While we've figured out many aspects of human life through scientific endeavour, one of the most fascinating is still one shrouded in mystery: how does human memory work? How do we create unforgettable episodes of time in our mind, which we are reminded of at certain locations or with certain people?
In a study published Wednesday in Neuron, researchers from the University of Leicester and UCLA in America have found new insights and answers to this question, with the helpful support of Clint Eastwood, Tiger Woods and Jennifer Aniston (I'll explain).
The teams showed people pictures of a variety of things, including family members and celebrities at different locations, to track how their brain activity changed with each one. This was to prove the hypothesis that they called the 'Jennifer Aniston neuron,' in which one neuron fires for a single image to form a concept surrounding that, hence making memories. They began to see a pattern as neurons that were initially responding to a specific person began to react to a specific location to, showing a link between the two in his/her memory and proving their theory to be true.
“The remarkable result was that the neurons changed their firing properties at the exact moment the subjects formed the new memories - the neuron initially firing to Jennifer Aniston started firing to the Eiffel Tower at the time the subject started remembering this association,” said Rodrigo Quian Quiroga, head of the Centre for Systems Neuroscience at the University of Leicester.
The study was done with 14 patients who have epilepsy. This is because they already had electrodes planted in their brains that were used to identify the focus of their seizures, meaning researchers could repurpose them and record the activity of single neurons.
The study suggest that brain activity in the medial temporal lobe, the brain's main engine for memory formation, changes as both person and location are linked. Taking the Jennifer Aniston example in Rodrigo's quote, separate images were shown of Jen and the Eiffel Tower, and neurons fired only to the actor. However once she was photoshopped into the photo of the landmark, the subject's neurons fired in a different response to both Jen and the Eiffel Tower, creating a new link.
"This is a radical departure from previous experiments in animals where changes have been observed mainly after long training sessions. This is critical to understanding the neural processes underlying real-life memory formation, as in real life we are not repeatedly exposed to an event in order to remember it - just one exposure is enough.” Rodrigo continued.
This is particularly telling as it shows memories can be formed in real-life after just one event. This kind of research doesn't just show an amazing discovery in neuroscience, it could have clinical applications, potentially around what deficits in this area can be seen in people with certain conditions like Alzheimer's.