He also asked them what it was like. Most reported mystical experiences in which they lost their sense of themselves and felt they became absorbed into everything around them. That analysis was corroborated by the scans, which showed altered blood flows in parts of the brain known to handle our concept of self. It's bona fide research, in case you're wondering, peer-reviewed and published by the US National Academy of Sciences.
Such results are not entirely unexpected. The same thing has been observed in experiments scanning the brains of Franciscan nuns at prayer and Buddhist monks deep in meditation: the sense of self disappears and eternity and infinity take over.