Brain study shows the waiting is the hardest part

By Amy Norton

NEW YORK (Reuters Health) – Anyone who has ever waited in
dread to have a root canal may find some comfort in the
findings of a new brain-imaging study.

For some people, researchers say, the waiting is indeed the
hardest part, and finding a distraction might help.

Their study, published in the journal Science, used a
brain-imaging technique called functional MRI to investigate
the neural mechanisms underlying dread — specifically the
agony of waiting to have a painful procedure.

It found that among 32 volunteers who agreed to have a
series of shocks to the foot, some of them dreaded each shock
so much that they repeatedly opted to have a higher-voltage
jolt just so they could get it over with more quickly.

These individuals, dubbed “extreme dreaders,” showed
greater activity in a brain region related to both pain and
attention. The findings, say the researchers, indicate that
dread arises not from simple fear, but from the brain’s
attention to the unpleasant event.

“The dread is often worse than the event itself,” said lead
study author Dr. Gregory S. Berns, a professor of psychiatry
and behavioral sciences at Emory University School of Medicine
in Atlanta.

The brain-imaging results are “good news,” he told Reuters
Health, because they indicate that extreme dreaders can do
something to alleviate the problem: find a distraction – such
as meditation, exercise or some other activity — to take the
focus off the anticipated event.

For the study, Berns and his colleagues took brain images
of volunteers who agreed to endure electrical shocks to their
feet. First, each jolt was preceded by a cue that told
participants how intense it would be — 60 percent of their
maximum pain tolerance, for instance — and how long they would
have to wait for it.

In a second go-around, participants were presented with
choices on how each shock should be delivered, with the voltage
and timing of the jolt as the variables. For example, they
could choose between having a shock at 90 percent of their
maximum pain tolerance delivered in the next 3 seconds, or one
at 60 percent intensity in 27 seconds.

Of the 32 volunteers, nine — the extreme dreaders —
consistently opted for the stronger shock in order to avoid the
longer wait.

This may seem illogical to many people, Berns said, but for
extreme dreaders avoiding the anguished wait makes sense.

And it was the extreme dreaders who showed particularly
high activity in the brain’s so-called pain matrix during the
build-up to their electrical shocks — specifically, in areas
related to attention, but not those associated with fear and
anxiety.

In other words, extreme dreaders were giving more attention
to their foot than “mild dreaders” were.

So finding a distraction may be the best way for extreme
dreaders to deal with the wait for a medical procedure, Berns
said. This, he noted, is something many people have
“subjectively” known, but the new findings reveal the brain
basis for it.

SOURCE: Science, May 5, 2006.