Scientists acknowledge how complexly the brain functions in learning new things, recognizing and recollecting images and ideas that have been previously brought up. In this regard, they aim to better understand memory creation and loss to further seek methods of prevention with related diseases like Alzheimer's.
An international team of researchers collaborated to conduct a first among studies to observe learning and memory cell activities in the brain, by using celebrity photos.
The researchers from the University of California Los Angeles (UCLA) and University of Leicester in UK conducted an experiment to monitor brain activity in 14 participants and published their findings in the online journal Neuron.
The 14 participants, with sever epilepsy and who were hospitalized at UCLA, had electrodes attached to their brains for identifying seizure focus for possible surgical intervention and, especially for the study, observing neuron activity.
In the experiment, the researchers compared the activities of single brain cells from when new information was learned to when they were associated with previously captured information - or images.
First, they flashed images of people - celebrities - and took note of the nerve cells that fired up at the sight of, for example, Jennifer Aniston or Clint Eastwood.
Next, they flashed separate images of places or landmarks like the Leaning Tower of Pisa. The images of the places were then not related to the images of people. Nerve cells that fired up where also recorded.
They then combined the people and places into one related image, say, Clint Eastwood by the Leaning Tower of Pisa, and showed them to the participants. Again, they identified which single nerve cells fired up.
Finally, they took away the idea of a specific person in a specific place and again showed just the landmarks to the participants. Neuron activity was monitored; the scientists found that in the fourth cycle of flashing images when the participants had already seen both the people and places in related images, the sight of just a landmark also stimulated the nerve cells that initially fired up when the images of celebrities were shown.
"This study goes into the heart of the neural code underlying one of the most fundamental aspects of human cognition and memory, namely the formation of associations," said Dr. Itzhak Fried, the study's senior author and professor of neurosurgery and psychiatry and biobehavioral sciences at the Geffen School of Medicine at UCLA and the Semel Institute for Neuroscience and Human Behavior.
The researchers also point out a dramatic change that neurons could go from being silent to firing up rapidly at the exact moment of learning.
"The astonishing finding was that this basic code is so explicit at the level of individual neurons in the human brain," confirmed Fried.
Some scientists believe that solitary or only a few nerve cells represent a single concept or person. Others believe an entire host of neurons function as one to form a memory.
The study conducted by Fried's team aimed to test the two opposing theories and hope to further understand the very basics of learning and memory.
