Summary: A new study helps to untangle the memory web by shedding light on how neurons in areas of the brain associated with memory provide long term coding of associations between concepts.
Source: University of Leicester.
University of Leicester research in collaboration with the University of California Los Angeles uses internet searches to show how long-term memories are coded in the brain.
A new study by researchers from the Centre for Systems Neuroscience at the University of Leicester, in collaboration with the University of California Los Angeles, has helped to untangle ‘the memory web’ by shedding light on how neurons in memory-related areas provide a long-term coding of associations between concepts.
The team also used internet search engines such as Google and Bing for exploring a much larger database of associations between concepts and then explored more comprehensively how neurons represent the intricate web of associations and memories.
The research, which is published in the journal Nature Communications, shows that these neurons fire to relatively few concepts, which tend to be largely related.
Senior author Professor Rodrigo Quian Quiroga from the Centre for Systems Neuroscience at the University of Leicester explained: “We have previously proposed that these neurons — the ‘Jennifer Aniston’ neurons — are the building blocks of memory.
“They represent concepts and the links between them. In fact, these concepts and their associations are the skeleton of the memories we store. In line with this view, we tend to remember concepts and forget countless number of details. Not surprisingly, such details are not even encoded by these neurons.”
First author Emanuela De Falco, who is currently finishing her PhD at the University of Leicester, added: “I am really glad I had the chance to do my PhD in such a fascinating area of research, having the opportunity to record directly from neurons of patients and integrating results obtained with these neural recordings with behavioural and web-based results. 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.”
The team showed sets of pictures — about 100 per experiment — to patients implanted with clinical electrodes for clinical reasons, which allowed them to study how dozens of simultaneously recorded neurons in awake and behaving human subjects responded to the presented pictures.
The team then asked subjects how much they related a subset — about 10-20 — of these pictures with each other and defined a degree of association for all the pictures presented based on internet searches.
They found that whenever neurons fire to more than one concept, these tend to be related both according to the subjects’ scores and the internet searches.
Professor Quiroga added: “Interestingly, the patients were not performing a memory task, they were just passively watching pictures. So, the coding of associations is not contingent to the performance of a task – in which case, it could be argued that neurons temporarily encode such associations and then do something else – but it rather represents a long-term memory storage.”
The study, ‘Long-term coding of personal and universal associations underlying the memory web in the human brain’, which also involved Matias Ison at Leicester and Itzhak Fried at UCLA was funded by the Human Frontiers Science Programme and is published in the journal Nature Communications.
Funding: This work is supported by tThe Human Frontier Science Program Organization, Switzerland, Australia, India.
Source: Rodrigo Quian Quiroga – University of Leicester
Image Source: This NeuroscienceNews.com image is credited to University of Leicester.
Original Research: Full open access research for “Long-term coding of personal and universal associations underlying the memory web in the human brain” by Emanuela De Falco, Matias J. Ison, Itzhak Fried &and Rodrigo Quian Quiroga in Nature Communications. Published online November 15 2016 doi:10.1038/ncomms13408
[cbtabs][cbtab title=”MLA”]University of Leicester. “What Can Google Tell Us About ‘the Memory Web’ in the Brain?.” NeuroscienceNews. NeuroscienceNews, 15 November 2016.
<https://neurosciencenews.com/web-memory-neuroscience-google-5516/>.[/cbtab][cbtab title=”APA”]University of Leicester. (2016, November 15). What Can Google Tell Us About ‘the Memory Web’ in the Brain?. NeuroscienceNews. Retrieved November 15, 2016 from https://neurosciencenews.com/web-memory-neuroscience-google-5516/[/cbtab][cbtab title=”Chicago”]University of Leicester. “What Can Google Tell Us About ‘the Memory Web’ in the Brain?.” https://neurosciencenews.com/web-memory-neuroscience-google-5516/ (accessed November 15, 2016).[/cbtab][/cbtabs]
Abstract
Long-term coding of personal and universal associations underlying the memory web in the human brain
Neurons in the medial temporal lobe (MTL), a critical area for declarative memory, have been shown to change their tuning in associative learning tasks. Yet, it is unclear how durable these neuronal representations are and if they outlast the execution of the task. To address this issue, we studied the responses of MTL neurons in neurosurgical patients to known concepts (people and places). Using association scores provided by the patients and a web-based metric, here we show that whenever MTL neurons respond to more than one concept, these concepts are typically related. Furthermore, the degree of association between concepts could be successfully predicted based on the neurons’ response patterns. These results provide evidence for a long-term involvement of MTL neurons in the representation of durable associations, a hallmark of human declarative memory.
“Long-term coding of personal and universal associations underlying the memory web in the human brain” by Emanuela De Falco, Matias J. Ison, Itzhak Fried &and Rodrigo Quian Quiroga in Nature Communications. Published online November 15 2016 doi:10.1038/ncomms13408
