Out of curiosity I irrigated his left ear canal with ice water. This procedure is known to activate the vestibular system and can provide a certain jolt to the body image; it can, for example, fleetingly restore awareness of the paralysis of the body to a patient with anosognosia due to a parietal stroke. When I did this for Patrick, he was astonished to notice the twin shrinking in size, moving, and changing posture. Ah, how little we know about the brain!
