A Lucid Death: Sparks of Consciousness Detected in Dying Brains

Summary: A groundbreaking new study provides early evidence of consciousness in the dying brain, shedding light on the mysteries of near-death experiences.

Researchers have identified increased gamma wave activity, associated with consciousness, in the dying brain of comatose patients. The activity was detected in a neural hotspot associated with dreaming and altered states of consciousness, providing exciting new insights into the human mind.

Although caution is advised due to the small sample size, this research could change the way we understand death.

Highlights:

1. A new study provides early evidence of increased activity correlated with consciousness in the dying brain.
2. The study identified four patients who died of cardiac arrest in hospital while under EEG monitoring. Two of the patients showed an increase in heart rate as well as an increase in gamma wave activity, believed to be the most rapid brain activity and associated with consciousness.
3. Activity was detected in the so-called hot zone of the neural correlates of consciousness in the brain, the junction between the temporal, parietal and occipital lobes at the back of the brain.

Source: University of Michigan

Reports of near death experiences– with stories of white light, visits from deceased loved ones, voices heard, among other attributes – capture our imaginations and are deeply embedded in our cultural landscape.

The fact that these reports share so many common elements raises the question of whether there is something fundamentally real underlying them – and that those who managed to survive death provide insight into a consciousness which does not go away completely, even after the heart stops beating. .

A new study published in the Proceedings of the National Academy of Sciencesprovides early evidence for a surge of consciousness-correlated activity in the dying brain.

The study, led by Jimo Borjigin, Ph.D., associate professor in the Department of Molecular and Integrative Physiology and the Department of Neurology, and his team follows animal studies conducted nearly a decade ago in collaboration with George Mashour. , MD, Ph.D., founding director of the Michigan Center for Consciousness Science.

Similar signatures of gamma activation have been recorded in the dying brains of animals and humans during oxygen loss following cardiac arrest.

“How living experience can emerge from a dysfunctional brain during the dying process is a neuroscientific paradox. Dr. Borjigin has conducted an important study that helps shed light on the underlying neurophysiological mechanisms,” said Mashour.

The team identified four patients who died of cardiac arrest in hospital while under EEG monitoring. All four patients were in a coma and unresponsive. They were ultimately determined to be beyond medical help and, with their families’ permission, removed from life support.

Upon removal of life support, two of the patients showed an increase in heart rate as well as an increase in gamma wave activity, believed to be the most rapid brain activity associated with consciousness.

Additionally, activity was detected in the so-called hot zone of the neural correlates of consciousness in the brain, the junction between the temporal, parietal and occipital lobes at the back of the brain. This area has been correlated with dreams, visual hallucinations in epilepsy, and altered states of consciousness in other brain studies.

Both of these patients had previously reported seizures, but no seizures in the hour before their deaths, explained Nusha Mihaylova, MD, Ph.D., an associate clinical professor in the Department of Neurology who has worked with Dr. Borjigin since 2015. by collecting EEG data from deceased patients in intensive care.

The other two patients did not show the same increase in heart rate upon removal of life support, nor did their brain activity increase.

Due to the small sample size, the authors caution against making overarching statements about the implications of the results. They also note that it is impossible to know in this study what the patients experienced because they did not survive.

“We are unable to make correlations between observed neural signatures of consciousness and a corresponding experience in the same patients in this study. However, the observed findings are definitely exciting and provide a new framework for our understanding of covert consciousness in dying humans,” she said.

Larger multicenter studies, including EEG-monitored intensive care patients who survive cardiac arrest, could provide much-needed data to determine whether these bursts of gamma activity are evidence of hidden consciousness, even when approaching. of death.

Other authors of this article include Gang Xu, Duan Li, Fangyun Tian, ​​Peter M. Farrehi, Jack M. Parent, and Michael Wang.

About this Consciousness Research News

Author: Kelly Malcolm
Source: University of Michigan
Contact: Kelly Malcom – University of Michigan
Picture: Image is credited to Neuroscience News

Original research: Free access.
“Increased neurophysiological coupling and connectivity of gamma oscillations in the dying human brain” by Jimo Borjigin et al. PNAS

Abstract

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

The brain is assumed to be hypoactive during cardiac arrest. However, animal models of cardiac and respiratory arrest demonstrate increased gamma oscillations and functional connectivity.

To determine whether these preclinical findings translate to humans, we analyzed electroencephalogram and electrocardiogram signals in four dying comatose patients before and after removal of ventilatory support.

Two of the four patients showed a rapid and marked increase in gamma power, an increase in the interfrequency coupling of gamma waves with slower oscillations, and an increase in functional and directed interhemispheric connectivity in the gamma bands.

The high-frequency oscillations parallel the activation of beta/gamma cross-frequency coupling in the somatosensory cortices. Importantly, both patients showed bursts of functional and directed connectivity at multiple frequency bands in the posterior cortical “hot zone,” a region postulated to be critical for conscious processing. This gamma activity was stimulated by global hypoxia and further increased as cardiac conditions deteriorated in dying patients.

These data demonstrate that the surge in power and gamma connectivity seen in animal models of cardiac arrest can be seen in some patients during the dying process.