Episodic Semantic Memory Jun 2026

By recognizing how our brains separate from knowledge , we gain a deeper appreciation for the complex machinery that makes us who we are.

| Disorder | Episodic | Semantic | Hybrid deficit | |----------|----------|----------|----------------| | (svPPA) | Preserved (can recall personal events) | Severely impaired | Cannot use general knowledge to structure episodic recall – stories become disjointed. | | Alzheimer’s disease | Impaired early | Impaired later | Lose both, but semantic facts (e.g., names of objects) often degrade later than recent episodes. | | Developmental amnesia (hippocampal) | Impaired | Intact or mildly impaired | Can learn facts (semantic) but cannot recall where/when they learned them. | | Post-traumatic stress disorder | Intrusive, over-specific | Normal | Traumatic episode dominates, over-general semanticization of safety cues fails. | episodic semantic memory

Decades later, Tulving revised his theory to incorporate brain evolution. This is the paper that introduced the SPI (Serial-Parallel-Independent) model, explaining how semantic memory might "evolve out of" episodic memory. By recognizing how our brains separate from knowledge