paper-List), and theory scaffolding (ysymyth/awesome-language-agents, VoltAgent/awesome-ai-agent-papers 2026).
- [D-commercial.md](D-commercial.md) — Commercial landscape: reasoning-first labs (Imbue, Cognition/Devin 2.2, Reflection AI $2B Series B, xAI Grok 4.20 multi-agent, Anthropic adaptive thinking Claude Opus 4.7), post-transformer substrate bets (Symbolica, Extropic, AMI Labs/LeCun JEPA $1.03B seed Mar 2026), emotion-first platforms (Hume EVI 3 May 2025 + EVI 4-mini Jan 2026 + $50M Series B + Anthropic collaboration, Inflection Pi, Replika, Soul Machines Digital Brain), game/NPC engines (Inworld pivoted to Agent Runtime + voice AI with GDC 2025 production deployments, Convai), and enterprise neuro-symbolic orchestration (AI21 Maestro, OneReach, Adverant, Growth Protocol, Kortexya).
- [E-practical.md](E-practical.md) — Practitioner forums and how-tos: r/LocalLLaMA memory implementation threads (now including graph vs. vector discussion), Mem0 "State of AI Agent Memory 2026" benchmark, LessWrong architecture essays (janus on Simulators, Seth Herd on LMCAs, Leventov on exemplary actors), HN Show HN projects (Cogency, Mnemo Bayesian memory, DeltaMemory), structured metacognition papers (Think², MIRROR, "Language Models + Metacognition" Aug 2025, ICML 2025 "Truly Self-Improving Agents"), SOFAI-LM metacognitive arbitrator, TMLR 2025 "Stop Overthinking" survey, context-engineering practitioner consensus, and r/OpenAI/r/SEO writing-craft humanization canon.

## Synthesis and Legacy Summary

- [SYNTHESIS.md](SYNTHESIS.md) — The distilled synthesis across all five angles.
- [INDEX.md](INDEX.md) — Legacy category summary — superseded by SYNTHESIS.md, preserved for traceability.
