New research clarifies how brain stores memories
Washington DC, US: A new hypothesis put forth by scientists at the HHMI Janelia Research Campus and associates at UCL contends that the importance of memory for potential futures reveals its location in the brain.
The theory provides a fresh perspective on systems consolidation, a process that moves some memories from the hippocampus, where they are initially stored, to the neocortex, where they are kept for a longer period of time.
The hippocampus and neocortex gradually transition from one another to the neocortex, according to the traditional theory of systems consolidation. However, research indicates that not all memories are transferred to the neocortex and instead remain in the hippocampus permanently.
No one has yet discovered mathematically what determines whether a memory stays in the hippocampus or whether it is consolidated in the neocortex, despite the recent psychological theories that were put forth to explain this more complex view of system consolidation.
In order to help solve this enduring issue, Janelia researchers are now putting forth a fresh, quantitative perspective on system consolidation. They are suggesting a mathematical neural network theory in which memories consolidate to the neocortex only if they enhance generalisation.
We can apply generalisations to other situations because they are built from the consistent and predictable elements of memories. The fact that canyons indicate the presence of water is one example of how we can generalise certain aspects of memories to better understand the outside world.
This is different from episodic memories -- detailed recollections of the past that have unique features, like an individual memory we have of hiking to a particular canyon and coming upon a body of water.
Under this view, consolidation doesn’t copy memories from one area of the brain to another but rather creates a new memory that is a generalization of previous memories. The amount that a memory can be generalized – not its age -- determines whether it is consolidated or remains in the hippocampus.
The researchers used neural networks to show how the amount of consolidation varies based on how much of a memory is generalizable. They were able to reproduce previous experimental patterns that couldn’t be explained by the classical view of systems consolidation.
The next step is to test the theory with experiments to see if it can predict how much a memory will be consolidated. Another important direction will be to test the authors’ models of how the brain might distinguish between predictable and unpredictable components of memories to regulate consolidation. Uncovering how memory works can help researchers better understand an integral part of cognition, potentially benefitting human health and artificial intelligence.
