The idea that the brain improves memory when you sleep has been supported by research from UCLA Health and Tel Aviv University.
In the research, epilepsy patients had targeted deep brain stimulation, which improved memory consolidation. These discoveries could be useful in memory problem treatments.
The primary idea of how human memory is strengthened when we sleep has also been supported by the first direct data reported by researchers.
Although it is well recognized that sleep is essential for improving memory, researchers are still striving to understand exactly how this process occurs in the brain at night.
The study team also discovered that focused deep brain stimulation during a crucial phase of sleep appeared to enhance memory consolidation.
The study, which was co-authored by Itzhak Fried, MD, Ph.D., and was published in the journal Nature Neuroscience, may provide fresh information on how deep-brain stimulation during sleep may one day benefit patients with memory problems like Alzheimer’s disease.
An innovative “closed-loop” technique that accurately matched electrical pulses in one brain area to brain activity recorded from another region was used to achieve this.
The cerebral cortex, which is linked to higher brain processes like thinking and planning, and the hippocampus, the brain’s memory center, communicate throughout the night, according to the leading hypothesis for how the brain turns new information into long term memories while you sleep.
This occurs at a period of profound sleep when brain waves are exceedingly slow and neurons in various brain regions alternate between firing swiftly and silently.
“This provides the first major evidence down to the level of single neurons that there is indeed this mechanism of interaction between the memory hub and the entire cortex. It has both scientific value in terms of understanding how memory works in humans and using that knowledge to really boost memory,” Fried stated.
The brains of 18 epilepsy patients at UCLA Health provided a unique chance for the researchers to test this idea using electrodes.
The electrodes were inserted into the patients’ brains to assist in determining the cause of their seizures throughout hospital stays, which normally last 10 days.
The investigation took place over two mornings and nights. Before going to bed, research participants were shown photographs of 25 famous people, including instantly recognizable figures like Marilyn Monroe and Jack Nicholson.
They were tested right away to see if they could remember which celebrity was associated with which animal, and they were checked once more the next morning following a nice night’s sleep.
On another night, they watched 25 brand-new celebrity-animal pairs before sleep.
This time, they had focused electrical stimulation overnight, and the next morning, their capacity to remember the pairings was evaluated.
Fried compared the real time closed loop system the researchers developed to this musical conductor in order to offer this electrical stimulation: When patients entered deep sleep, which is associated with memory consolidation, the device “listened” to the brain’s electrical impulses and gave mild electrical pulses instructing the quickly firing neurons to “play” in sync.
After a night of sleep with the electrical stimulation as opposed to a night of undisturbed sleep, each subject examined performed better on memory tests.
Important electrophysiological indicators also showed that information was moving between the hippocampus and the whole cortex, offering concrete proof that memory consolidation was taking place.
Fried mentioned that “We found we basically enhanced this highway by which information flows to more permanent storage places in the brain.”
Fried’s 2012 study published in the New England Journal of Medicine was the first to demonstrate the benefits of electrical stimulation for one’s memory.
Since then, his research into the potential benefits of deep brain stimulation for memory has continued, and it’s now focusing on the crucial period of sleep.
He has now won a $7 million NIH grant to investigate whether AI can support the identification and reinforcement of certain memories in the brain.
“In our new study, we showed we can enhance memory in general. Our next challenge is whether we have the ability to modulate specific memories,” the expert shared.