The understanding that there is no "you" watching a movie constructed by "your visual system" is actually a great explanation for these kinds of experiences. I

The understanding that there is no "you" watching a movie constructed by "your visual system" is actually a great explanation for these kinds of experiences. In order for you to experience a psychedelic hallucination of a face, there doesn't actually need to be a face constructed anywhere in your brain; all that needs to happen is for you to _believe_ that you saw a face. If something causes your "face detector" system to light up, you will think you saw a face whether or not a face was there. This brings the possibility of psychedelic experiences within the fathomable; it's not like you have some massive GPU in there constructing complex animations that the rest of you is watching.