‘Pink noise’ boosts deep sleep, memory for older adults

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As we age, our quality of sleep de
clines. Researchers believe that
this may contribute to later-life memory loss. New research, however, suggests that there may be a simple solution to this problem: “pink noise.”
Researchers say that pink noise may help to improve deep sleep quality and memory for older adults.
Pink noise is defined as gentle, soothing sound whereby each octave possesses equal energy. In essence, pink noise is the background noise that we hear in everyday environments.
Researchers from Northwestern University in Evanston, IL, found that when they synced pink noise to the brain waves of older adults as they slept, the sound not only enhanced their quality of deep sleep, but it also improved their memory.
Senior author Dr. Phyllis Zee, professor of neurology at the Feinberg School of Medicine at Northwestern, and colleagues recently published their findings in the journal Frontiers in Human Neuroscience.
Numerous studies have highlighted the importance of sleep for memory consolidation – that is, the brain’s ability to convert short-term memories into long-term memories.
Slow-wave sleep (SWS) – more commonly referred to as deep sleep – is part of the non-rapid eye movement (NREM) sleep cycle that is considered important for memory consolidation. As we get older, however, the quality of SWS can decrease.
Studies have shown that disruptions to NREM sleep in older age can have negative consequences for memory.
According to Dr. Zee and team, previous research in young adults has uncovered a link between acoustic stimulation of slow-wave brain activity during sleep and improved memory. However, they note that studies using acoustic stimulation in older adults are lacking.
To address this gap in research, Dr. Zee and colleagues enrolled 13 older adults, aged between 60 and 84 years, to their study.
All adults were subject to one night of sham stimulation and one night of acoustic stimulation, which were around 1 week apart.
The acoustic stimulation incorporated pink noise that was synced to their brain waves as they slept.
For each session, the adults completed two memory recall tests – one before they went to sleep at night, and one after they woke up the following morning.
While memory recall improved under both conditions, the researchers found that the average improvement following acoustic stimulation was three times greater than with the sham stimulation.