Very interesting article, Luke, I think I might try some of those echolating exercises.

A somewhat random observation: I dream in color but I hallucinate in black and white. I've only ever hallucinated in dark rooms when I've just woken up so I suppose this is not terribly surprising.

Although I very rarely have hallucinations it happens that I did have one the night before last. I woke up in the middle of the night and saw a toddler climbing the door of the room I was in with unnatural jerky motions. The toddler was about the same age as my daughter but was clearly not my daughter. If I looked away from the door everything seemed normal but when I looked at the door again the toddler was still there. My wife and daughter were asleep in the same room at the time. Since I find hallucinating mildly distressful I thought about waking up my wife but in the end decided not to bother her, closed my eyes and went back to sleep.

I had consumed alcohol in moderation the evening before and I was coming down with a mild case of flu. We were away from home. I don't know if any of these was a causal factor.

I've had visual hallucinations a few times before. On one occasion I had an auditory hallucination - I found that significantly more unnerving.