Ten seconds into the race, Lolo Jones had pulled far ahead of her competition at the women's 100-meter hurdles final during the 2008 Olympics in Beijing. What happened next was, for Jones fans, heartbreaking to watch. After effortlessly flying over eight hurdles, Jones clipped the ninth with her right heel, knocking it over and shaking her balance. Her rival, fellow American Dawn Harper, took home the gold medal. Jones placed seventh.

Crossing the finish line, Jones hung her head. A photographer captured her doubled over in tears, pounding the track with her fist.

Kai Pfaffenbach/Reuters

“I really just put too much pressure on myself," she later told Time.

That gets at one theory of choking: Scientists have long thought that the painful ooof moments are what happens when anxiety and tension cause people to over-think something that should come easily. Rumination, far from making movements more intentional, can sometimes make them clumsier.

"While it may seem counterintuitive, consciously trying to keep one's balance is likely to produce imbalance," said Juergen Beckmann, a sports psychologist from the Technical University of Munich, "as was seen in some sub-par performances by gymnasts during the Olympics in London."

But a new study published in The Journal of Neuroscience highlights yet another psychological process that might be unfolding when people choke. How you perform under pressure, the researchers found, depends on how afraid you are of losing what you have.

For the experiment, researchers from Johns Hopkins and the Kennedy Krieger Institute invited 26 participants to play a simple video game that involved moving some dots into a square using a computer cursor. The participants spent the first day learning the game, and then the game was modified to match each person's ability, so that it was equally difficult for each participant.

Then they tried to gauge how loss-averse the participants were by asking them to perform coin-toss gambles for varying amounts of money, such as, "If the toss of a coin would determine your chance of winning $4 or losing $2, would you take the gamble?"

"Most people value losses twice as much as gains," lead study author Vikram Chib, a biomedical engineering professor at Hopkins, told me. People who would only be willing to lose $5 if they stood to gain $100, for example, are extremely loss-averse.

Then, they asked the participants to play the game again, only this time the subjects stood to either gain up to $100 or lose up to $100 for each round they played.

What they found was that people who were very loss-averse (very afraid of forfeiting their money) did better when they were threatened with losing greater amounts. They choked, however, when offered a $100 award.

Meanwhile, those who weren't loss-averse (they didn't fear losing what they had) were mostly motivated by gaining more money. When threatened with losing $100, they fumbled.

In other words, human performance responds best to what matters most.

When the researchers looked through an MRI machine at the subjects' ventral striata—the brain's reward center—they found that activity in the region increased with the magnitude of the stakes. The more there was on the line, the more their brains lit up at the prospect. Again, for loss-averse people, losing money mattered more than winning it did, and vice-versa.

To Chib, this suggests that the ventral striatum mediates "how you process incentives and how they result in performance." The region tells the body what rewards (or punishments) await you, and, depending on your temperament, sends the information to the motor areas of the brain. As in, "Hey, you'd better not clip that hurdle; you won't get the gold medal." Perhaps Lolo Jones was simply loss-averse.

What's interesting about this study is that it implies that choking, largely understood to be an subconscious process, happens in part through interaction with another subconscious process: the brain's careful tallying of boons and costs, and how you'll react to either.

Chib said that right now, the findings can't be generalized to anything beyond financial incentives. But if your boss knows you're loss-averse, he could structure your bonus scheme in order to squeeze the best performance out of you. "He can tell you that you’ll get $500, but if you make mistakes, we’ll dock you," he said. "That’s counter to the traditional way of doing things. But this way, it maximizes performance, and you’ll get the incentive either way ... we would hope."