Where did you get this idea from?

A variety of experiences.

It detaches one from one's interpretations of reality. Like you meditate and hear a sound. It teaches you to not instantly go and think "hey, that is a dog barking" and thus replacing the experience of a sound with a concept, with a mental category, but simply experiencing the sound directly without attaching any label to it.

The effects of meditation a bit more complex. I don't want to go to much in the detail here because that would mean that I would have to use words like "energy" with I don't use on LW.

Meditation is a beautiful thing, but it has effects. When it comes to a person who already sees spirits I would treat very careful.