The term “walker brain” originates from the television show The Walking Dead as an explanation for the behavior of the reanimated dead, known as walkers. This concept frames their actions as being driven by a biological process, not supernatural forces. The show’s science centers on a pathogen’s effects on the human brain after death, establishing how walkers function and can be stopped.
The Reanimation Process
The transformation into a walker is caused by the “Wildfire Virus.” According to Dr. Edwin Jenner at the Centers for Disease Control and Prevention (CDC), this pathogen is dormant within every living human. It does not cause the initial death but becomes active once a person dies from any cause, initiating a reanimation process that targets the central nervous system.
Upon death, the Wildfire Virus restarts only the brainstem. This event brings the body back to a state of animation without restoring consciousness or higher-order thinking. Reanimation times can vary, with some individuals turning in minutes, creating a shell of a person driven by the most primitive parts of the brain.
Surviving Brain Functions
Once reanimation is complete, the walker brain is fundamentally different from a living human brain. The cerebrum, which houses personality, memory, and reasoning, remains inactive. This explains why walkers do not recognize loved ones or show any semblance of their former selves, leaving only a body operating on a primal level.
The brainstem is the only functional part of the walker’s brain. This region controls basic motor functions, resulting in their characteristic unsteady, shuffling gait. It also governs instinctual behaviors, primarily the relentless drive to feed. All actions are reduced to simple, repetitive responses to external stimuli like sound and movement.
The Kill Method Explained
The method for neutralizing a walker is directly linked to its physiology. Since the brainstem is the sole operational center, it is the only part of the body that, when destroyed, will terminate its function. Injuries to other areas, even those fatal to a living person, are ineffective as a walker will continue to move despite extensive bodily harm.
Therefore, the only definitive way to stop a walker is to destroy or sever the brainstem. This is why the “kill shot” to the head is the primary survival tactic. By piercing the skull and obliterating the brainstem, the connection that animates the body is permanently broken. This biological fact dictates the rules of engagement for survivors.