Several near-death experience reports have covered tales of hearing voices, seeing departed loved ones visit, and other attributes. All of these have led to the question regarding whether there is something that actually underpins these attributes.
Near-Death Fleeting Consciousness?
A recent study reported in the PNAS journal offers evidence regarding surging brain activity in the dying human brain that is linked to consciousness. Similar gamma activation signals were also documented in human and animal dying brains as they lost oxygen after a heart attack.
According to Science Daily, this study follows animal studies that were done nearly a decade ago. It was led by Jimo Borjigin, Ph.D., an associate professor in the University of Michigan's Department of Neurology and the Department of Molecular & Integrative Physiology.
George Mashour, M.D., Ph.D., the Michigan Center for Consciousness Science's founding director who also took part in the nearly-ten-year-old animal studies, explains that the emergence of vivid experience in a dysfunctional brain as it nears death is quite a "neuroscientific paradox." Dr. Mashour adds that Dr. Borjigin's efforts shed light on the neurophysiological mechanisms that underlie such phenomena.
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Dying Human Brain's Waves
The research team identified four individuals that died due to a heart attack at a hospital as they were monitored by the EEG. All of these patients were unresponsive and comatose. Ultimately, their cases were evaluated to be "beyond medical help." Then, with the permission of their family, life support was removed, as reported by Science Daily.
As per Live Science, roughly 30 seconds to two minutes after the ventilators were taken away, two patients' brains demonstrated a gamma wave surge. This is the fastest brain activity and it is commonly linked to consciousness.
This activity appeared quite organized in such a way that the waves in a particular region of the brain were linked to predictable patterns of activity across other areas.
More specifically, the temporoparietal junction exhibited higher gamma wave activity. Located behind the ear, this brain region is where the parietal and temporal lobes meet. Dr. Borjigin also notes that the region is known to be activated when people dream or experience altered consciousness states or even visual hallucinations in cases of epilepsy.
Nusha Mihaylova, M.D., Ph.D., a colleague of Dr. Borjigin since 2015 and a clinical associate professor from the Department of Neurology, explains that these two individuals had a history of seizures. However, they did not experience seizures an hour before their passing.
The other two patients, however, did not demonstrate similar heart rate increases after life support was removed. No increased brain activity was also observed.
Study Limitations
While these findings are quite significant, the study is limited by the small sample size and other factors. The authors warn against making generalized conclusions regarding the findings' implications. They also add that it is not possible to know the exact experience of the patients, since none of them survived.
Dr. Mihaylova explains that they are incapable of correlating the neural signatures with fleeting consciousness experiences. Nevertheless, the findings are quite exciting and offer a new way of viewing fleeting consciousness among dying humans.
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