From the BBC's "Tomorrow's World"
WEDNESDAY 15th December 1999
For the first time, a patient with multiple
personality disorder has been monitored using an
MRI scanner while switching characters. The
scans showed marked changes taking place in her
brain. Intriguingly the hippocampus, an area
associated with long-term memory, switches off
during the change to an alter ego and is
reactivated on the switch back.
Multiple personality disorder (MPD) is a
controversial area of mental health. It has been
met with scepticism from some psychiatrists who
feel the condition isn't genuine. Others say
that while it's very rare, MPD is certainly real
and usually stems from childhood trauma and
abuse. They say the extra personalities are
brought into being by the patient to protect
themselves from the reality of their situation.
Carrying out tests like this has been difficult
for two reasons. First, functional MRI's which
can measure brain activity are only a recent
innovation, and second finding a patient who can
switch personality on demand while in a scanner
is very unusual. The psychiatrists involved in
the experiment say more work is needed to draw
any general conclusions. Nevertheless, it
provides some evidence that there may be a
physiological basis to the condition.