What do I do if I am trying to practice emptiness of mind and hypnagogic (pre-sleep) imagery keeps coming up? They aren't entirely consciously controlled, more like random images that pop into my head, and my mind is fuzzied from fatigue or something so I have a harder time focusing. Should I just refrain from EOM practice if I am somewhat sleepy, or is this a common phenomenon which represents the next layer of "thoughts" to be eliminated? Thanks, David