New discovery on memory consolidation
Some scientific discoveries surprise even the scientist that make them. A group of scientists from the MIT has challenged a basic assumption about memory encoding in the brain.
We use to think that memories are stored in the hippocampus for a short period and then, if consolidated, they pass onto the long-term storage in the neocortex. In this study, Kitamura and his team have demonstrated that memory consolidation works totally different. The memories are stored in both places, and as the neocortex memory matures overtime, the hippocampus memories gradually become silent. “It is immature or silent for the first several days after formation,” Prof Tonegawa said, referring to the memories stored in the cortex.
This consolidation process depends on afferents from both the hippocampus and the amygdala. The researchers also showed the long-term memory never matured if the connection between the hippocampus and the cortex was blocked.
This new finding is utterly surprising, and requires a rewriting of the textbooks on the causal mechanisms of memory. Practically speaking, this means that there can be traces of long-term learning even without the involvement of working memory. As some applied neuroscience companies suggest that a measure of working memory is the sole source of encoding and memory, this puts a dent in that claim. Rather, we should seek to understand, measure and affect these different and parallel systems of memory.
The study, published in Science, is a shift in memory encoding. Our CEO and PhD. Professor Thomas Ramsøy has received the news with great enthusiasm:
“If this holds up for humans — we don’t know yet — we may think that some things can be learned through two mechanisms. That said, we should remember that the memories shown here are not explicit, declarative memories, but rather basic, emotional memories. Not that this is less relevant, neither for humans in general or for consumer behaviours. But it suggests that the models we’ve used so far are more heterogeneous than we’ve known.
Turning this on its head, in time we may be able to understand and affect these memories differently. How cool would it be to test whether we could construct conflicting memories between short-term and long-term, which would create a dissociation in animal/human behaviour without having an odd feeling about it?
Curiously, when I was working the lab of now famous Moser couple and Nobel laureates in Trondheim, we ablated the hippocampus to see how it affected spatial learning. However, that deficiency seemed to discontinue after a few days post-surgery, and rats that were tested after a few days (no training in between) did better than those that were tested shortly after the ablation. I should probably reach out to the Mosers and ask them.”
Memory encoding is a widely used success index in branding and advertising, and understanding the mechanisms underlying such processes is crucial to measure and affect memory.
These findings provide unprecedented insights for human brain disease (such as Alzheimer’s disease) and have great potential applications in Consumer Neuroscience as well.