Anil Seth makes a distinction between "controlled hallucinations" (best guesses) as opposed to "uncontrolled hallucinations" which are random delusions produced by a overstimulation of sensory experiences. He explains that controlled hallucinations are produced by a simple feed back system whereby the brain reaffirms its "best guess" by confirmation with the exterior input. A kind of double check but this time it is comparing the internal hologram with the exterior object, rather than the other way around. The input from exterior is processed by the "afferent" neuron system, the confirmation to the exterior and internal motor responses are produced by the "efferent" neural system. (CNS=Central Nervous System) https://pediaa.com/difference-between-afferent-and-efferent/ Thus controlled "seeing" comes from the inside out as much as from the outside in. If the internal hologram presents a distorted picture then we enter a delusional state. Anil Seth observes that this is actually a very fragile balance, which can go wrong from a host of interferences. And again, even as we know that optical illusions present a false representation of reality, the brain still tells us what it's best guess is even as we know it is wrong......very disturbing in a way......Please Register or Log in to view the hidden image! But with an optical illusion we know its an illusion, so we need only admit to ourselves it is an illusion, to keep our mind from going ..poof!.........Please Register or Log in to view the hidden image!....... Please Register or Log in to view the hidden image!.......Please Register or Log in to view the hidden image!