Creepy
Experiment exposes Paranoia and Sense of Alien Control
By Charles
Q. Choi
Special to LiveScience
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.
When the patient sat and embraced her knees with
her arms, she noted the "man" was now
also sitting and clasping her in his arms, which
she described as unpleasant. When asked to read
a card in her right hand, she noted the shadow tried
to interfere, saying, "he wants to take the
card" and "he doesn't want me to read."
Researchers said today that what they learned from
this woman, who is not named in their scientific
paper, could help shed light on psychiatric
effects, such as feelings of alien
control and persecution.
Cognitive neuroscientist Olaf Blanke at the Swiss
Federal Institute of Technology in Lausanne in Switzerland
and his colleagues investigated the 22-year-old
woman, who had no history of psychiatric illness.
They were evaluating her for surgical treatment
of epilepsy, and had implanted electrodes in her
brain
to study where her seizures originated.
The researchers found stimulating a region known
as the left temporoparietal junction caused the
woman to feel the presence of a shadowy person.
The temporoparietal junction is involved in distinguishing
self from other and integrating body-related
sensory information. Since the shadowy person closely
mimicked the woman, the researchers propose she
was experiencing an illusion based on her own body.
This effect is a symptom of schizophrenia,
and the scientists noted hyperactivity in the temporoparietal
cortex of schizophrenics could lead to include the
sensation that one's actions are being performed
by someone else.
"Larger studies are needed," Blanke told
LiveScience. "We reported findings in a single
patient."
Blanke and his colleagues report their findings
in the Sept. 21 issue of the journal Nature.
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