🧠 Brain Engine v3 — Closed-Loop Brain Architecture

21 brain components · 13-module ComponentBus · Cognitive LLM broadcast · 102 TDD tests

Brain Engine v3 is a biologically-plausible brain architecture implemented in Rust. Each component maps to a real brain region with a computational model grounded in peer-reviewed neuroscience papers. A ComponentBus broadcast system ensures bidirectional communication between all modules, and a cognitive LLM layer (via rig-core) serves as the global workspace — reading the bus, reasoning, and broadcasting decisions back to every component.

---

Architecture

3 rounds convergence → Cognitive(LLM) broadcast → 2 rounds post-convergence

ComponentBus (13 modules read/write the bus)
  ├── P0 Neuromodulators  (Doya 2002: TD meta-learning γ/β/α)
  ├── P1 Hippocampus      (McClelland 1995: CLS pattern separation)
  ├── P2 Basal Ganglia    (Bogacz 2006: drift diffusion SDE)
  ├── P2.5 Cerebellum     (Ito 2006: LTD sequence learning)
  ├── P3 DMN              (Buckner 2008: counterfactual thinking)
  ├── P4 Wave             (ACT-R: spreading activation + propagation)
  ├── P5 Thalamus         (Sherman 2005: dual-mode gating)
  ├── P6 Interoception    (Seth 2013: predictive coding)
  ├── Emotion             (Barrett 2017: constructed emotion)
  ├── Hormone             (Sapolsky 2015: allostatic load)
  ├── Attention           (Itti 2001: saliency + biased competition)
  ├── Reflex              (Sherrington 1906: spinal hierarchy)
  └── Predictive          (Friston 2010: hierarchical predictive coding)

Referenced Papers

Component	Paper	Core Math
P0	Doya (2002) Metalearning and neuromodulation	TD meta-learning: γ=0.3+5HT·0.6, β=1.0+NE·5.0
P2	Bogacz (2006) The physics of optimal decision making	Drift diffusion: dx = A·dt + c·dW
P1	McClelland (1995) Complementary Learning Systems	Sparse encoding + pattern separation
Emotion	Barrett (2017) The theory of constructed emotion	Core affect + concept construction
Predictive	Friston (2010) The free-energy principle	Hierarchical predictive coding + precision
Hormone	Sapolsky (2015) Stress and the brain	Allostatic load model
Attention	Itti & Koch (2001) Computational modelling of visual attention	Saliency map + biased competition
Habit	Daw et al. (2005) Uncertainty-based competition	Goal-directed ↔ Habitual control
Goal	Botvinick (2009) Hierarchical models of behavior	Hierarchical RL + gradient effect
Reflex	Sherrington (1906) The integrative action of the nervous system	Spinal reflex hierarchy
Reward	Schultz (1997) A neural substrate of prediction and reward	TD(λ) eligibility traces
P5	Sherman (2005) Thalamocortical loops	Driver/Modulator dual mode
P6	Seth (2013) Interoceptive inference	Predictive coding
P3	Buckner (2008) The brain's default network	Counterfactual + autobiographical recall

---

Quick Start

cd brain-engine-rs

# Run all 102 tests
cargo test

# Use as a library
use brain_engine::brain::BrainEngine;
use brain_engine::bus::ComponentBus;

let mut brain = BrainEngine::new(config);
let result = brain.bus_tick(&snapshot).await;

---

Project Structure

brain-engine-rs/
├── src/
│   ├── brain.rs          ← Orchestrator + convergence tick
│   ├── bus.rs            ← ComponentBus (13-module broadcast bus)
│   ├── llm.rs            ← Cognitive LLM layer (rig-core)
│   ├── types.rs          ← Core types
│   ├── modulator.rs      ← P0 Neuromodulators (Doya 2002)
│   ├── memory.rs         ← P1 Hippocampus (McClelland 1995)
│   ├── basal.rs          ← P2 Basal Ganglia (Bogacz 2006)
│   ├── cerebellum.rs     ← P2.5 Cerebellum (Ito 2006)
│   ├── dmn.rs            ← P3 DMN (Buckner 2008)
│   ├── wave.rs           ← P4 Wave (ACT-R)
│   ├── thalamus.rs       ← P5 Thalamus (Sherman 2005)
│   ├── interoception.rs  ← P6 Interoception (Seth 2013)
│   ├── emotion.rs        ← Emotion (Barrett 2017)
│   ├── hormone.rs        ← Hormone (Sapolsky 2015)
│   ├── attention.rs      ← Attention (Itti 2001)
│   ├── reflex.rs         ← Reflex (Sherrington 1906)
│   ├── predictive.rs     ← Predictive (Friston 2010)
│   ├── habit.rs          ← Habit (Daw 2005)
│   ├── goal.rs           ← Goal (Botvinick 2009)
│   ├── reward.rs         ← Reward (Schultz 1997)
│   ├── utils.rs
│   └── test_helpers.rs
├── Cargo.toml
└── RESEARCH.md

---

Status

Tests:   102 ✅ (all passing)
Build:   ✅ (0 errors, 1 intentional warning)
Modules: 21 brain components
Bus:     13/13 with bus_tick
Coverage: TDD-driven, every component has failing-test-first

---

Version History

• v1 (archive branch): OpenCode plugin — 20 LLM agents via task(), 149 tests
• v2 (archive branch): Standalone npm package — 20 parallel sessions, 550+ tests, signal competition + BG gating
• v3 (current): Rust rewrite — 21 native modules, ComponentBus closed-loop architecture, 102 TDD tests, paper-grounded

---

License

MIT