Researchers say they've found one reason optimists
retain a positive outlook even in the face of evidence to the contrary.
A
Nature Neuroscience study suggests the brain is very good at processing good news about the future. However, in some people, anything negative is practically ignored - with them retaining a positive world view.
The authors, scientists at University College London said optimism did have important health benefits. About 80% of
people were optimists, even if they would not label themselves as such.
There is a very fundamental bias in the brain”
~ Dr Tali Sharot
University College London
They rated 14 people for their level of optimism and tested them in a brain scanner. Each was asked how likely 80 different "bad events" - including a divorce or having cancer - were to happen. They were then told how likely this was in reality. At the
end of the session, the participants were asked to rate the
probabilities again.
There was a marked difference in the updated scores of optimists depending on whether the reality was good or bad news.
Dr Sharot gave the example of the risk of cancer being set at 30%.
If the patient thought their risk was 40%, then at the end of
the experiment they downgraded their own risk to about 31%, she said.
However, if the patient originally thought their risk was
10%, they only marginally increased their risk - they "leaned a little
bit, but not a lot".
Pick and choose
When the news was positive, all people had more activity in
the brain's frontal lobes, which are associated with processing errors.
With negative information, the most optimistic people had the least
activity in the frontal lobes, while the least optimistic had the most.
The report suggests the brain is picking and choosing which evidence to listen to. Dr Sharot said: "'Smoking Kills' messages don't work as people
think their chances of cancer are low. The divorce rate is 50%, but
people don't think it's the same for them. There is a very fundamental
bias in the brain."
Dr Chris Chambers, neuroscientist from the University of
Cardiff, said: "It's very cool, a very elegant piece of work and
fascinating. For me, this work highlights something that is becoming
increasingly apparent in neuroscience, that a major part of brain
function in decision-making is the testing of predictions against
reality - in essence all people are 'scientists'. And despite how sophisticated these neural networks are, it
is illuminating to see how the brain sometimes comes up with wrong and
overly optimistic answers despite the evidence."
Optimism seem to be good for your health. A study on nearly
100,000 women showed a lower risk of heart disease and death in
optimists.
But as Dr Sharot points out: "The negative aspect is that we underestimate risks."
Ian: And they worked all that out from just 14 people? Hmm. Isn't it a bit obvious? Did it really need a study?
in the production of diuretic alkalosis has been established (Kassirer et al, 1965).
Cassie found this amazing article here. It's amazing because he is saying what we've been saying for ages. Of course no-one listens to us because we aren't heart surgeons! 
Seeing the milky blue
water tumbling over pale cream rocks as it makes its way from high
mountain to orchard, you can’t help but see that this is mineral
rich, alkaline water. Seeing the rich grasses growing between the rows
of espaliered apple trees you understand that there really is a balance
here. The soil is rich beyond belief and so the trees, the vegetables,
and the people share that balance. Wildflowers are still growing
everywhere here and it’s not spring, it’s autumn. Roses are everywhere,
lavender, and all manner of decorative trees. 
