Scientists Discover ‘Beautiful’ Secret of How Memories are Made
Scientists have uncovered that the brain makes two copies of every event
They were surprised to find the brain makes two copies of every event – one for the present and the other for the long-term.
Experts say the findings from the Riken-MIT Centre for Neural Circuit Genetics in the US along with a team from Japan were “beautiful and convincing.”
Two parts of the brain are involved in collecting and storing personal experiences.
Short-term memories are collected by the hippocampus while the cortex retains long-term memories.
Dr Amy Milton, who is a memory researcher at Cambridge University, said the study was “beautiful, elegant and extremely impressive”.
She added: “I’m quite surprised.
“The idea you need the cortex for memories I’m comfortable with, but the fact it’s so early is a surprise.
“This is one study, but I think they’ve got a strong case, I think it’s convincing and I think this will tell us about how memories are stored in humans as well.”
The discovery was first made back in the 1950s after the case of Henry Molaison whose hippocampus was damaged due to epilepsy surgery.
He struggled to make new memories but the ones before the operation remained intact.
It led experts to realise memories must be formed in the hippocampus and then moved to the cortex where they are “banked.”
New experiments carried out on mice at the US have come up with a different theory after watching the way memories were formed as brain cells responded to shock.
Light beamed into the brain helped to switch memories on and off by controlling neutrons.
Memories were found to be formed simultaneously in the hippocampus and the cortex.
Researchers found the cortex’s long-term memory did not kick in after memories were formed as it was “immature or silent.”
Scientists turned off the short-term memory and the shock event was forgotten.
The mice were forced to remember by manually switching the long-term memory on.
Professor Susumu Tonegawa, the director of the research centre, said: “This is contrary to the popular hypothesis that has been held for decades.
“This is a significant advance compared to previous knowledge, it’s a big shift.”
He described the discovery as “surprising.”
Mr Tonegawa said previous studies involving mice with Alzheimer’s showed memories were still being formed but were unable to retrieve them.
“Understanding how this happens may be relevant in brain disease patients,” he added.