The brain gives us awareness of ourselves and of our environment, processing a constant stream of sensory information. Every creative idea, feeling, and the plan is developed by our brain. New UC Berkeley research into demonstrates that like swinging a tennis racket during a ball toss to serve an ace, slow and speedy brainwaves during deep sleep must sync up at precisely the correct moment to hit the save button on new memories.
While these brain rhythms, occurring several times each night, move in perfect lockstep in youthful adults, discoveries published in the journal Neuron demonstrate that, in old age, slow waves during non- rapid eye movement (NREM) sleep fail to make timely contact with speedy electrical bursts known as “spindles.”
Study senior author Matthew Walker, a UC Berkeley professor of neuroscience and psychology and director of the campus’s Center for Human Sleep Science said, “The mistiming prevents older people from having the ability to effectively hit the save button on new memories, prompting overnight forgetting as opposed to remembering”.
Walker added, “As the brain ages, it can’t correctly organize these two deep-sleep brain waves”. “Like a tennis player who is off their game, they’re swiping and missing.”
In tennis lingo, for example, the slow brainwaves or oscillations represent the ball toss while the spindles symbolize the swing of the racket as it intends to make contact the ball and serve an ace.
Study lead author Randolph Helfrich, a postdoctoral fellow in neuroscience at UC Berkeley said, “Timing is everything. In a very narrow opportunity time window (approximately one-tenth of a second), just when the slow waves and spindles come together, can the brain adequately put new memories into its long-term storage.”
In addition, scientists found that the aging brain’s failure to organize deep-sleep brainwaves is most likely because of degradation or atrophy of the medial frontal cortex, a key region of the brain’s lobe that generates the deep, restorative slumber that we enjoy in our childhood.
Walker said, “The worse the atrophy in this brain region of older adults, the more uncoordinated and inadequately timed are their deep sleep brainwaves. But, there is a silver lining: Sleep is currently new objective for potential therapeutic intervention”. To amplify slow waves and get them into the optimal match up with spindles, scientists intend to apply electrical brain stimulation to the frontal lobe in future experiments.
Walker said, “We hope to restore some degree of healthy deep rest in the elderly and those with dementia, by electrically boosting these nighttime brainwaves, and in doing as such, salvage parts of their learning and memory.”
For the examination, scientists compared the overnight memory of 20 healthy adults in their 20s to that of 32 healthy older adults, mostly in their 70s. Before going to bed for an entire night’s sleep, participants learned and were then tested on 120-word sets.
As they slept, scientists recorded their electrical brain wave activity utilizing scalp electroencephalography (EEG). The next morning, examine participants were tested again on the word pairs, this time while experiencing functional and structural magnetic resonance imaging (fMRI) scans.
The EEG outcomes demonstrated that in older individuals, the spindles consistently peaked early in the memory-consolidation cycle and missed syncing up with the slow waves. In addition, brain imaging demonstrated grey matter atrophy in the medial frontal cortex of older adults, which deterioration that crumbling within the frontal lobe keeps deep slow waves from perfectly matching up with spindles.