Pupils enlarge when people focus on tasks



Our pupils typically enlarge in the dark to allow more light to enter our eyes. However, new research revealed some intriguing findings. They found that when we are intensely concentrated on anything, such as a task, our pupils also enlarge. Furthermore, we do better on working memory tasks when our pupils dilate more during this concentration.

The ability to process information without losing track of what we’re doing is known as working memory. It functions similarly to short-term memory, enabling us to do jobs quickly, like loading the dishwasher. However, it also assists us in making future decisions in the long term, such as whether to purchase additional dishwasher soap.

The University of Texas at Arlington’s scientists sought to discover why some people had superior working memory. So, they experimented. Researchers looked at their pupils to find out more about people’s working memory.

Matthew Robison, an assistant professor of psychology, said, “What we found was that the lowest performers on the tasks showed less pupil dilation. For the highest-performing participants, their pupil dilations were larger overall, and the individuals were more discerning about the information they were asked to recall.”

Robison and Garner recruited 179 UT Arlington college students to participate in their study. These pupils completed various memory exercises requiring them to retain information briefly. Like what eye physicians use, the researchers used an advanced gadget called an eye-tracker to monitor pupils’ movements while completing these tasks.

Robison said“We found that people who more intensely and consistently paid attention, as measured by their pupils being dilated more, performed better on the memory tasks. Importantly, we found that high performers also showed more pupil sensitivity than low-performing participants. This is exciting research because it adds another valuable piece of the puzzle to our understanding of why working memory varies between individuals.”

Journal Reference:

  1. Robison, M.K., Garner, L.D. Pupillary correlates of individual differences in n-back task performance. Atten Percept Psychophys (2024). DOI: 10.3758/s13414-024-02853-2


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