Newness Factor Weighs in on Brain

June 25, 2008— -- When Perry's Ice Cream changed its wrapping from the standard brick shape to the two-piece "sqround" package, was the new look enough for you to make the purchase?

Or did Kraft's addition of a flip-top cap to its salad dressings steer you away from your usual brand?

If so, you're not alone.

Humans may be wired to seek out new experiences, according to a study published Wednesday in the online edition of the journal Neuron.

The allure of novelty may be enough to make us look beyond our old favorites, "even in a situation where we don't have any good reason to expect something to be better than before," says Bianca Wittmann, lead author of the study and postdoctoral researcher at University College London.

In the study, researchers allowed 15 adults to select from a series of four black-and-white pictures. Each image was assigned a probability that selecting it would result in a monetary reward — one British pound. The participants were familiar with some but not all of the images.

"The pictures were stand-ins for slot machines," says Nathaniel Daw, co-author of the study and assistant professor of neuroscience and psychology at New York University.

People took a gamble when picking the pictures. After seeing the pictures multiple times, though, they could figure out which ones gave them the highest probability of cashing in.

As a twist, researchers periodically swapped pictures out, often replacing them with an unfamiliar image.

"What we found is that people preferentially go for the ones they've never seen before," Wittmann says. Rather than stick with the familiar — a picture for which they've already figured out the probability of getting money — they'd rather take their chance on a new picture.

"[This study] helps make sense of the fact that novel situations are not neutral to us. We tend to like them," says Dr. David Spiegel, professor and associate chair of psychiatry at Stanford University School of Medicine.

During the study, Wittmann and her colleagues looked at people's brain activity through functional magnetic resonance imaging (fMRI), which tracks blood flow. Increased blood flow in a particular area of the brain shows that it is engaged.

When people chose new images, Wittmann says that an area deep in the brain called the ventral striatum lit up on the fMRI scans. The ventral striatum is thought to be involved in emotions and behavior, including addictions.

"When people shoot up stimulant drugs like cocaine, they tend to trigger activity in this system," Spiegel says.

When activated, nerve cells in the ventral striatum release a chemical called dopamine, which stimulates feelings of enjoyment and pleasure.

Even for the average person, not just people who use drugs, Wittmann says that the emotions brought about by the release of dopamine are "a large part of what keeps us going and what makes us get up in the morning"; they are our internal reward system for certain behaviors.

It may be these feel-good sensations that caused the participants to keep selecting the new images.

"They treated these novel images as if they were worth more money than they actually were," Wittmann says.

In certain situations, it may be beneficial for humans to go out on a limb and break from habit.