First Scan of a Dying Human Brain Shows Life Flashes Before Eyes

In a recently published study in Frontiers in Aging Neuroscience, a team of researchers claimed that they had captured a recording of a dying human brain for the first time.

The startling discovery was made in 2016 while researchers studied the brain activity of an 87-year-old Canadian man who had developed epilepsy.

After a fall that resulted in a bleed in the brain, the man was admitted to a hospital emergency department and subsequently deteriorated. Doctors discovered the patient had epilepsy after performing electroencephalography (EEG). However, during the EEG recordings, he had a heart attack and died.

However, scientists unintentionally captured unique data on his brain activity at the end of his life. The researchers recorded approximately 900 seconds of brain activity prior to and immediately following the patient's death. 

During the 30 seconds before and after the man's heart stopped, patient brain waves were remarkably similar to those seen during dreaming, memory recall, and meditation, implying that people may appear to have a sudden flash of memories seconds before and after his heart stopped beating.

Dr. Ajmal Zemmar, a co-author of the study, stated that the team, which was based in Vancouver, Canada at the time, unintentionally obtained the first-ever recording of a dying brain.

"This was actually totally by chance," he told the BBC, "we did not plan to do this experiment or record these signals."

According to the team, an analysis of recordings from 30 seconds before and after the man's heart stopped beating indicates that he experienced changes in different types of brain waves in his final moments, including alpha and gamma brain waves. The study suggests that interactions between different brain waves continue after the blood stops flowing in the brain.

"Just before and after the heart stopped working, we saw changes in a specific band of neural oscillations," said study co-author Dr. Ajmal Zemmar, a neurosurgeon at the University of Toronto in Canada at the time of the man's case. These oscillations are referred to as gamma waves, according to Zemmar.

The frequency and amplitude of neural oscillations are used to classify them. For example, gamma waves have the highest frequency of any oscillations, between 30 and 100 hertz. They are most commonly observed in the brain when people access their memory center in the hippocampus region.

The findings revealed that as the person died, there was an increase in brain waves known as gamma oscillations, which typically occur during dreaming and memory retrieval, and others such as delta, theta, alpha, and beta oscillations.

Brain waves are rhythmic electrical activity in normal living human brains, and different types of these waves are associated with different states.

However, because the new study is based on a single patient who also had injury, seizures, and swelling, researchers said the interpretation of the data might be complicated, adding that more cases need to be investigated.

Despite the limitations of only studying one case, the findings built on a 2013 study in rats found similar brain activity patterns before and after death, leading some to speculate that memory recall may be a universal experience of dying mammals.