Researchers at Northwestern University found that gentle sound simulation with pink noise can boost deep sleep and could be used as a therapy for mild cognitive impairment.
Pink noise is similar to white noise but is deeper during slow waves. During the sound simulation with short pulses of pink noise during deep sleep, the participants’ brain activity showed that there was a significant relationship between the enhancement of deep sleep by sound, and memory.
Analysing the significance of pink noise
Participants undertook memory testing the night before and again in the morning. The researchers compared the differences in slow wave sleep with the pink noise sound simulation and without sounds, to assess the change in memory across both nights for each participant. Thy found that the individuals who had a twenty percent or more increase in slow wave activity recalled about more words in the memory test the next morning.
The importance of deep sleep for memory
According to the researchers:
- Mild cognitive impairment is often a precursor to Alzheimer’s disease;
- The greater the deep sleep enhancement, the better the memory response;
- Deep sleep is critical for memory consolidation; and
- Improving deep sleep eventually could be a viable therapy in people with mild cognitive impairment.
Dr Roneil Malkani, assistant professor of neurology at Northwestern University Feinberg School of Medicine and a Northwestern Medicine sleep medicine physician, explained: “Our findings suggest slow-wave or deep sleep is a viable and potentially important therapeutic target in people with mild cognitive impairment. The results deepen our understanding of the importance of sleep in memory, even when there is memory loss.”
The potential applications for mild cognitive impairment and Alzheimer’s
“There is a great need to identify new targets for treatment of mild cognitive impairment and Alzheimer’s disease,” Malkani added. “These results suggest that improving sleep is a promising novel approach to stave off dementia.”