"My experiences with hallucinations (or more commonly illusions as usually they are distortions of objects that are actually there) are many. Mostly these have been in expedition length adventure races but have occurred in shorter 2-3 day races. Indeed I had some just this past weekend while competing in a race that took us 33 hours. Usually they appear when doing a monotonous activity and this weekend it was kayaking down a flat calm river in the bright morning sunshine when the riverside foliage took on the appearance and movement of various animals. I swear I saw rhino, a gorilla's head and a bull frog with the rear end of a squirrel. At that time, of Jim Duff's High Altitude Quintet I was only exhausted - mentally, as physically I felt fine - but definitely sleep deprived.
In a previous 1100km race in Sweden I remember riding through the night in drizzly rain on monotonous fire roads with millions and millions of tall trees that all looked the same. When we came out of the forest I remember seeing some farm buildings on stumps which took on the shape of African safari animals and in my mind started to chase us. My teammate told me they were stampeding after us and we had to sprint to get away from them. I genuinely feared we were going to get crushed and smashed out the next 10km at max effort until my team caught me to tell me they were only joking!
The 2016 World Adventure Racing Championships took place in the Shoalhaven region of New South Wales. The course was approximately 600kms long and teams of 4 covered the ground on foot, mountain bike and raft. Teams took anywhere between 4 and 9 days to complete the course.
At the tail end of the World Adventure Racing Champs in Oz in 2016, after 110 hours of racing with 5.5 hours of sleep my teammate was convinced he was playing tennis with a couple of teenagers - at 2am in the pissing rain after 20km of trudging along a flat sandy beach.
At 1000 miles long, the Iditarod is the world's longest winter ultra marathon. It takes place in Alaska and is undertaken on foot or mountain bike. Leading competitors take between 3 and 4 weeks to complete the course.
Another friend, Andy Heading, while racing his mountain bike alone in the Iditabike race in snowy Alaska spent a while conversing with the Pope who was sat on a rock eating chocolate biscuits. I have frequently seen sticks that look and move like snakes which scare the crap out of me (which is less concerning than the times when I'm not hallucinating and see actual snakes that look like sticks!).
Much less common for me at least have been the auditory hallucinations - perhaps mostly being with other people on my adventures has an effect on this?
Most of my visual symptoms seem to be influenced by the monotony of the activity that I've been doing - flat road/trail, flat water, repetitive actions - I can imagine similar issues with polar or ice cap travel and mountaineering in poor visibility/whiteouts. The tired brain seems to want to fill in the gaps for whatever reason. We use No Doze/Pro-Plus tablets a lot to help - I'm not sure if this is something high altitude mountaineers frequently use on summit pushes? I don't think, for me anyway, that it's been related to fear - I'm usually at my most alert and best mental clarity when I'm shitting myself or hurting like crazy!
I haven't ever been to high altitude, other than Mont Blanc summit, but that was a quick run up and down on a beautiful day so little time for altitude problems to occur, so I can't really comment on Jim Duff's High Altitude Quintet. While I have frequently been cold, mildly dehydrated, tired and hunger flatting, I've never been hypoxic and my symptoms have occurred with or in isolation to any of them.
It's a fascinating aspect of endurance activities and thankfully for me all these visions have been harmless, but I do wonder if other see or hear things that encourage them to do something more risky or harmful with disastrous outcomes..."
To address your article questions:
1 You hear your own thoughts spoken aloud in your head so that someone near might be able to hear them. Don't think so.
2 You have a conversation with a person who is not really there. Yes done that.
3 You sense the presence of another being, despite being unable to see any evidence. Yes.
4 You feel like you cannot distinguish if you are awake or dreaming. - Definitely
5 You see a person or person's face in front of you even if no one is in fact there. On a few occasions.
6 You see shapes, lights or colours even though there is nothing really there. - Yes.
7 You hear your own thoughts repeated or echoed. Yes, occasionally.
8 You hear sounds or music that people near you don't hear. Yes, definitely.
9 You hear voices saying words or sentences when there is no one around that might account for it. Rarely.
10 You find that your experience of time changes dramatically. 100%!
11 You see things that other people cannot. 100% - Although, even more interesting is when others in the team also see the same thing when we both know it isn't there!"
Exhaustion is clearly enough to trigger psychotic symptoms!
Thanks John for contributing to STDZ!