In low-light situations, a person’s pupils naturally widen to let in more light. But a new study shows that pupils also dilate when a person is focused on tasks. The researchers found that the more a person’s pupils dilated during a task, the better they performed on tests measuring their working memory. Working memory is a cognitive skill that helps people process information without losing track of what they’re doing.The brain uses working memory to carry out immediate tasks, such as loading the dishwasher, and to decide what information to store for future use, like whether more dishwasher soap will be needed. Researchers at the University of Texas at Arlington are studying the variation in working memory among individuals and conducted an experiment to determine if studying a person’s pupils could be an indicator of their working memory. Typically, a person’s pupils dilate in low-light environments.The researchers found that people’s pupils dilate not only in response to light, but also when they are focusing on tasks. Their study, published in the peer-reviewed journal Attention, Perception & Psychophysics, revealed that greater pupil dilation during task performance was associated with better performance on tests of working memory. According to Robison, the lead researcher, those who performed poorly on the tasks had less pupil dilation, while the top performers had larger pupil dilations and were more selective in the information they processed.The researchers recruited 179 undergraduate students at UT Arlington to participate in a study. The students completed working memory tasks where they had to remember information for a short amount of time. During the tasks, their pupils were continuously measured using an eye-tracker, similar to what optometrists use during eye exams.
The researchers found that participants who paid more intense and consistent attention, as indicated by their dilated pupils, performed better on the memory tasks. The high performers also showed more pupil sensitivity.
