Surge of Neurophysiological Activity in the Dying Human Brain

Overview

The following research paper from the National Library of Medicine documents an experiment on brain dead patients and what occurred after being disconnected from life support. There is a tremendous spike in brain activity after death that seems to indicate the person is experiencing movement and talking to someone, as indicated by the part of the brain that lights up during this experience. The dying brain seems to indicate a conscious experience is occurring in the patients.

This experiment is compatible with the idea that human consciousness is external to the brain, and that the brain is only a physical organ that allows consciousness to interact with the physical body.

Proc Natl Acad Sci U S A 2023 May 9;120(19):e2216268120. doi: 10.1073/pnas.2216268120. E pub 2023 May 1


Surge of neurophysiological coupling and connectivity of gamma oscillations in the dying human brain


Gang Xu 1, Temenuzhka Mihaylova 2, Duan Li 1, Fangyun Tian 1, Peter M Farrehi 3, Jack M Parent 2 4 5 6, George A Mashour 4 5 7 8, Michael M Wang 1 2 4 5 6, Jimo Borjigin 1 2 4 5 8

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Free PMC article

Abstract

The brain is assumed to be hypoactive during cardiac arrest. However, animal models of cardiac and respiratory arrest demonstrate a surge of gamma oscillations and functional connectivity. To investigate whether these preclinical findings translate to humans, we analyzed electroencephalogram and electrocardiogram signals in four comatose dying patients before and after the withdrawal of ventilatory support. Two of the four patients exhibited a rapid and marked surge of gamma power, surge of cross-frequency coupling of gamma waves with slower oscillations, and increased interhemispheric functional and directed connectivity in gamma bands. High-frequency oscillations paralleled the activation of beta/gamma cross-frequency coupling within the somatosensory cortices. Importantly, both patients displayed surges of functional and directed connectivity at multiple frequency bands within the posterior cortical "hot zone," a region postulated to be critical for conscious processing. This gamma activity was stimulated by global hypoxia and surged further as cardiac conditions deteriorated in the dying patients. These data demonstrate that the surge of gamma power and connectivity observed in animal models of cardiac arrest can be observed in select patients during the process of dying.

Keywords: cross-frequency coupling; directed connectivity; functional connectivity; gamma oscillations; global hypoxia.

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Conflict of interest statement

The authors declare no competing interest.


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