Does playing music during sleep actually suppress rather than rouse the brain?

Question

I've long been interested in the effect of music/sound on dreaming, and even built 2 apps that play music during REM period. Now I'm looking at this article about FMRI studies of a sleeping brain, and I see that it mentions:

During wakefulness, acoustic stimulation elicits activation of the auditory cortex (red). Similar stimulation during light NREM sleep stage 2 evokes transient downregulation of widespread cortical areas (blue), supposedly a sleep protective mechanism.

and

Acoustic stimulation in REM (rapid eye movement) sleep revealed a different brain activation pattern during phasic and tonic REM periods, with strongest suppression of cortical reactivity during phasic REM sleep periods.

Can I interpret information on that site to suggest that auditory stimulation during sleep actually makes the brain less active? Can one assume that playing audio during REM would disrupt dreaming due to transient downregulation?

Answer 1

This is a very interesting but difficult to answer question. That is because scientists are still debating about the various stages of consciousness. As it stands, there is evidence that people can learn even though they are asleep indicating that it is likely that sensory channels are open and information is being processed even when asleep. That likely means the brain is behaving as if it were awake at certain times during sleep. In this article they interpret the lack of blood flow seen by fMRI as less active which is mostly correct. Playing audio during REM is a tricky question because as you know dreaming does not require sensory input so that channel(hearing) may be free to receive information although your guess may also be true if if the music was loud enough to interfere with other cognitive processes.