Giving to Duke


Four ways our brains have evolved to help us make better decisions

April 30, 2014

Why do you get stuck in a mental rut? Is regret necessarily a bad thing? What is your brain’s chief motivator?

Michael Platt’s research on how the brain makes decisions in uncertain and socially complex environments has led to some surprising findings related to these questions.

“Our research shows that our brains are extremely well-adapted to finding rewards, overcoming uncertainty, exploring new options despite the risks, learning from regret, and dealing with others,” said Platt, director of the Duke Institute for Brain Sciences (DIBS) and professor of neurobiology.

“In fact, the human brain looks like an optimal toolkit for navigating a dynamic, physically-challenging and socially complex world.”

Platt and other DIBS faculty and students will lead a session at Duke Forward in Philadelphia on May 16 on the connections between body, brain, and mind.

Here, Platt shares four ways the brain has evolved to cope with our environments—and how that may ultimately help us make better decisions.

1. Our brains are wired for reward.

Human, monkey, bird, or butterfly. All animals need food, water, and shelter, and most need to find mates. When we seek and obtain these vital resources we experience “reward.”

Not surprisingly, our brains are wired to find rewards and to identify the cues that predict them. It’s well-known that certain brain circuits—especially those associated with the chemicals dopamine and serotonin—drive us to seek rewards. Yet it’s also becoming increasingly clear that, actually, almost every part of the brain is sensitive to reward.

How we perceive the world, what we learn and remember, and how we act all depend on our expectations for reward. And the brain areas and circuits that let us perceive, learn, remember, and move collectively drive us towards rewards and away from punishment.

When these mechanisms fail, we may suffer disruptions in our ability to see what’s rewarding, learn or remember what was rewarding in the past, or act appropriately. For example, people with disorders that affect dopamine or serotonin signaling like Parkinson’s disease and depression often have trouble learning what rewards and motivates behavior.

2. Our brains drive us to explore.

Rewards are terrific for getting us to repeat behaviors. Unfortunately, rewards can also keep us stuck in a rut, unable to branch out and explore new alternatives.

Recent work from our lab and others has shown that there are circuits in our brains that drive us to explore by overcoming the seduction of a small but sure reward. What’s really interesting is that these circuits are particularly responsive when the environment is new and thus outcomes are unpredictable. Trying out new options may be risky, but doing so is the only way to learn about the value of the options confronting us.

In fact, the circuits we and others have identified as being important for exploration also seem critical for creativity and innovation because they are inhibited by performing rote, well-rehearsed actions.

Tip of the day: Neuroscience data shows that if you want to be creative you may need to stop focusing on the problem at hand and do a little day-dreaming.

3. Our brains use regret to make better future decisions.

We all tend to think that regret is a bad thing. It certainly feels bad, and we associate regret with failure.

Recent findings in neuroscience, however, show that regret is critical for learning about the environment. In particular, regret—and its more formal mathematical cousin counterfactual reasoning—help us to identify when we could have done better if we’d acted differently. It turns out that our brains, and the brains of other animals like monkeys, have specific areas devoted to identifying the outcomes of the actions we didn’t take.

Mathematical models show that regret and other counterfactual information are crucial for rapid learning and making better decisions in the future. Unfortunately, regret can also hijack the brain to change behavior even when the environment is completely random.

4. The default mode of our brains is social.

People are fundamentally social—and our brains reflect that. There are specific brain circuits that identify individuals around us, who they are, their states of mind, and possible intentions. These areas feed into others that assess the value of acting in different ways with regard to others around us.

Several brain areas appear to have evolved specifically to deal with other individuals. These areas allow us to empathize with them, guide cooperation, and learn from their experiences. Amazingly, other highly social animals like monkeys have the same specializations. Maybe there’s much more to the aphorism “monkey see, monkey do” than we previously realized!

Make a Gift

With your support, Duke will continue to tackle society's toughest challenges and improve lives worldwide.