1. There are invisible tiny people that only a specific mushroom that hits your brain in a very specific way can let you see
2. There aren't invisible tiny people but a specific mushroom that hits your brain in a very specific way makes you hallucinate a specific thing
0. There are tiny people who are not invisible but there is something that makes it so humans ignore them. That specific mushroom interfered with whatever that is so that we can see them.
An argument for #0 and in favor of #2 is the #2 requires the mushroom to cause an hallucination that includes a lot of generated detail to be realistic and consistent with how an actual tiny person would behave and affect the world.
#0 on the other hand is just turning something off.
An argument for #0 over #1 is that #0 does not require actual invisibility. If there were actually invisible tiny people we still probably would have discovered by now the physical mechanism that can make things invisible, which w e have not. Unless we are going to consider magic or psychic powers or some other such thing completely beyond known physics we can almost certainly rule out actual invisibility.
Also of course the tiny people do not seem to causally interact with their physical environment in any measurable way (at least to observers of the test subject) so that already strongly points towards hallucinations but that kind of thinking isn't how you get a grant.
If they aren't invisible, my cat would have caught and killed dozens of them, and then I'd be smelling their rotting corpses around my house and slipping on their bodies.
Also presumably they'd end up in many pictures, which even if we somehow ignored them still in all photographs AI would still see, as would car lidar systems, etc.
(I guess the likelier theory is that a mushroom that causes hallucination is causing hallucination)
What if we all see the exact same thing