An ongoing international study of people who have survived severe cardiac arrest has led researchers to believe that the brain experiences a “hyper-alerted state” after clinical death. This means, they theorize, that consciousness could continue after the body stops showing signs of life; a person may be able to hear and perceive the pronouncement of their own death.

In 2016, after saxophonist Dan Fabbio was diagnosed with a brain tumor, neuroscientists in Rochester, New York, used functional MRI scans to create a brain map indicating areas crucial for music processing. Fabbio was awake during the surgery and, once the tumor was removed, played a Korean folk song to ensure his skill on saxophone remained; the song’s short notes allowed him to take shallow breaths so his brain would not protrude from his opened skull.

George Romero, who pioneered the modern zombie film in 1968, complained in 2010 that he’d “never had a zombie eat a brain, but it’s become this landmark thing.” The trope was introduced in 1985 by Dan O’Bannon’s Return of the Living Dead, in which a zombie woman explains that eating brains relieves the “pain of being dead.” Some fans have speculated this is due to the brain’s high levels of serotonin.

According to medieval Egyptian scholar al-Nuwayri, the ancient sages claimed that “when lovers breathe into each other’s faces, their breath mixes with the air,” is inhaled through their noses, and then “reaches the brain, into which it spreads like light in a crystal vessel.”