Also, the metaphorical "little voice in the back of your head" that tells you what you're about to do is a bad idea.. Apparently people really hear that too? It would be nice to read about the differences between genuine hallucinations and mental imagery or sound from someone familiar with both. Obviously there
are differences but people just get offended or simply weirded out most of the time when you ask.
Also you might find it interesting to read Jaynes' Breakdown of the Bicameral Mind. It's evidently controversial and not a viewpoint to uncritically adopt wholesale, but it does get you thinking about mental visualization/audiolization vs. hallucinations etc... and contains some intriguing historical anecdotes.