When one is nearing sleep, their functions seem likened that of a quiet drunk. Existing with life in slow motion with a slower reaction to it. These states are intriguing in the way that one can peer into the thinner veils of the psyche when it is under the stress of sleep pressure only. Where other substances provide a body working overtime to keep itself alive, sleep merely expresses the persona in a far calmer state (calm in fight or flight). In these moments, take note upon on the impulses and behaviour of the subject, it could provide a greater insight to their self in turmoil.
Meditate.