Neurologist Olaf Blanke of the Brain Mind Institute in Lausanne, Switzerland, and his colleagues, were attempting to identify the source of epileptic seizures in a 23-year-old woman. They applied a mild current through surgically implanted electrodes to various regions of her brain. Not much happened until the researchers stimulated the woman's left TPJ, located roughly above the left ear. Suddenly, she reported feeling the presence of a mystery person behind her, a motionless and speechless shadow that imitated her body posture and actions. "He" lay beneath her when she lay down, sat behind her when she sat down, and attempted to take a test card from her when she tried to participate in a language exercise.
Such delusions are similar to those seen in patients with schizophrenia, says Blanke. Schizophrenics often mistake their own bodies to be someone else's, for example, and attribute their own actions to others. They also have frequent illusions of being followed, or controlled by a stranger, as do those who claim to have been manipulated by aliens.
