When delusion triumphs over truth
New Scientist, 28 January 2006
BELIEF has never literally moved a mountain, but it can have some
dramatic effects. Take Madeleine Rizan. By the time she bathed in the
waters of Lourdes in 1858 she had been paralysed for 24 years, yet,
according to the record, she regained her ability to move. Then there
are the dozens of heart patients in the 1950s who were helped by a
procedure known as internal mammary ligation - which worked just as
well when patients simply believed it had been done. There are even
instances of women who stop menstruating, grow a round belly and begin
to lactate, in the firm but mistaken belief that they are pregnant.
Equally mysterious are the paralysed people who believe their limbs are
still working normally, despite the evidence of their own eyes.
is going on inside our brains when we believe? How does that trigger
physical changes in our bodies? And why would our minds believe the
world is a certain way in flat contradiction to the evidence of our own
senses? Or, put another way, what exactly is the biological basis of
belief? "It's a fascinating question and poorly studied," says
Vilayanur Ramachandran, a neurologist at the University of California
at San Diego who has spent much of his career studying "disorders of
belief". Dean Hamer, from the US National Institutes of Health in
Bethesda, Maryland, and author of The God Gene, goes further. "We have
absolutely no idea," he says. "Nobody has any idea."
moments, even Hamer would admit the picture is not quite as grim as
that. There seem to be at least two lines of thinking on the matter.
One is that belief in the widest sense is primarily a product of
rationality and reasoning. In order to believe in something, you have
to know vaguely what it is and how it will play out. The other is that
believing is more emotional - a sort of gut reaction. "That's why
people feel belief and don't think belief," says Hamer, who is inclined
towards the latter camp.
Getting a handle on the biological
basis of belief is not easy. It is extremely difficult to study how
faith in God's power to heal can actually heal, for instance. Luckily,
there is an alternative. Faith in medicine is almost as ubiquitous as
faith in God, and the effects are far easier to control and to measure.
We know, for instance, that about 80 per cent of the effect of
antidepressants derives from people's faith that they will work
(Prevention & Treatment, vol 5, p 23). The influence of belief may
be even stronger in alternative medicine. A study out last September
showed that acupuncture seems to alleviate headaches no matter where in
the body you stick the needles or how you twiddle them (British Medical
Journal, vol 331, p 376). And countless medical studies have used
placebos to show that belief is a major player in the healing process.
"The best way to understand the scientific effect of belief is to look
at the literature on the placebo effect," says Herbert Benson, director
of the Mind/Body Medical Institute in Boston.
Put simply, the
placebo effect is the biological impact of believing in a medical
treatment. There is no doubt that it is a real and powerful force. The
question is, how exactly does it work. Last year, Jon-Kar Zubieta at
the University of Michigan at Ann Arbor published research that tackled
the issue head-on. He gave 14 healthy men infusions to make their jaws
ache. They were then given a treatment that they were told "may or may
not relieve pain". In fact, it was only a saline solution, yet all the
men reported less pain. And their pain relief was not just subjective.
Using positron emission tomography, or PET, to scan their brains,
Zubieta found that volunteers produced more endorphins, the body's own
natural opioid painkillers, after receiving the placebo (Nature
Neuroscience, vol 25, p 7754).
his data for clues as to what was going on, Zubieta found differences
in the way untreated pain and placebo-treated pain affected the brain.
With the placebo, not only did people release more endorphins overall,
they also released them in additional areas of the brain. These
included regions involved in higher-order cognition such as parts of
the rostral anterior cingulate, which helps determine how much pain you
are feeling, the insular cortex, which receives signals from the body
about pain, and the nucleus accumbens, which tells you how important it
is. Zubieta also found differences between people who said in advance
that they expected to get a lot of relief and those who were more
sceptical. In the faithful, he found more endorphins were released in
the dorsolateral prefrontal cortex, a cognitive area thought to be
involved in decision making, interpretation and selective attention.
this suggests that the cognitive experience of anticipating relief
plays a major role in allowing it to happen. In other words, the
evidence supports the hypothesis that belief is a conscious, rational
process - a kissing cousin to expectation. And further evidence from
behavioural studies seems to bolster this. First and foremost is the
fact that to benefit, you have to know you are being treated - the
placebo effect won't kick in if a sham medication is given covertly.
Similarly, praying for yourself or knowing that family and friends are
praying for you seems to produce some positive results, while being
secretly prayed for does not (The Lancet, vol 366, p 211).
also appears to be critical. That makes sense, as you have to derive
your expectations from somewhere. A study in people with Parkinson's
disease, for example, found that after taking a placebo people actually
secreted dopamine, the very neurotransmitter they are short on, and at
levels similar to that produced by drugs (Science, vol 293, p 1164).
