Neuroscientists Diagnose the Brain Condition of Pop Culture Zombies
Following the success of works like The Walking Dead, 28 Days Later, and World War Z, zombies have seen something of a renaissance in popular culture. But modern versions of zombies are often short on explanations for the zombie apocalypse, and especially the "hard science" behind the devastating disease of zombism. Now, in their new book, "Do Zombies Dream of Undead Sheep? A Neuroscientific View of the Zombie Brain," two neuroscientists from Carnegie Mellon have provided a much-needed "tongue-in-cheek analysis of... the puzzle of what has happened to the zombie brain to make the undead act differently than their human prey."
In their introduction to the book, authors Timothy Verstynen and Bradley Voytek write, "Even if you've never seen a zombie movie or television show, you could identify an undead ghoul if you saw one. With their endless wandering, lumbering gait, insatiable hunger, antisocial behavior, and apparently memory-less existence, zombies are the walking nightmares of our deepest fears. What do these characteristic behaviors reveal about the inner workings of the zombie mind? Could we diagnose zombism as a neurological condition by studying their behavior?"
In their extensive analysis, the scientists identify all of the distinctive behaviors of zombies in popular culture, and then draw neuroscientific conclusions based on which parts of the brain control those behaviors. They come to the overall conclusion that all of the walking dead have a hypothetical neurological condition called Consciousness Deficit Hypoactivity Disorder, or CDHD: "Conscious Deficit Hypoactivity Disorder [is a condition characterized by] the loss of rational, voluntary and conscious behavior replaced by delusional/impulsive aggression, stimulus-driven attention, the inability to coordinate motor-linguistic behaviors and an insatiable appetite for human flesh."
But what causes this condition from a neurological perspective? Verstynen and Voytek assert that damage must be sustained to specific parts of the brain in order to induce zombies' characteristic behaviors. For example, the inability to recognize human faces is caused by damage to the fusiform gyrus, and damage to the superior temporal gyrus can cause their emotional detachment and anti-social behavior. Their difficulty understanding speech or using language themselves could be caused by trauma to either the temporal parietal junction or Broca's area in the frontal lobe.
The primary potential obstacle to creating some kind of unified theory of zombism is that some of the "zombies" in zombie films or television shows aren't "undead" at all, they are simply living people who display similar behaviors (28 Days Later is a fitting example, as it is technically a "pandemic movie" rather than a "zombie movie").
"In the whole supernatural 'living dead' theory, zombies are characterized primarily by their highly abnormal but stereotyped behaviors. This is particularly true in more modern manifestations of the zombie genre wherein zombies are portrayed not as the reanimated dead, but rather as living humans infected by biological pathogens. They are alive, but they are certainly not like us."
In order to account for the differences between these two types of zombies, Verstynen and Voytek came up with two subtypes of CDHD; zombies with CDHD-1 are the classical undead zombies that are slow-moving and have essentially no mental faculties, like on The Walking Dead, while zombies afflicted with CDHD-2 are fast-moving and have more of their wits about them.
"In conclusion," they write, "the series of brain changes seen in CDHD reflect a loss in so-called 'higher order' cognition areas and the neocortex the CDHD-1 subtype also reflects a degeneration of the cerebellum."