Researchers from Cornell University have created a tool to measure worker alertness levels, as evidenced by their pupil size, with the goal of understanding what causes such fluctuations and determining how to improve employee productivity.

"Since our alertness fluctuates, if we can find a pattern it will be very useful to manage and schedule our day," said Vincent W.S. Tseng, a doctoral student in information science and lead author of "AlertnessScanner: What Do Your Pupils Tell About Your Alertness."

Current methods for analyzing alertness levels tend to rely on outfitting people with cumbersome devices, so a team of researchers in Cornell’s People-Aware Computing Lab, led by Tanzeem Choudhury, associate professor of information science and senior author of the study, set out to develop an unobtrusive method for continuously measuring alertness.

"Since people use their phones very frequently during the day, we were thinking we could use phones as an instrument to understand and measure their alertness," Tseng said. "And since people's eyes are affected by their alertness, we were thinking that when people are looking at their phones, we could use a moment to measure their alertness at that point."

Pupils dilate when a person is alert, thanks to a mechanism triggered by the sympathetic nervous system which makes it easier to absorb information. Conversely, when a person is drowsy, the parasympathetic nervous system triggers a mechanism that contracts the pupils.

AlertnessScanner measured such dilations and contractions by capturing images of the pupil through a burst of photographs taken whenever users unlock their smartphones. The research team suggests that the AlertnessScanner could be used in the healthcare industry by medical professionals, as well as a variety of other workplace settings, according to Tseng.

"If you want to get something very important done, then probably you should execute this task while you're at the peak of your alertness; when you're in a valley of your alertness, you can do something like rote work," Tseng added. "You'll also know the best time to take a break in order to allow your alertness or energy to go back up again."

The research was presented at the 20th International Conference on Human-Computer Interaction with Mobile Devices and Services.