Uncoiling the spiral: Maths and hallucinations
plus.maths.org
plus.maths.org
On a related note, here's an interesting article from 2015 about encrypting information so that only people who are on LSD can read it: https://qualiacomputing.com/2015/05/22/how-to-secretly-commu...
The article seems to be interesting, but this start turned me off a bit, as it is wrong. Cannabis is not hallucinogenic. When you get hallucinations from cannabis, then you might have a problem called psychosis...