This could be sort of like a debug mode of your brain where you can enter a dream like state while being conscious and forming permanent memories as opposed to

This could be sort of like a debug mode of your brain where you can enter a dream like state while being conscious and forming permanent memories as opposed to sleep where you lose your dreams when you wake up. I feel the 'spirits' they encounter are abstract personalities that the person forms this is why they don't need to speak to communicate. If you can switch from work mode to family mode when your kid enters the room, what guides you? They are probably encoutering parts of their own personality with the addition of a dream like state where the brain just fills in gaps and creates a narrative out of seemingly unconnected dream sequences.. they are probably real because they are 'you' + some imagination thrown in..