Hebb’s theory of neural connections has had major implications for how neuroscientists and psychologists understand memory. One example is Long-Term Potentiation (LTP), a theory that emerged in the late 1960s showing that synapses are strengthened by recent patterns of activity, therefore confirming the findings of Hebbian Learning. 4 LTP is still a heavily researched topic today, with some exciting developments in the areas of dementia, Alzheimer’s disease and addiction treatment.
When it was first introduced, Hebbian Learning was seen as one part of the puzzle that surrounded memory function and storage. Around the 1950’s, however, researchers grew certain that neural networks were responsible for storing and retrieving associations, which opened up a whole new area of neuroscientific discovery. Combined with Lashley’s findings in his memory localization experiments, it was starting to become clearer that human beings possess different types of memories, and that each one is located in a different part of the brain.
These hypotheses were confirmed by the fascinating case of Henry Molson – who was, and still is, famously referred to as HM. HM suffered from epilepsy, and in 1953, his surgeon recommended that he have the medial temporal lobes of his brain removed. The surgery was successful in curing his epilepsy, but it appeared to severely damage his explicit, long-term memory recall (ie. his memory for factual information). HM could easily deploy his short-term memory, and had no trouble acquiring new motor skills or using what psychologists call his ‘implicit’ long-term memory (ie. ability to complete procedural tasks like riding a bike). HM wasn’t able to recall, however, that he had ridden a bike the day before since this was a “fact.” As a result of HM’s experience, medial temporal lobes are considered responsible for the formation of long-term explicit memories. Hebb’s theory was used to support this approach to the study of memory, since the idea that memories are formed and stored through neural connections was supported by the case of HM.
More recent studies have looked at how neural connections can be strengthened, and therefore how learning can be enhanced. Indeed, many advancements in neuroplasticity and associative memory research can trace links back to Hebbian Learning.
Hebbian Learning is also the basis for several advances in computer science, especially artificial intelligence.