Oh joy! We are all talking about Brain Inference! All of your sense organs (visual, auditory, cutaneous, vestibular, and olfactory) use memories to help infer information to places. This becomes more common with higher developed countries like the US. These inferences could totally be called hallucinations! Your brain is ALWAYS inferring things about your reality, and in effect controls it. The visual system makes the most inferences for example. Your brain is always looking for more symmetry and patterns; thats why people with very symmetrical faces are found to more "Beautiful". We are constantly seeking higher order(lower entropy) geometrically. Once on a salvia trip I stared at a large sign with a distinct pattern on it, and once i looked around the pattern was PASTED over everything that I looked at for around 3-4 minutes. As far as auditory goes, while extraordinarily high I was lying in bed and all of a sudden the Beck - Cellphones Dead song started playing as if I had left it on in my study. I sprang up and ran to check if my PC was on, and it wasnt. Vestibular hallucinations are great, and can be induced with Cannabis as well as mushrooms and .. alcohol - I guess. Lying down under the influence of one of these and you can feel as if you are actually spinning at an extremely high velocity, almost as if your feeling the earths actual rotational speed, which by the way is INCREDIBLY AMAZING! I plan to provide at great argument, proof, or some form of evidence linking our Perceptual Worlds, Psychedelics, and our Physical world. I do not believe that someone "hallucinating" is experiencing something that is not "real" and is just as "real" as someone waiting in line at a market. I will make it my Life's work to contribute to this as much as I can.