You've just been injured, and you're on the way home from an hour of physical therapy. The last thing you want to do on your own is confusing exercises that take too long to show results. TED Fellow Cosmin Mihaiu demos a fun, cheap solution that turns boring physical therapy exercises into a video game with crystal-clear instructions.

You've just been injured, and you're on the way home from an hour of physical therapy. The last thing you want to do on your own is confusing exercises that take too long to show results. TED Fellow Cosmin Mihaiu demos a fun, cheap solution that turns boring physical therapy exercises into a video game with crystal-clear instructions.

Liver cancer is one of the most difficult cancers to detect, but synthetic biologist Tal Danino had a left-field thought: What if we could create a probiotic, edible bacteria that was "programmed" to find liver tumors? His insight exploits something we're just beginning to understand about bacteria: their power of quorum sensing, or doing something together once they reach critical mass. Danino, a TED Fellow, explains how quorum sensing works -- and how clever bacteria working together could someday change cancer treatment.

Did you know that you're 30 times more likely to laugh if you're with somebody else than if you're alone? Cognitive neuroscientist Sophie Scott shares this and other surprising facts about laughter in this fast-paced, action-packed and, yes, hilarious dash through the science of cracking up.

In 2014, the world avoided a global outbreak of Ebola, thanks to thousands of selfless health workers -- plus, frankly, some very good luck. In hindsight, we know what we should have done better. So, now's the time, Bill Gates suggests, to put all our good ideas into practice, from scenario planning to vaccine research to health worker training. As he says, "There's no need to panic ... but we need to get going."

Childhood trauma isn’t something you just get over as you grow up. Pediatrician Nadine Burke Harris explains that the repeated stress of abuse, neglect and parents struggling with mental health or substance abuse issues has real, tangible effects on the development of the brain. This unfolds across a lifetime, to the point where those who’ve experienced high levels of trauma are at triple the risk for heart disease and lung cancer. An impassioned plea for pediatric medicine to confront the prevention and treatment of trauma, head-on.

We'll go to the doctor when we feel flu-ish or a nagging pain. So why don't we see a health professional when we feel emotional pain: guilt, loss, loneliness? Too many of us deal with common psychological-health issues on our own, says Guy Winch. But we don't have to. He makes a compelling case to practice emotional hygiene — taking care of our emotions, our minds, with the same diligence we take care of our bodies.

60% of people with dementia wander off, an issue that can prove hugely stressful for both patients and caregivers. In this charming talk, hear how teen inventor Kenneth Shinozuka came up with a novel solution to help his night-wandering grandfather and the aunt who looks after him ... and how he hopes to help others with Alzheimer's.

"Ebola threatens everything that makes us human," says Bruce Aylward of the World Health Organization. And when the Ebola epidemic exploded in 2014, it caused a worldwide panic. But humanity can beat Ebola -- and Aylward shows four strategies that show how we are succeeding. The fight against Ebola is not yet won, he says, but it can be.

Why do some people struggle more than others to keep off the pounds? Social psychologist Emily Balcetis shows research that addresses one of the many factors: our vision. In an informative talk, she shows how when it comes to fitness, some people quite literally see the world differently -- and offers a surprisingly simple solution to overcome these differences.