'The memory web' has been untangled by a
new study by researchers from the Center for Systems Neuroscience
at the University of Leicester, in collaboration with the University of
California Los Angeles. Researchers have shed 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.
‘Internet search engines such as Google and Bing have been used for exploring a much larger database of associations between concepts and 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 Center 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 behavioral 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
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."