In Night of the Living Dead, zombies are brought back from the dead by a "mysterious force" that allows their brains to continue functioning. But how exactly does a zombie brain function? Finally, a Harvard psychiatrist has the answers.

Schlozman concludes that zombies possess just enough frontal lobe activity to "listen" to the thalamus, through which sensory input is processed.

Absent a properly functioning frontal lobe, a zombie is driven entirely by base emotions - such as rage - that are housed in the primitive parts of our brain, notably the amygdala.

A zombie would have a dysfunctional anterior cingulate cortex, rendering it unable to modulate feelings of anger. The result? Hyper-aggression.

Clearly, zombies suffer from cerebellar and basal ganglia dysfunction (duh!). Those are the parts of the brain that make fluidity of motion possible.