Pairing a painful stimulus with activation of the amygdala train rats to want the painful stimulus, possibly explaining why masochists desire pain.

Masochist pain activates brain areas involved in empathy, emotion and consciousness, but not in addiction.

In BDSM, sub space is an altered state of consciousness mediated by adrenaline and endorphins.

Masochists enjoy pain by itself and to achieve sub space, focus, catharsis, empowerment, orgasms, vulnerability and intimacy.