Here is a 17 minute TED talk that discusses how the brain perceives the world. It delves into the notion that we are all in fact hallucinating all the time, even non szs; and that it is quite easy for the mind to be tricked.
It talks about how reality can get over stimulated and have uncontrolled hallucinations in pyschosis and altered states and uses the deep mind AI to illustrate it.
It is a very interesting talk and introduces the concept of hallucinations and is well worth the 17 minutes of your time to understand such things.
Enjoy!