 In the 1990’s, interest revived in studying meditation and psychedelic drugs to see what they may reveal about how the brain works. Different meditative techniques (especially mindfulness meditations) are now being studied through neuroimaging to gain data on the brain activity occurring during these experiences and practices. (For an overview, see Schjoedt 2009.) Losing a sense of a phenomenal “self” necessarily alters our ordinary ego-driven state of consciousness. (See Millière et al. 2018 for an overview on different senses of “loss of self” and their phenomenological differences.) Thus, the phenomenology of mystical experiences also has become an important subject for the study of consciousness. As noted in Section 8, neuroscientists are finding unique patterns of brain activity during mystical experiences. Different neurophysiological effects and unique patterns of brain activity have also been detected in mindfulness practices and in introvertive concentration practices (Hood 1997 and 2001; Dunn, Hartigan, and Mikulas 1999). The neurological effects of concentration differ from those of mindfulness meditation (Valentine and Sweet 1999). This suggests as strongly as neuroscience can that the mystical experiences enabled by meditation differ from more ordinary experiences and our normal waking state of consciousness and that the effects of different types of meditations are distinguishable. Possible neural correlates of different mystical features — a loss of a sense of self, a sense of connectedness to others, a feeling of certainty, feeling the experience has great significance, loss of a sense of time — have been identified. For example, a loss of a sense of self is correlated to the decrease of activity in the brain connected to a sense of self and a sense of separation from the world.