With a few sudden, traumatic exceptions (such as a fall from a great height or a catastrophic accident like a car wreck), death is a gradual process. It typically takes a bit of time for the body to fully shut down. In the interim between when the heartbeat or breathing stop and decay sets in irreversibly is a brief window, a sort of life buffer zone.
In this zone, interventions can be life-saving. This is when CPR may restart a heart, fill the lungs, circulate the blood and carry oxygen until the body functions are restored. If no interventions occur during this period, the brain’s “power-down” sequence begins.
And it is during this brief “buffer zone” that scientists have identified an unexpected burst of high-frequency, organized brain activity. Dubbed the “Death Wave,” this electrical flare of appears to be triggered by lack of oxygen and resembles the neurological activity of our higher function cognition, usually beginning in the same area as higher-level thinking processes in a region associated with dreams and altered consciousness.
What exactly is happening, here?
Brainwaves
The brain works through electrical activity we know as brainwaves. Brainwaves are distinguished from each other into 5 main types, separated according to how strong they are, with level 5, gamma waves, being the highest; the “death wave” flares up through them all.
These are the most widely used labels for levels and brainwaves; there are more for specialized states:
- Level 1: Delta, 0.5-4 Hz
- Level 2: Theta, 4-8 Hz
- Level 3: Alpha 8-12 Hz
- Level 4: Beta, 12-30 Hz
- Level 5: Gamma, 25-100 Hz
Brainwave strength is determined by measuring how many waves happen each second. Waves per second is a unit of measurement called “hertz” (Hz).
Increased Hz is associated with higher levels of mental arousal, attention and focus. The more waves per second, the more electrical activity is going on in the brain, though it isn’t quite a simple as one type of wave per task type: the brain produces and processes electrical types and intensities from its different regions constantly. But we accomplish tough tasks at a stage of “mental high voltage”, with higher gamma wave involvement (math, second language learning) less-demanding tasks (like parts sleep) use lower level brainwaves.
With so much activity at this intensity happening at the time of death in regions of the brain associated with dreams and altered conscious states, some question whether the measurable phenomenon is in fact scientific evidence of the near-death experience.
Seems backwards?
That last neurological hurrah It isn’t really what you’d expect if you’re thinking along the terms of a car running out of gas… you’d think brain function, like consciousness, would just peter out gradually, bit by bit, like water down the drain until all activity stopped. And indeed, for many the findings run counter to intuition while others see the brain making a sort of hypoxic Hail Mary play, a last-ditch, oxygen-seeking flailing grab at life.
Whatever the underlying mechanism, those who survive what they believe to have been their own death (science may not always agree on the state of “clinical death”) to tell tales of experiences they take to be “from the beyond,” and a good chunk of these do appear potentially to be somewhat substantiated, in a way, by science.
The precise nature of the experiences themselves is up in the air either way, of course; however convincingly documented, “death wave” activity has been frequently associated with areas of the brain known to be active during dreaming. So there’s that.
I wonder if anyone has ever done a study among those reporting out of body or near death experiences whose brain activity was monitored but showed no “death wave” or shenanigans in areas of the brain that might make it easy to write them off as dreams?
Hmm…
