Two neuroscientists have analyzed the portrayal of zombies in movies and popular culture and used the information to work out the patterns of brain abnormalities that could cause the zombie behavior of the undead.
In their book, Do Zombies Dream of Undead Sheep? A Neuroscientific View, neuroscientists and zombie enthusiasts Timothy Verstynen, assistant professor in the Department of Psychology at Carnegie Mellon University and Bradley Voytek, assistant professor of neuroscience at the University of California, San Diego, were table to use their expertise in neuroscience to conduct what they described as a hypothetical “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.”
They were able show how “zombiism” could be expressed in terms of current scientific knowledge of how the brain functions. They provided a detailed analysis of the popular stereotypical traits of zombies that sheds light on the basic functions of the brain in its various states, and the different parts of the brain which control different cognitive and body functions.
Verstynen and Voytek developed hypothetical diagnostic criteria for the condition of “zombiism.” By creating a neuroscientific map of the zombie brain based on apparent cognitive defects exhibited by zombies in popular movies, such as 28 Days Later and Shaun of the Dead, the scientists hoped to be able to provide a detailed neuroscientific guide to surviving the looming zombie apocalypse.
“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 zombiism as a neurological condition by studying their behavior?”
The neuroscientists looked at such stereotypical zombie behavior as slow, shuffling movement, inability to understand and use language, memory loss, lack of motor skills, and gross anti-social behavior, such as eating people and drinking their blood, to propose specifications of brain disorders that could underlie zombie behavior.
They then grouped the set of symptoms under a hypothetical condition they called “Conscious Deficit Hypoactivity Disorder,” or CDHD, an acquired syndrome in which patients lose the ability to exercise conscious control over their own behavior.
“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.”
According to the scientists, there are two categories of CDHD zombies; CDHD-1 zombies and CDHD-2 zombies. The first category consists of slow-moving or shuffling zombies, such as seen in the movie The Walking Dead, and Shaun of the Dead, while faster moving zombies, such as in 28 Days Later and World War Z, could be categorized as CDHD-2, according to the Daily Mail.
“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.”
As a way to guiding the layman on a neuroscientific tour of the brain in terms of the popular conception of zombies and the undead, the scientists showed how damage to different parts of the brain could explain the different types of traits ascribed to zombies in popular movies and culture.
According to the scientists, damage to the fusiform gyrus could explain zombies’ inability to recognize human faces, while inability to interpret expressions and emotional detachment from human beings could be due to damage to the superior temporal gyrus.
Inability to understand language, difficulties in speech and communication could result from damage to the temporal parietal junction. Damage to the interior frontal cortex, including Broca’s area, could also cause speech difficulties.
Zombies’ poor memory and navigational skills could be due to damage to the hippocampus. Impulsive aggression and other antisocial behavior could be due to damage to the orbitofrontal cortex.
Damage to the dorsolateral prefrontal cortex could compromise decision making powers, while damage to the cingulate cortex could create conflict for zombies between eating people and developing emotional attachment to them; but ultimately, they would be unable to resist the urge to eat.
Damage to the parietal lobe could explain the apparent poor eyesight of CDHD-1 zombies in movies such as The Walking Dead. CDHD-2-type zombies would present with less damage to the cerebellum and the parietal lobe. But because both types of zombies show severe deficit in ability to plan ahead, both likely suffered extensive damage to the frontal lobes.
The scientists noted that extensive damage to different parts of the brain could still leave the primary sensory functions more or less intact, but zombies would not be able to respond with emotional or sensual attachment to these sensations.
“In conclusion, 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.”
They suggested that the pattern of brain damage in the undead could be attributed to stoppage of circulatory flow to the brain leading to oxygen and nutrient deprivation. CDHD-1 and CDHD-2 zombies are thus distinguished by the different areas or regions of the brain that were damaged due to nutrient and oxygen deprivation after death.
Infections and infestation of the brain could also produce changes in human behavior and cognition. For instance, tapeworm infestation and infection with a pathogen called Toxoplasma gondii through cats have noticeable neuropsychiatric effects.
The authors concluded that knowledge of neuroscience could be useful for fighting zombies. They, therefore, attempted to provide a neuroscientific guide to surviving the zombie apocalypse:
It is pointless trying to hurt zombies because they do not experience pain.
Zombies can be distracted very easily and can only concentrate on one active target. So if you want them to ignore you or simply walk past without harming you, hide and keep still.
Zombies are poor at distinguishing different aspects of reality. For instance, they cannot recognize faces. An easy way to get away from a group of the undead chasing after you is to mimic them. If you are good at mimicking zombies, you could walk through an entire army of zombies without them noticing you.
An obvious strategy for dealing with slow-moving zombies is to run as fast as you can.
Zombies don’t understand language, so there’s no point in trying to reason with them.
The fact that zombies don’t have memory functions means that they have difficulty finding their way in a big city. This gives people being pursued by zombies a great advantage.