Researchers have also studied the right temporoparietal cortex, an area of the brain responsible for processing information about the body in space. When this region malfunctions—whether through trauma, seizure, or oxygen deprivation—it can produce the feeling of floating outside the body or moving through a tunnel.

From this perspective, NDEs aren’t windows into another world, but the brain’s final protective illusions.

A Mystery Across Cultures

Still, what makes NDEs intriguing is how consistent they are across different cultures and time periods.

Ancient Egyptian texts describe journeys into other realms after death. Tibetan Buddhism teaches about the “bardo,” a transitional state between death and rebirth. In some Indigenous traditions, people speak of traveling across a bridge or river to meet ancestors.

While the imagery varies, the themes—light, peace, familiar presences—show up again and again.

Even among modern survivors, similarities emerge:

A feeling of leaving the body
A perception of moving through darkness toward light
Encounters with guiding beings
A review of one’s life
A decision or command to return
Brianna’s account fits neatly within these patterns, yet has its own unique twists—like the concept of the universe being made of numbers.