Possibility that this is a sick display of the DS telling us what they are doing??

Link: https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/brain-waves

"Delta is prominently seen in brain injuries, learning problems, inability to think, and severe ADHD. If this wave is suppressed, it leads to an inability to rejuvenate the body and revitalize the brain, and poor sleep".