But how late is too late? For Gosseries, brain death—marked by the irreversible loss of brainstem reflexes (like pupil response to light or the gag reflex)—is the medical definition of death.

A new study shows that even complex mammal behaviors can be influenced by single, evolved regions of the brain.

Home > Science Flee or Freeze: How Evolution Hard-Coded a Life-or-Death Reflex A new study shows that even complex mammal behaviors can be influenced by single, evolved regions of the brain.