What does it feel like to die? We’re getting closer and closer to knowing (and it doesn’t seem that bad).
“Oh wow, oh wow, oh wow.” Before he died, the founder of Apple, Steve Jobshe proclaimed these words of astonishment. We don’t know why, but we are getting closer to finding out, some scientists believe.
We already know that the brain may not “turn off” immediately and passively in the final moments of life. There are several reports of brief bursts of neural activity highly coordinated shortly before brain death occurs — even in patients who no longer had this mental capacity for a long time — and even more reports from survivors of , who describe intense memories, a feeling of “clarity” and visions.
In recent years, research teams have begun to analyze electroencephalogram (EEG) recordings obtained from patients who died while being monitored, in an attempt to map the “last chapter” of brain activity.
They first concluded that stopping the heart does not immediately equate to death of the brain. Even when blood flow is interrupted, brain cells are able to maintain some activity for a short period, as they have energy reserves. The end of the heartbeat is not, technically, the end of us.
As neurosurgeon and neuroscientist Ajmal Zemmar explains, cited by , brain death occurs later, probably more than a minute after the heart stops. From an EEG point of view, this corresponds to the moment when the recording shows the effective interruption of the brain’s electrical activity. When the brain stops receiving oxygen — a condition called hypoxia — a sequence of events is triggered.
First, a abrupt increase in activityinterpreted as an emergency response by the organism, possibly linked to instinctive survival mechanisms.
Afterwards, a phase of low frequency brain wavesfollowed by electrical “silence” on the EEG.
During hypoxia, the cell death. One of the most important processes is called depolarization: neurons lose their electrical charge, which causes a chain release of neurotransmitters and ions such as sodium, potassium and calcium.
In animal studies, this mechanism has been associated with a large “wave” of post-shutdown activitydescribed by Zemmar as a kind of signature in three phases — a “tripasic wave” in which neurons fire in an uncontrolled manner, comparable, in the researcher’s metaphor, to a fireworks ending.
The decisive question is whether this phase corresponds to any conscious experience.
For Zemmar, if there is subjective perception, it must occur earlier, at the initial moment of greatest activity, when the observed pattern is more coordinated. Unlike chaotic depolarization, this organized “burst” resembles states in which the brain normally synchronizes neuronal networks, for example during meditation or demanding cognitive tasks. But records are few and, in most cases, patients are not aware and cannot report what they feel.
One of the analyzes that reinforces this hypothesis was conducted by researchers at the University of Michigan, who collected data from four patients who died while being monitored by EEG and electrocardiogram (ECG) in a neurointensive unit. Everyone was unconscious, but the devices recorded brain activity continuously in the minutes and seconds before brain death. In two cases, there were almost no marked changes; in the other two, researchers observed a relevant increase in gamma waves few seconds after removing the fan.
Gamma waves are the highest frequency among the classic EEG patterns and are, in general, associated with complex cognitive processing and information integration — phenomena often linked to states of consciousness. In this study, coordinated activity appeared mainly in temporo-parietal and occipital regions, areas that make up the so-called “hot zone” posterior cortex, often associated in the literature with essential components of conscious experience.
For Jimo Borjigin, the neuroscientist who led the investigation, the results contradict a dominant idea: that, close to death, the brain simply “gives up” and progressively reduces activity to zero. On the contrary, the data suggest that a brief “hyperactivation” phaseparticularly in the range, before the final collapse.
Previous studies have also reported spikes in brain activity after withdrawal of life support. A set of cases described in 2009 identified an increase in activity in seven patients shortly after stopping support; a follow-up study in 2017 found similar patterns at close frequencies, in around half of the patients analyzed. Still, not all studies confirm this type of explosions, and this inconsistency fuels a new question: why do only some brains show this pattern?
The subjective experience remains, for now, impossible to determine. Even so, Borjigin raises the hypothesis that these signs may correspond to a “neural signature” of NDE. In part, because the data points to strong activation of areas related to memory, which echoes common reports from survivors: reviewing life, vivid memories, or the impression of seeing loved ones. The hypothesis is that hypoxia triggers a cascade that activates evocation circuits, even without external stimuli.
If this final “wave” is indeed linked to memory, it could help to clarify not only the process of dying, but also bigger riddles about consciousness: how the brain constructs subjective experience and why it mobilizes energy to generate memories at a time when, at first glance, this does not offer an immediate advantage.
