Make Your Own Shadow Person

Is there an evil person following you around? No? Would you like there to be?

That's the effect that was created -- by accident -- when doctors applied electrical stimulation to theleft temporoparietal junction of a patient with epilepsy while evaluating her for brain surgery. It caused her to perceive the shadowy presence of a malevolent man right behind her, who mimicked her moves and tried to take things from her. It's among the effects that are observed in some patients with schizophrenia.

National Geographic reported that they put the woman through a series of tests to learn more about this unexpected result. When sitting at a table playing cards, the evil shadow man (whom she could not actually see) tried to take the cards before she could. When hugging her own knees, she reported that the man was hugging her. It was definitely creepy, and offers insight into how these electrical "short circuits" in the brain produce conditions such as schizophrenia and epilepsy.

It was not clear whether the effect would work on anyone, or whether this patient's epilepsy made her a special case.

Theleft temporoparietal junction is in a part of the brain normally associated with your sense of self. Disfunction in this region can produce out of body experiences, the impression that things you do are actually being done by somebody else, sensing the presence of imaginary people, and being controlled by external forces.