Ever wonder why zombies are after brains? Perhaps because their own brains don’t function as they should. Based on the clear cognitive deficits exhibited by zombies, UC Berkley neuroscientist Bradley Voytek and colleague Timothy Verstynen have modeled what their brains might look like.
All of the zombies’ “symptoms” would likely be caused by loss of the association areas of the brain, essentially ridding zombies of higher cognitive functions, as demonstrated by their overly-aggressive behavior and aphasia. Along with deficits of the association areas, the hippocampi would be massively damaged, resulting in memory defects. Finally, a loss of the majority of the cerebellum could explain their lack of coordinated movements. What would remain unimpaired, however, are most of the primary cortices. From so-called “behavioral observations”, Voytek and Verstynen concluded that vision, hearing, olfaction and gustation would still work perfectly, and somatosensation would be preserved for the most part. Since zombies are alive (or at least, undead) most parts of their thalami and midbrains, hindbrains, and spinal cords would be either over-active or preserved.
Many of these damaged regions of the zombie brain are part of the Papez circuit. James Papez identified the circuit while trying to understand the strong link between memory and emotion. He tested his hypothesis by injecting cats with a rabies virus to watch how it would spread. Sure enough, the disease spread through the hippocampus (important for memory formation), the orbitofrontal cortex (social cognition and self-control), the hypothalamus (hunger regulation, etc.), the amygdala (emotional regulation), and so on. Voytek even suggest that a virus similar to rabies could create zombies…maybe.
The widespread nature of zombie brain damage accounts for almost all of a zombie’s behaviors. It explains their over-active aggression circuit, global aphasia (they can’t speak or understand language), impaired pain perception, long term memory loss…With all this knowledge, we should be able to avoid the zombie apocalypse…right?
Zombies are terrifying creatures. The most panic-inducing aspect of their completely factual existence among us is that they have a taste for human blood and they will do anything to get to it. Recently, the Zombie Research Society (ZRS) has been attempting to scan (with some difficulty due to the fact that zombies aren’t huge fans of staying still in MRIs) and create a map of the zombie brain. A leading researcher in ZRS, Dr. Bradley Voytek, lectured about these terrors at Nerd Night SF. In his presentation he gives a medical term to describe the zombie condition: “consciousness deficit hypoactivity disorder (CDHD)- the loss of rational voluntary and conscious behavior replaced by delusional/impulsive aggression, stimulus-driven attention, and the inability to coordinate motor or linguistic behaviors.” So with those messy scans and some preliminary facts we know about the living dead, researchers such as Dr. Voytek have been able to come up with multiple images of what a real zombie brain must look like. More
You’re lying on a sandy beach on a hot sunny afternoon, enjoying a few hours of much needed laziness. As you open your eyes and confront the vastness of the ocean in front of you, light of 600nm wavelength hits your retina, kindling an impossibly long cascade of events in your brain: a molecule called retinal changes shape, neurons fire action potentials down the optic nerve, arrive at the lateral geniculate nucleus deep in the brain causing more action potentials in primary visual cortex in the back of your head, and so on ad infinitum. At some point, the mechanical wonder of 100 billion neurons working together produces something special: your experience of the color blue. What’s special is not that you can discriminate that color from others; nor that you are aware of it and paying attention to it. It is not notable that you can tell us about it, or assign a name to it. It’s that you have a subjective, qualitative experience of the color; there is something it is like to experience the color blue. Some philosophers call these experiences qualia – meaning “what kind” – but it is not important what kind of experience you are having, just that you are having one at all. Modern science hypothesizes that subjective experience is a product of the brain, but has no explanation for it. More