The Search for Meaning in a Mysterious Brain Signal at Death
In 2016, an 87-year-old man went to the emergency room at Vancouver General Hospital after falling down. A CT scan showed that his brain was bleeding, and he needed surgery. After the operation, the man was stable for two days, but then he started to decline and have seizures.
Because of the seizures, his doctors measured the electrical signals from his brain using an electroencephalogram, or EEG. While the electrodes were on his head, the man had a heart attack and died.
A study published at the end of February documented what was found during the recording: In the 30 seconds before and 30 seconds after the man’s heart stopped, there was a surge in brain activity—and not just any activity, but gamma waves. Brain oscillations, or waves, are patterns of coordinated brain activity; gamma waves are associated with conscious states, including learning and memory, and have also been observed in meditative states.