In his book “Why We Sleep,” Mathew Walker explained that Alzheimer’s detection via EEG monitoring during sleep was a major reason he decided to switch to studying sleep 20 years ago. He was trying to originally study diseases like Alzheimer’s and found that there was not much information on why identification on EEG was detectable before symptoms occurred, such as forgetting items’s locations.

I wonder if this is along the same lines, like a wider variety of EEG signal detection, clearer or more accurate diagnosis, or something entirely different. It looks like subjects were still awake but in a restful state, so maybe testing also does not require as much time as a full sleep study.