What Does the Brain Experience When We Die?

No one can ask a person what they experience as they die. Scientists can only record the brain, and very rarely get the chance. This article describes what those few recordings have shown, and how cautious researchers are about them.

What did the 2023 study find?

A surge of fast brain waves in two of four patients. Scientific American describes a study published in PNAS by Jimo Borjigin and colleagues at the University of Michigan. It included four comatose patients who were dying in intensive care after cardiac arrest, and whose families agreed to have life support removed. In the 30 seconds to two minutes after the ventilators were removed, two of the four showed surges in gamma waves, the fastest brain rhythm. A commentary says the other two showed only large, slow waves that faded to a flat line within a few minutes. The last heartbeat came within 10 to 25 minutes of removing the ventilator.

Where in the brain was it?

In a region where the temporal, parietal, and occipital lobes meet. The University of Michigan team notes that this area is believed to be involved in consciousness and is active during dreaming, seizures, and out-of-body hallucinations.

Had this been seen before?

In animals and in one person. Smithsonian Magazine reports that in 2013 Borjigin found that rats’ brains produced surges of gamma waves for about 30 seconds after their hearts stopped. Scientific American says that in 2022 doctors were recording an 87-year-old man’s brain when he died unexpectedly. They saw a similar surge in the 30 seconds before and after his heart stopped.

What do researchers say about it?

That it is intriguing, but uncertain. The 2023 study had only four patients, and the two with surges also had a history of seizures, according to the University of Michigan. ScienceAlert reports that the surges came with widespread low oxygen in the brain. The authors wrote that they could not rule out that the surge is a sign of a pathological process specific to dying and unrelated to consciousness. Scientific American notes that co-authors of the earlier study are optimistic that such signals could reflect conscious experience, but that another researcher, Daniel Kondziella, is more skeptical. Borjigin told Smithsonian Magazine the finding needs to be confirmed in more patients.

How does this fit with the AWARE II study?

It points in the same direction. AWARE II found near-normal brain activity in some patients up to an hour into CPR, but no one with those recordings recalled an experience. See What Happens to Consciousness During Cardiac Arrest?. For what people report, see What Is a Near-Death Experience? and Scientific Theories Explaining Near-Death Experiences.