About TEDMED Now
Performance is often treated as a fixed measure of ability. But under pressure, something more complex is happening.
In this episode of TEDMED Now, Kelly Thomas revisits Sian Leah Beilock’s research to examine why performance can break down precisely when it matters most. The focus is not on failure, but on mechanism: how stress alters attention, disrupts working memory, and shifts the way the brain executes well-learned skills.
What has become clearer over time is that “choking” is not a deficit of talent. It is a mismatch between practiced conditions and real-world stakes. When pressure introduces unfamiliar cognitive demands, even expertise can falter.
This episode explores how that understanding changes the path forward. If performance is context-dependent, then preparation must be as well. Practicing under conditions that simulate pressure can help stabilize performance when it counts.
Revisiting this idea reframes a common experience. The question is no longer why we fail under pressure, but how we design environments that allow us to perform as intended when it matters most.
About Kelly Thomas
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Kelly Thomas, PhD is Director of Scientific Content at TEDMED, where she curates and translates breakthrough ideas at the intersection of science, medicine, and human potential. Her work focuses on making complex research clear, accurate, and meaningful — connecting rigorous evidence to the realities of everyday life.
With a background spanning biomedical engineering, structural biology, oncology, and the biology of the stem-cell niche in acute myeloid leukemia, Kelly has written across formats ranging from peer-reviewed research and grant proposals to health and wellness journalism. Throughout her career, she has been driven by a central question: how do we translate the best of science into longer, healthier, more meaningful lives?
At TEDMED, she leads the development of conversations and experiences designed to surface nuance, challenge assumptions, and make emerging science accessible without oversimplifying it. As one of the hosts of TEDMED Conversations, she explores topics including resilience, mental health, technology’s impact on youth, and the future of care.
A lifelong athlete and high-performance competitor, Kelly brings a particular interest in the neuroscience of resilience and behavior change — and how science can inform the way we live, train, recover, and grow.
About Sian Leah Beilock
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About Sian
Sian Leah Beilock is the president of Dartmouth College and a renowned cognitive scientist. Her research explores the science behind why people “choke” under pressure and how we can perform our best in stressful situations, whether it’s a big test, a public speech, or a championship game. By using a variety of research methods, from test performance to brain scans, she studies how our thoughts and reasoning skills change when we are under stress. Her work has been recognized with the Troland Award from the National Academy of Sciences and has been featured in major media outlets like The New York Times and NPR. Sian is the author of two acclaimed books: Choke and How the Body Knows Its Mind. She previously served as the president of Barnard College and was a leader at the University of Chicago. Today, she applies her knowledge of the human mind to guide one of the nation’s top universities.
