How would you like to take a virtual trip on the London
underground—the "tube"—to find out how paranoid you
Two hundred British citizens did just that, as part of a study by a
research group led by Daniel Freeman, Ph.D., a Wellcome Trust fellow at the
Institute of Psychiatry in London. The subjects were a representative sample
of the local population.
Each subject was required to wear a head-mounted, virtual-display device
that featured a high-resolution, 3-D view of a single train car compartment.
The animated travelers seen inside the compartment were computer-generated,
avatar-styled, human-like characters. The background noise heard consisted of
snippets of human conversation and the sound of a moving train.
After taking the same four-minute virtual tube trip between two stops, the
subjects were asked to report their experiences with the computer characters
they had encountered on the trip. Sixty percent reported positive or neutral
experiences, such as "One guy was checking me
out—flattering," or "It felt like a normal tube. People were
just trying to get where they wanted to go."
Forty percent of the subjects, though, reported negative experiences, such
as "There was a man who tried to stare me out" or "A lady
sitting down laughed at me when I walked past." In short, the latter
seemed to be thinking paranoid thoughts.
In fact all of the subjects had been assessed for trait
paranoia—paranoid thoughts in day-to-day life—before the virtual
trip, and subjects who reported such thoughts, the researchers learned, were
about twice as likely to experience paranoia during the virtual trip as were
subjects who reported no paranoid thoughts. This difference was highly
So it appears that about 40 percent of the general population experiences
paranoid thoughts at some time or at least under certain conditions, Freeman
and his colleagues reported in the April British Journal of
Freeman told Psychiatric News, "Traditionally, paranoid
thoughts have been thought of as a symptom of severe mental illnesses, such as
schizophrenia. This study clearly shows that paranoia is much more common than
Moreover, Freeman and his coworkers used their virtual-reality test to
identify some of the causes of paranoid thinking. They assessed their subjects
for worry, life stressors, social support, loneliness, and other psychological
factors before the subjects took the virtual tube trip. Then after the trip,
the researchers looked for links between any of those factors and experiencing
paranoia during the trip.
Such links did appear, they noted. Worry, subtle perceptual anomalies, and
inflexibility in thinking about how to deal with situations were significantly
linked with paranoia, and even when possibly confounding factors were
considered. "It is also of interest that women and those who regularly
used the London underground reported less paranoia," the researchers
But perhaps the greatest benefits to emerge from this study, the
researchers believe, are not their particular findings, but the broader
implications of what they have embarked upon. First, they pointed out,"
We have demonstrated that virtual reality is a safe and acceptable
method of studying paranoia in the laboratory." In other words, none of
the subjects reported any physical negative effects such as nausea, dizziness,
or blurred vision from the experience.
Second, they noted, studying paranoia with virtual reality has an advantage
over studying paranoia in the real world: computer characters can be
programmed to behave in ways deemed by consensus to be neutral. As a result,
researchers can be fairly confident that subjects' paranoid reactions are
truly paranoia, not suspicions based on real threats.
Thus virtual reality holds "great promise" for studying
paranoia, Freeman and his group concluded. For example, two or three different
virtual-reality settings could be used with the same subjects to see whether
they react with the same amounts of paranoia in each of those settings.
Virtual reality could be used to explore the impact of terrorism on paranoid
thinking in the general population or to compare paranoid reactions in the
general population with those in patients with persecutory delusions. Indeed,
virtual reality might even be incorporated into emerging cognitive-behavioral
therapy for paranoia.
An abstract of "Virtual Reality Study of Paranoid Thinking in
the General Population" is posted at<http://bjp.rcpsych.org/cgi/content/abstract/192/4/258>.▪