Life After Death— the Science Behind Zombie Brains
Can the Dead Think?
Can a dead brain think and react to external stimuli? Until now, this possibility had been the realm of science fiction and horror movies. However, a recent peer-reviewed study has shown that brains which had been preserved in formaldehyde and alcohol for as long as twenty years after they had been removed from their body, still reacted to external stimuli in much the same way a living brain would. What’s more, these pickled brains showed cerebral activity nearly identical to that of living brains in the area of the brain most associated with personality, a sense of self, and core memories, which suggests the perseverance of some residue of the person deep inside a disembodied brain.
Science vs. Popular Culture
The idea that a severed brain floating in a specimen jar could still think and act has been a mainstay of Futurama, which features President Nixon and other celebrities leading a sort of afterlife in large mobile glass jars. It has also been the foundation of the current zombie craze in movies, television, and books, all of which are based on the idea that the unusually hungry undead are animated by a brain which has someone maintained at least a little activity following the demise of its owner.
In the entertainment universe, there is no consensus on how a dead brain could still make its corpse body lumber about in search of human prey. Some movies such as Romero’s Night of the Living Dead, left the question completely unanswered, though the fact that those who had been bitten by a zombie came back to life as flesh-eating zombies suggested some sort of infectious agent. In the Walking Dead, the zombies are said to be animated as a result of some sort of infection, but the process or nature of the pathogen is never clearly explained.
The Zombie Survival Guide, by Max Brooks, was the first book to take a “serious” look at how zombie brains might continue to operate, despite the death of the body. According to ZSG, zombie brains had been infected by a virus which preserved the brain and slowed decay, and as a result made away with the need for food, for oxygen, and all of the other things that living brains need.
The theory put forth in ZSG seems preposterous and not possible in real life. After all, the brain – like all of our other organs – needs oxygen and nutrients to survive or it begins to break down and decompose. But what if decomposition could be stopped or slowed down, such as when a brain is placed in a preserving solution?
Until now, the prevailing wisdom is that even though the visible structures of the dead brain might be preserved by immersing it in alcohol or formaldehyde, the underlying environment was so different from the conditions of life that no brain function could be possible. Except that no one had bothered to test that assumption, at least until now.
Starting from the observation that the structure of organs dictates their functions, a team of neurosurgeons set out to ask: if the structure of the brain remains intact, will its function survive?
The researchers took a number of brains and parts of brains which had been preserved in embalming fluid, for as long as twenty years, and subjected them to a number of stimuli ranging from electromagnetic, chemical and light. They then measured the brain’s reaction using essentially the same equipment that would be used to measure brain activity in a living brain.
The results were both shocking and disturbing. All of the dead brains that were tested, showed reactions nearly identical to the types of reactions that occurred in living brains when the living brains were exposed to the same kind of stimuli. Despite the fact that the dead brains had been without nutrients, without oxygen, and in some cases had been dissected, they continued to function at least on a basic level. What’s more, the activity elicited by these stimuli took place in areas of the brain that were associated with memory, with selfhood, and with personality.
The results led the researchers to make to understated but striking conclusions:
- The precise point beyond which the brain is no longer “living,” a threshold which remains unidentified, is perhaps less definite than has been historically assumed.
- [T]he post-mortem brain which displays subtle cortical oscillations, particularly within the theta and gamma bands as demonstrated here, could express some capacity for cognitive activation. (Cognitive = thinking.)
Nixon's Head in a Jar
What Do You Think?
Do you think that dead brains might still be conscious?
What Does This All Mean?
The study’s results are too new to fully map out all of the implications, but they hint at the survival of some sort of consciousness after death, at least until the brain decays to the point where its structures are no longer intact. Usually, the brain begins to irreversibly decay the moment that a person dies, but in cases where the brain has been preserved, as in the case of specimens in a jar or perhaps even in cryogenic sleep, it is possible that the brain – and perhaps its consciousness – persists. This is both fascinating and horrifying. Have we condemned thousands of brain specimens floating in jars in university labs throughout the world to a kind of half death? Could they be self-aware? Do they dream? Are they trapped forever in between life and death? Could this lead to a way to cheat death, like on Futurama, or does it mean that zombies are possible after all?
If some consciousness survives, what does this mean for Einstein’s Brain whose beautiful brain has been preserved for decades in a glass jar? Has he been whiling away the years working on a universal theory of relativity all this time? What would a brain completely devoid of sensory input do? Experiences with people put in isolation chambers suggest that they would start to hallucinate and dream. Perhaps you the reader are floating in a jar, and this article is your own invention, your brain’s way of telling you that all of what you see is just an illusion.
Imagine if we could learn to contact and communicate with the brains of the dead? Perhaps they could unlock secrets for us, even solve their murders by telling us who did it, or allow us to eventually re-animate them completely. Perhaps this will lead to a new service offered by funeral homes: preserving the brains of your loved ones and hooking them up to virtual reality so they can continue to enjoy their afterlife.
Of course, our meddling with the processes of death might just unleash a zombie apocalypse.