Earlier quoted context omitted.
The specific technique here is unihemispherical sleep. Stimulating one side of the body while resting the other (one eye closed) to get one hemisphere to fall asleep. I think Gwen originally developed this trick to probe the mind and see if behavior was altered when one hemisphere was asleep versus the other. However, it turns out that when you do this, the brain as a whole does not get adequate sleep, even if you al…
Please note that there's no real evidence that single-hemisphere sleep is a thing in humans. Some sleep researchers suggest that a brain hemisphere can spontaneously be awake during ordinary sleep in "unfamiliar" places, and that this can be a cause of poor quality sleep - but that's a very different thing from what Ziz claims to be able to do. Also, to the best of my knowledge, Gwern has never written anything on hi…
And unihemispheric sleep (Gwen’s word for what they do; they like to invent their own terms) is one of the techniques the Ziz cult uses.