That structure, in turn, is tightly linked to the orbitofrontal cortex, which has been shown to be activated by monetary rewards.

ECONOMIST: Evolutionary biology

They showed part of the brain thought to be involved in "food appeal", the orbitofrontal cortex, became more active on an empty stomach.

BBC: Skipping breakfast primes the brain to seek out fat

Dr. Voytek has examined the the aggression of zombies, and notes that the most likely explanation for this behavior is a lack of a functioning orbitofrontal cortex.

FORBES: Explaining the Neuroscience of the Zombie Epidemic