Zombies. It seems that one cannot be exposed to media for any substantial length of time without encountering the notion of undead beings rising up and destroying us all in a much-speculated zombie apocalypse. This sparks the question: is this possible in real life? Obviously, reanimating human beings is impossible with our technology, so the coming-back-from-the-dead-and-eating-you type of zombie is out of the question. However, a virus spread by human saliva or bodily fluid that targets certain parts of the brain in order to produce certain zombie-esque behaviors is theoretically extremely possible, and could potentially cause a worldwide zombie pandemic.
In order to figure out which parts of the brain to target, one must discern characteristics of the zombie that differ from regular humans. Zombies generally have little to no impulse/emotional control, are extremely violent, have memory loss, are clumsy and slow, and do not feel pain or empathy. The impulsiveness and violence indicate a damaged frontal lobe. The frontal lobe is the part of the brain that handles voluntary muscle movement, logic, intelligence, and other higher-order functions that differentiate humans and beasts. The memory loss represents damage to the hippocampus, the part of your brain that controls memory processing. The lack of grace and coordination in zombies, called ataxia, is due to a significantly damaged cerebellum and parietal cortex. And the lack of conscience or empathy is a result of a dysfunctional amygdala, the part of your brain that deals with processing emotions.
After being infected by this virus, presumably by saliva, a person would eventually exhibit full fledged “zombie-itis.” Numerous parts of one’s brain would decay, leaving a violent, clumsy, senile human being with the desire to consume flesh without any regard to their previous interpersonal relationships.