The study on pink noise and deep sleep

In describing the developments of their study, the researchers explained that in the analysis they used an auditory stimulus composed of short emissions of 50 milliseconds of pink noise, administered to 14 healthy volunteers at a specific moment during sleep. Specifically, this is the phase in which the peak of the slow waves associated with deep sleep is recorded in the brain.

Already in other previously published reports, scientists had demonstrated that these brain waves are closely connected to the movement of cerebrospinal fluid, i.e. the transparent liquid that surrounds and protects the brain and spinal cord, providing nutrients and removing waste products. According to what emerged from this latest study, in fact, pink noise pulses, administered without causing awakening, increased the amplitude of slow brain waves. As a consequence, these stimulated the constriction and dilation of the blood vessels, setting in motion a sort of pump that pushes the cerebrospinal fluid out of the brain. The result, the experts reported, was also an increase in the amplitude of the waves that move the cerebrospinal fluid.

By virtue of this research, scientists will also try to understand more closely whether enhancing the flow of cerebrospinal fluid can help achieve more restful sleep, especially in those who tend to suffer from insomnia. But not only that, because a further aim will be to verify whether increasing the flow of liquid, thus favoring the removal of waste substances from the brain, can help people suffering from Alzheimer's and other neurodegenerative pathologies, characterized by the accumulation of harmful proteins.