A new study could have just figured out how the brain codes long-term memories. Researchers from the Center for Systems Neuroscience at the University of Leicester, in tandem with the University of California Los Angeles (UCLA) attempted to untangle “the memory web” by showing how neurons, specifically in the medial temporal lobe (MTL), produce long-term coding of associations between concepts.
“We have previously proposed that these neurons — the ‘Jennifer Aniston’ neurons — are the building blocks of memory,” said senior author Rodrigo Quian Quiroga from the University of Leicester’s Centre for Systems Neuroscience. “They represent concepts and the links between them.”
The study,published in Nature Communications, revealed that MTL neurons fire to concepts that are largely related. In other words, the same neuron fires whenever the brain reacts to things that have strong levels of association. The researchers used search engines like Google and Bing to explore a larger database of associations.
The researchers conducted experiments with patients that have electrode implants, due to clinical reasons. They showed sets of pictures of about a hundred per patient. The subjects were then asked to relate a subset of 10-20 images with each other, with the degrees of association defined based on internet searches.
“I found it incredibly interesting to see how, after thousands of web searches, the web metric was actually able to tell us something about the neurons we recorded,” said Emanuela de Falco, first author.
They saw that neurons fire to more than one concept when these are related, according to both the internet searches and the subject’s scores. The study shows how the brain is able to retain concepts more, despite forgetting countless details.
This gives a very valuable insight into how the brain works, specifically with long-term memory and association, and can therefore be valuable in Alzheimer’s research. It is also an important step in being able to reprogram the human brain in the future. Before we are able to manipulate the brain in beneficial ways, we must first gain mastery over the understanding of how it naturally works.