There is much information out there these days that shows the subconscious mind doesn't know the difference between reality and imagination. That is why so many people use visualisations, affirmations, positive thinking and so on as methods of self-help. So when Hubbard was hooking himself up to a meter and letting his imagination run riot it isn't surprising that the meter was giving reads. He was imagining incidents, the subconscious thought they were real and caused the meter to read and Hubbard took the reads to confirm the incidents were real! Talk about the blind leading the blind. No wonder he ended up going nuts.