Published online 24 October 2007 | Nature | doi:10.1038/news.2007.191

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Optimism brain regions identified

Researchers home in on brain areas that light up for a bright future.

I'm dreaming of a bright future...GETTY

Neuroscientists have pinpointed the areas of the brain that help us to look on the bright side.

People have a propensity to be optimistic, expecting to live longer and be healthier than the population average1. Knowing which regions of the brain are affected should help us understand this tendency. It could also assist in unpicking the mechanisms of depression, which is related to pessimism and affects the same network of brain regions.

Elizabeth Phelps and her colleagues from New York University ran into this so-called ‘optimism bias’ when they set out to investigate what happens when people imagine emotional events in the past and future.

They had volunteers think about events such as winning an award, or the end of a romantic relationship, and at the same time they scanned their brains using functional magnetic resonance imaging.

But the researchers hit on a problem. The volunteers were not good at imagining bad things happening to them. They would even turn relatively neutral events, such as getting a haircut, into positive things. “It was very hard to get people to imagine negative events in the future,” says Phelps. So the team changed their focus: they decided to look at the brain areas involved in the optimism bias instead.

Imagine that

The group asked people to imagine positive and negative events that had either happened in the past or might happen in the future. Then, the volunteers rated their levels of optimism (as a general personality trait) using a standard psychological test.

Imagining positive events in the future was accompanied by activity in two areas of the brain that usually regulate how emotion affects memory and decisions: the amygdala, buried deep within the brain, and the front portion of the anterior cingulate cortex (ACC), which sits just behind the eyes. Conversely, activation in both these areas dropped below average when the volunteers thought about future negative events.

The more optimistic people considered themselves to be, the greater the activity in the ACC. The results are published in Nature2.

That the ACC is involved makes sense to Phelps, since it fits with previous research. “When you’re in a positive mindset you’ll see more activity in this region," she notes. More generally, Phelps suggests, the ACC could be acting as a central hub for signals from other parts of the brain that feed into how we feel about events. "We think this is a general regulatory region that may be mediating this tendency we have to think about things optimistically.”

High emotion

The study meshes nicely with other work on the brain networks that deal with remembering the past and imagining the future. Dan Schacter’s group at Harvard University in Cambridge, Massachusetts, have been studying these processes as people recall non-emotional events, and has found very similar regions at work3. “This is a nice complement to the kind of stuff we’ve been doing,” he says.

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“The interesting link here is with the ACC — that’s a region where depressed patients show a decrease in activity,” he says. People with depression are more pessimistic and find it hard to imagine future events in a positive light.

Phelps agrees that these results might provide insight into the mechanisms that underlie depression. But how that might affect future treatments is unclear. 

  • References

    1. Weinstein, N. D. J. Pers. Soc. Psychol. 39, 806-820 (1980).
    2. Sharot, T., Riccardi, A. M., Raio, C. M. & Phelps, E. A. Nature 450, 102-105 (2007).
    3. Addis, D. R., Wong, A. T. & Schacter, D. L. Neuropsychologia 45, 1363-1377 (2007). | Article | PubMed | ISI |
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