Psychedelics are revealing how the brain builds the sense of self

Many people have reported moments when the sense of being a distinct self ‘loosens’. Among astronauts, it is called the overview effect while deep-sea explorers report a similar shift sometimes called the underview effect. Both involve sudden changes in perspective in which the usual boundary of ‘me’ briefly softens, as if the vastness they encounter is mirrored inwardly and the distance between self and world is momentarily absent.

This dissolution often translates into shared experiences of oneness and interconnectedness with the outside world.

The 19th century Indian teacher Ramana Maharshi treated this instability not as an anomaly but as something to examine directly. Continuing a long philosophical tradition, he invited people to look for the ‘I’ in their own experiences — in the body, sensations, and thoughts — and notice that none of them fully captures the true nature of the self.