The overall result of Karl Lashley's research seeking the engram of human memory was that he failed to find a specific, localized engram or memory trace. Lashley's experiments demonstrated that memory is not stored in a single area of the brain but rather is widely distributed across various cortical areas. He proposed two key principles from his findings:
- Equipotentiality: Any part of a cortical area could potentially support the memory function, suggesting that the function of lost neurons could be taken over by other neurons.
- Mass Action: The severity of memory impairment was related to the amount of brain tissue damaged, not the location, implying that many parts of the brain work together to support memory.
Lashley concluded that the engram is a distributed representation involving networks of neurons rather than a single localized site.
Subsequent research has built on his findings, showing different types of memory are supported by distinct brain areas and pathways, and modern techniques have identified neuronal networks that participate in memory encoding and retrieval, somewhat validating Lashley's fundamental concepts of distributed memory representation.
