Architectures
Memory Systems
STM, LTM, Episodic, and Semantic storage in AGI
Memory Systems
An AGI system cannot rely on a static weight matrix alone. It needs a dynamic, multi-layered memory system to store experiences, facts, and skills.
The Multi-Layer Memory Model
AGI memory is often modeled after human cognitive psychology, distinguishing between different durations and types of information.
1. Short-Term / Working Memory (STM)
The "scratchpad" of the mind. It stores information currently being processed.
- In AGI: Attention windows, current state buffers, or "Active Atoms" in the AtomSpace.
- Capacity: Limited but highly accessible.
2. Long-Term Memory (LTM)
Persistent storage of knowledge and experience.
| Type | Description | AGI Implementation |
|---|---|---|
| Episodic | Personal experiences (events) | Narrative databases, timeline logs |
| Semantic | Facts and concepts (Socrates is a man) | Knowledge Graphs, AtomSpace |
| Procedural | Skills and habits (how to drive) | Learned policies, MeTTa scripts |
Visualizing Memory Flow
graph TD
SensoryInput[Sensory Input] -->|Attention| WM[Working Memory]
WM -->|Encoding| LTM[Long-Term Memory]
LTM -->|Retrieval| WM
subgraph LTM Structure
Semantic[Semantic Memory: Facts]
Episodic[Episodic Memory: Events]
Procedural[Procedural Memory: Skills]
end
Encoding --> Semantic
Encoding --> Episodic
Encoding --> ProceduralForgetting and Consolidation
A crucial part of AGI memory is Active Selection. If a system remembers everything perfectly, it eventually becomes overwhelmed by noise.
- Consolidation: Moving important working memory items into LTM during "down-time" (similar to sleep).
- Graceful Forgetting: Lowering the Importance (STI/LTI) of rarely used Atoms until they are purged or archived.
Implementation in Hyperon
In the Hyperon framework, memory is unified in the AtomSpace.
- Every Atom has Attention Values (STI/LTI).
- This allows the system to treat memory as a dynamic, self-organizing graph rather than a static database.
Next: Reasoning Engines