Researchers from Tel Aviv University and UCLA Health have made major advancements in their study of how the brain consolidates memories while we sleep. Their study, which was published in Nature Neuroscience, offers physiological evidence in favor of the prevailing theory of memory consolidation and raises the possibility that deep brain stimulation during sleep may improve memory.
The prevalent view states that during deep sleep, the cerebral cortex, which is linked to higher brain processes, and the hippocampus, which is responsible for memory, converse with one another. Memory consolidation is made easier at this stage by synchronized neural activity and slow brain waves. The team of researchers, led by Dr. Itzhak Fried, director of epilepsy surgery at UCLA Health, decided to further explore this study and look into deep brain stimulation’s potential for memory enhancement.
18 epileptic patients at UCLA Health who had electrodes implanted in their brains for seizure detection presented a unique opportunity for the research team. Two sessions of the research were held across two nights and mornings. Before going to bed, participants were given photos of animals and famous people, and their memory of the photos was examined both right away and afterward after a night of rest.
The participants in the second session were exposed to fresh pairings just before bedtime and received focused electrical stimulation all through the night. A closed-loop method was used to give this stimulation, synchronizing the electrical pulses with the subjects’ brain activity while they were deep asleep. They were again asked to remember the photos the next morning.
The final results appeared excellent. After a night of electrical stimulation in comparison to a night of undisturbed sleep, participants performed better on memory tests. Memory consolidation is suggested by electrophysiological markers that showed enhanced information flow between the cortex and the hippocampus. The process was compared by the researchers to improve the information highway in the brain to enable increased long-term memory storage.
Even though the study sheds light on memory consolidation and the possibility of deep brain stimulation, more investigation is required. However, the results provide individuals with cognitive impairments like Alzheimer’s disease hope. Future ground-breaking treatments may result from an improved understanding of how the brain functions when we sleep.
Numerous researchers from UCLA and Tel Aviv University participated in the project, which was co-supervised by Yuval Nir of Tel Aviv University. The work was funded by several research funds and charities, and the authors have indicated that they have no competing interests.