Stress test: This graph shows my stress levels throughout the course of a typical day. The three colored lines at the bottom are accelerometer readings; above that is a temperature reading. In the middle of the graph is the skin conductance, indicating stress levels. Sharp drop-offs (at 1:20 and 3:16) indicate that the sensor reset itself. Spikes of stress occurred in the morning, when I was multitasking and replying to e-mails.

Now that I know multitasking can be more stressful to me than a meeting, what can I do with the information? Picard is working on ways for the Q Sensor to give immediate feedback by, for example, transmitting data to a smart-phone app. The device could then issue an alert to serve as a reminder to relax.

Picard says the sensor could also help in more dire situations—for example, helping to prevent drug relapses (researchers have shown that drug cravings trigger peak levels of physiological stress). Picard is in the process of setting up a study with post-traumatic stress patients being treated for addiction at a Veterans Affairs rehabilitation center. For the study, phones supplemented with psychological surveys and positive messages will read and respond to a person’s Q Sensor.

Kevin Laugero, a professor in the department of nutrition at the University of California, Davis, studies the neurophysiology of eating and the ways in which stress can affect decision-making related to food intake. He is using the Q Sensor in combination with other tools to look into whether preschool children are more likely to eat a snack when their stress levels are high. In the past, Laugero and his team had to measure stress by taking samples of saliva and checking the levels of the stress hormone cortisol, a process that yielded intermittent rather than continuous data.

The Q Sensor has business applications as well. “It is becoming an active part of our diagnostic set,” says John Ross, CEO of Shopper Sciences, a marketing and advertising firm that helps companies understand consumer behavior. When a fast-food company wanted to know why customers were not returning to its restaurants despite reporting overall satisfaction with the food and atmosphere, Ross used the Q Sensor to solve the mystery. It turns out it was the process of selecting the food from the menu that was frustrating customers, says Ross. 

Ross is planning to build an extensive Q Sensor database to learn about patterns in larger groups and predict consumer reactions to different situations. “Our goal is to have the largest database of shopper physiological response of any company in North America by the end of the year,” says Ross. 

Picard hopes the device could eventually have broad appeal. A lot of people simply don’t know or believe they’re stressed. “This is technology that can transform people’s ability to understand themselves and participate in the process of health and medicine,” she says.