Why Do We Choke Under Pressure? A Monkey Study Explains

A recent study sheds light on why both humans and monkeys struggle to perform under pressure when high rewards are at stake. Researchers found that stress interferes with brain signals essential for executing movements, leading to subpar performance. The study involved three monkeys performing tasks to earn water as a reward. When the reward was moderate, the monkeys excelled. However, when faced with a potentially large jackpot, their performance dropped significantly. This finding is consistent with experiences seen in high-stakes settings such as competitive sports or the performing arts.

Understanding Motor Preparation

The research, which was published in the magazine Neuron tested the monkeys’ speed and accuracy as they reached for a target on a screen. The monkeys had to wait for a signal telling them when to reach, with different signal colors corresponding to different reward sizes. Before the official tests, the scientists confirmed that the monkeys could identify larger rewards with near-perfect accuracy.

During the experiments, researchers monitored hundreds of neurons in the monkeys’ brains using implanted electrodes, focusing on areas involved in “motor preparation.” Strikingly, the monkeys performed worst when the reward was too small or too large. Adam Smoulder, a doctoral student at Carnegie Mellon University and lead author of the study, noted that the monkeys seemed overly cautious when a large reward was involved, which hampered their speed.

Implications for human behavior

The study suggests that the size of a reward affects whether the brain reaches an “optimal zone” for motor preparation, where performance is maximized. When rewards exceed this optimal point, performance deteriorates. Co-senior author Steven Chase, a professor of biomedical engineering at Carnegie Mellon, emphasized the importance of these findings for understanding human behavior, particularly in contexts such as addiction and obsessive-compulsive disorder.

The researchers want to identify ways to facilitate these optimal neural patterns to improve performance under pressure. Christopher Mesagno, a senior lecturer at Victoria University, marked that while this study provides insight into neural pathways, future research could further investigate the effects of social anxiety in humans.