Why optimism is good for you, especially when young:

"MRI study suggests novelty is its own reward
By John Timmer | Published: June 30, 2008 - 08:28AM CT

Humans frequently face a straightforward dilemma: stick with something that has a known benefit or try something new and face the unknown. The ability to choose novelty over a known quantity can help us find new and more rewarding experiences, and it adds a wildcard to human behavior. An open access study published in the journal Neuron looks into how the brain processes decisions between options with unknown and expected outcomes, and it finds that the brain responds to the unknown in the same way that it anticipates a positive outcome.

Clearly, exploring novel options is a necessity, since otherwise people would never be able to optimize their behavior. The authors discuss how behavioral models performed on computers have attempted to approximate this through a mathematical analysis of past instances where an unknown was chosen—apparently, this becomes computationally expensive once the number of instances gets large. Instead, many models simply perform an approximation where the novel choice is given a slight positive value, which approximates real behavior quite well. So well, in fact, that the authors decided to test whether this is actually the way the brain operates.

To do so, they set up a test where subjects were asked to choose one of four pictures displayed at the same time. Each one of those was assigned a permanent reward frequency; whenever it was picked, it had a set probability of winning the subject £1. Each image would appear an average of 20 times in succession, allowing the subject a chance of getting a feel for its odds. Whenever an image was dropped, a new one would replace it with its own distinct odds of rewards. Over extensive repetitions, the test offered the subjects many chances to choose a novel photo or stick with a known risk. The subjects also underwent functional MRI imaging in order to examine the regions of the brain that were active during the test.


With the statistics in hand, the authors sought to figure out the parameters that gave the best approximation of the test subjects' behavior and found that people do appear to assign a value to novel picture options. Given the fact that a successful choice was worth £1, researchers could actually calculate a price for the value of novelty: four pence.

In the brain, neural activity associated with a novel choice occurred in an area identical to that activated when a known image triggered the expectation of a positive result. In essence, the test subjects chose novelty because their brains—specifically, the right ventral striatum—interpreted it in a manner similar to a known positive result.

To confirm that this was specific to novelty, the authors determined that the degree of activity in specific test subjects correlated with the frequency that they choose a previously unknown image. The activity also correlated with novelty-seeking behavior when the subjects filled out a personality survey. Overall, the researchers build a pretty compelling case that people try the new in part because they view a novel choice as its own reward.

In their discussion, the authors note that there are limits to this behavior. Nearly any animal humans have tested will learn to avoid novelty if it is frequently associated with negative outcomes. The discussion also points out that novelty seeking may not always be rewarding, as it can be associated with substance abuse. Still, behavior indicates that novelty is prized in a variety of animals, suggesting it's an old evolutionary adaptation and therefore a major influence on human development. " (Ars Technica)