[sonnyblarney]

Is this 'hallucination' though? Or just some weird stuff happening in visual processing?

I underwent some very serious periods of sleep deprivation (Army) and our 'hallucinations' were of a totally different kind: having conversations with people that were not there, seeing things that were not there, misidentifying people whom you know really well who are right on front of your face, taking on different personalities etc..

[lightbyte]

That sounds like deliriant hallucinations as opposed to psychedelic hallucinations. Deliriant drugs (such as Nutmeg, DPH, Datura, etc.) produce a completely different hallucination experience compared to psychedelics. Often times after taking these people do not even realize they are hallucinating everything that is happening (conversations, other people, going places) until they suddenly realize they have been simply walking around their bedroom for hours. I imagine these work in completely different ways on your brain.

[sonnyblarney]

Good point - definitely the 'lack of self awareness' is a big differentiator - that said, sensory and cognitive ability is seriously impaired to begin with in these scenarios of sleep deprivation/stress induction.

It's also very scary once you do realize that you've been having a conversation with 'nobody' (or a 'ghost' is what one might think) for quite some time - it adds quite a degree of neuroticism.

On a funny/scary note - the weirdest of all is seeing two people apparently 'having a conversation' ... but upon closer inspection you find they are just taking turns talking near gibberish at one another. All of the manner, body language and tone of a 'conversation' but really, it's just two temporarily crazy people mumbling ... with automatic weapons. Thankfully with no live rounds in most situations :)

[offbytwo]

> Is this 'hallucination' though? Or just some weird stuff happening in visual processing?

Is there a meaningful difference?

[toomanybeersies]

I would argue that yes, there is.

On LSD (at least up to moderate doses), you don't hallucinate anything that doesn't exist. You don't see anything that isn't there, or hear voices, everything is just an altered version of reality.

Hallucinations from sleep deprivation (and certain drugs) are different though, you do start to see things that aren't there, often in the corner of your vision, and you do start to genuinely hear voices that don't exist. It's a surreal experience when you're suffering from severe sleep deprivation and you can hear your family talking to you, despite knowing that in reality they're 1000 miles away.