Memories helping us understand world get stored long-term, new research proposes

How useful a memory is in helping us understand the world determines where in our brain it resides, according to new research aiming to provide a better explanation of memory storage in the brain.

Under the classical view of systems consolidation, over time, all memories are known to move from their initial storage location of the hippocampus to the neocortex.

However, research has shown that certain memories continue to reside in the hippocampus despite passage of time.

This research from Howard Hughes Medical Institute, US, in collaboration with the University College, London, UK, puts forward a mathematical neural network theory, according to which a memory consolidates to the neocortex, the permanent residence, only if it improves generalisation. It is published in the journal Nature Neuroscience.

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Generalisation is constructed from the reliable and predictable aspects of memory that enable us to apply them to other situations and help us make sense of the world. For example, a canyon is seen to predict the presence of water.

This is different from episodic memories, which are detailed recollections of the past having unique features, such as an individual memory of hiking to a particular canyon and stumbling upon a body of water.

Under this theory, consolidation involves creating a new memory generalised from previous memories, rather than just copying memories from one part of the brain to another.

How much material that memory provides for generalisation determines if it gets to be consolidated or continues to stay in the hippocampus, and not its age, the study found using neural networks.

Following up this theoretical proposition with experimental studies is the next step for this research, including testing the authors' models of how the brain might distinguish between predictable and unpredictable aspects of memories while regulating consolidation.

Understanding how memory, including its storage, works is integral to comprehending cognition, with potential importance in human mental health and artificial intelligence.