The young woman went to doctors to have them probe her brain, to root out where her seizures came from. But unexpectedly, their investigations and the procedure they performed led her to experience the creepy illusion of a person standing behind her, where nobody was actually present. The patient described the illusory person as young and of indeterminate sex, a "shadow" who did not speak or move. "He is behind me, almost at my body, but I do not feel it," she reported.

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