But all these patients had previously had positive experiences taking
medicines. This is true for many of us. People with a long history of
not being helped by conventional medicine, such as those with chronic
pain, do not respond well to conventional placebos either. Nor do
people with Alzheimer's disease, whose memory impairments or cognitive
decline may make it hard to develop the kind of expectations that
placebos might depend on. Likewise, children who have no preconception
of a particular procedure such as acupuncture get no relief from it.
it is not so surprising that expectation and experience are bound up
with the placebo effect, which by its very nature is all about the
belief that a treatment will or will not work. But underlying this
effect is a more stable set of beliefs in the power of medicine in
general. There's a direct parallel with other basic beliefs such as
religious belief and belief in the evidence of our senses. Myriad such
beliefs form the foundations of the way we see the world, and they tend
to be very stable. We would be basket cases if every bit of conflicting
evidence caused us to alter our world view. Imagine, for example, that
you have slept in an awkward position and wake up with no feeling in
your arm. You don't immediately assume that you are paralysed.
sometimes we are forced to reassess our deep-held beliefs, and in some
cases resistance to change can cause medical oddities. It is these
strange conditions that Ramachandran studies to get an insight into the
nature of belief.
Imagined experiencesAmong the
patients he has observed are a group with a condition known as
anosognosia, usually caused by stroke. These people deny facts about
their bodies, such as that they are paralysed. They will stare at an
immobile arm, for example, while insisting they are throwing a ball
with it. Ramachandran recalls one case in which he managed to get a
woman in denial about the fact that her arm was paralysed to briefly
admit it. He did this by providing her with an acceptable way to
believe: he told her that he was injecting her arm with an anaesthetic
and that it would be temporarily paralysed. After he injected her with
a saline solution she did indeed notice that her arm couldn't move. To
rule out mere suggestibility, he injected the other arm too, whereupon
she complained that the anaesthetic wasn't working.
has studied many such patients. Not all are as resolute as this one.
Most anosognosics make excuses, explaining why they don't want to move
their paralysed limb - that they have arthritis, for instance, or that
the other doctors have already poked and prodded so much that they are
fed up. But he has noticed that only patients who have had damage to
the right side of their brain confabulate in this way. People with
left-side damage, by contrast, are acutely aware of their paralysis and
tend to talk about it non-stop.
Such observations have led
Ramachandran to suggest that in healthy brains there is a back and
forth between believing the old and accepting the new. The left
hemisphere, he maintains, tries to impose consistency, whereas the
right hemisphere plays devil's advocate, trying to get us to question
our beliefs in the light of new evidence. In people with anosognosia,
he suspects that brain damage caused by the stroke somehow impairs the
right hemisphere's natural scepticism. The left hemisphere is left on
its own to uphold the status quo no matter what - even at the risk of
Much more common examples of such disorders
of belief, he suspects, are illnesses such as anorexia and bipolar
disorder. People who have anorexia can be completely emaciated yet
still look in the mirror and see themselves as fat. In bipolar
disorder, the mania phase is often characterised by grandiose and
apparently unchecked beliefs. The depressive phase is the opposite, a
collapse of self-belief. It is generally accepted that these illnesses
disrupt the emotions, so Ramachandran's suggestion that they also have
to do with impaired belief systems chimes with the second hypothesis
about belief - that it is emotional and akin to longing.
has raised this idea, arguing that belief - be it in God, medicine or
whatever - slightly alters our emotional state. Just as feeling joy has
chemical consequences in the brain, so, he speculates, does feeling
faith. "Belief," he suggests, "is changing the tenor of the brain."
Hamer thinks that belief is mediated by the same neurotransmitters -
for example, dopamine and serotonin - that mediate other emotions. He
has found, for instance, that there is a variant of a gene called VMAT2
that may be associated with greater spirituality. The VMAT2 protein
seems to control the flow in the brain of monoamines, a class of
neurotransmitters that includes serotonin and dopamine.
Zubieta's study also indicates a role for emotions. One of his most
intriguing findings was that the more people suffered from the pain he
induced, the more placebo effect they got. In other words, the greater
their longing for relief, the more the endorphins flowed. Zubieta's
working hypothesis is that placebos piggyback on the brain's innate
painkilling ability, so believing that a treatment will bring relief
merely engages this natural system more fully.
Perhaps belief is
both a rational process and an emotional one. The picture is still very
hazy but, at the very least, attempts to discover the biological
underpinnings of belief highlight the fact that it is real: it does
have measurable physical effects in our brains. More intriguingly,
these effects have the potential to influence the outcome of events.
This may even go some way towards explaining the role that self-belief
has in helping us achieve our goals in life. If belief in our own
abilities can actually bring success, then belief becomes a virtuous
circle, a self-fulfilling prophesy. No wonder people are often so often
so eager to believe in the first place.