The headband that measures boredom

Researchers at Tufts University near Boston have developed a brain sensor that can tell when you're bored, stressed or mentally overloaded. So how does it work?

Fitted as a headband, the device uses light to measure the wearer's level of mental exertion - when the brain is working harder, blood flow increases and the area absorbs more light.

This could allow a computer to automatically make changes to a person's workload based on their mental exertion.

For example, if an air traffic controller wearing the device is overworked or tired, the computer would know this and could send the next plane to another person.

The BBC's Rajini Vaidyanathan went to the lab to see how it works - and what it could mean for the future.

Filmed by Ian Cartwright; edited by Ashley Semler; graphic by David Botti

Living Online is a series of video features published every Tuesday on the BBC News website which look at how technology converges with culture and all aspects of our daily lives.