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?