How your pupils react to light exercise can reveal whether you’re getting one of the main benefits of movement – the cognitive boost associated with improved mood and improved executive function.
Researchers in Japan monitored pupil size in 24 participants during 10 minutes of light exercise, and then used neuroimaging to see how the participants’ brains responded to the cognitive task.
It was only a small test, but the results showed that the more pupils dilated during light exercise—in other words, the bigger they got—the better the cognitive boost they received.
“This finding supports our hypothesis that mechanisms related to pupillary…is a potential mechanism by which light exercise increases activation of the prefrontal cortex and executive function.” Explain The team of neuroscientists and exercise scientists at the University of Tsukuba in their article.
Although it seems like a strange connection, it is now firm Those exercises, even low-intensity exercises such as yoga that it He walksit can improve our mood and help us focus better to complete a task – benefits that involve frontal cortex from the brain.
But the exact neural activity driving this increase in executive function from exercise is still not well understood.
One way to understand what is happening inside our brain is through our eyes. previous searches showed that Our students It may reflect deeper neural activity.
To investigate further, the researchers recruited healthy young adults and asked half of them to participate in 10 minutes of very light exercise and the other half to act as a control group and simply rest on an exercise machine.
Before, during and after the training period, pupil size was monitored non-invasively and participants were also asked about their mood.
A graphic summary summarizing the team’s results. (Quizo et al., NeuroImage, 2022)
Both groups underwent an executive function test before and after the training. This was called Color Stroop task It asked if a word (red or green, for example) matched the color in which it was displayed.
While performing this test, the team studied the participants’ prefrontal brain activity using functional infrared spectroscopy.
The results showed that light exercise made the participants perform better on the cognitive task compared to the control group, and this was associated with an increase in activity in Left dorsolateral prefrontal cortex of the brain, a region associated with executive function.
Interestingly, they also showed that the pupils of the exercise group dilate as they worked, while the pupil size of the control group did not change.
The more dilated a participant’s pupils were during training, the better the increase in cognitive function when they were given the test at the end.
“These findings strongly suggest that the improvement in prefrontal executive function resulting from light exercise can be attributed to neural activity associated with the pupil,” Explains a press release.
“Looking to the future, pupil diameter has promising potential as a new biomarker that can be used to predict the effects of exercise on the brain.”
This is the first study to suggest that the part of the central nervous system that underlies pupil dilation is linked to the cognitive boost that comes from exercise.
Of course, it’s just a small preliminary study. You The researchers explain The findings are limited by considering only healthy young men and an unequal group of men and women.
Follow-up studies are needed to confirm that this effect is real. Then we can start to see what that means and how we can benefit from it.
But it’s a fascinating new look at the relationship between our brains and our eyes — as well as how exercise can change our brain function.
Research published in NeuroImage.
By Fiona McDonald
Posted in ScienceAlert
Emily Brontë is a journalist and feature writer specialising in culture, entertainment, literature, and current affairs. She is dedicated to producing clear, accurate reporting that helps readers stay informed about developments in the UK and around the world.
