MIT scientists boost the brain’s natural “cleaning” process during sleep using pink noise
Researchers at the Massachusetts Institute of Technology have found that precisely timed bursts of pink noise during sleep can increase the movement of cerebrospinal fluid, which plays a role in the brain’s natural process of clearing metabolic waste.
Unlike white noise, pink noise contains more energy at lower frequencies and can resemble steady rainfall or a distant waterfall. In the experiment, however, the sound was not played continuously. Researchers delivered 50-millisecond bursts at specific points during the brain’s slow-wave activity.
Pink noise increased fluid waves in the brain
The study involved 14 healthy volunteers. Scientists simultaneously monitored electrical brain activity with EEG and cerebrospinal fluid movement using functional MRI.
According to MIT, correctly timed sound stimulation increased the amplitude of both slow electrical brain waves and the associated waves of cerebrospinal fluid. The researchers also observed changes in blood-vessel volume that help drive the movement of fluid through the brain.
During sleep, this process contributes to the removal of metabolic waste. Researchers believe that understanding how to influence these mechanisms could eventually be useful for studying sleep disorders and diseases associated with the accumulation of abnormal proteins, including Alzheimer’s disease.
However, the findings do not yet represent a new treatment. The experiment involved only 14 healthy participants, and further research is needed to determine whether increasing cerebrospinal fluid movement actually improves sleep quality or the removal of unwanted substances from the human brain.
