How often a preschooler blinks naturally may offer a small clue about developing cognitive skills, according to a study published in Communications Psychology. Researchers found that children with higher blink rates tended to perform better when switching rules in a card-sorting game and showed greater activity in a region of the prefrontal cortex involved in the task.
The study included 113 children aged 35 to 80 months, recruited from two preschools in Osaka and Kyoto. The children sorted picture cards first by color, then by shape, and later under changing rules. Researchers recorded their natural blinks on video and used functional near-infrared spectroscopy to monitor activity in regions of the prefrontal cortex.
Blink rate was positively associated with switching accuracy. The relationship remained after the researchers accounted for age, suggesting it was not explained solely by older children tending both to blink more and perform better. However, the age-adjusted association was modest.
The team also found that activity in the right dorsolateral prefrontal cortex was associated with both blink rate and task performance. The pattern fits with the idea that brain activity becomes more specialized as children develop, with older participants showing stronger engagement in this upper-right prefrontal region. The researchers stress that the data capture a single point in time and cannot establish cause and effect.
Spontaneous blinking is easy to record, potentially even with an ordinary video camera, so it could be useful in future research on early development. But the authors say it is not a reliable way to evaluate or diagnose individual children. Blink rate is affected by factors beyond brain development, and the study measured executive function using only one visual sorting task. The researchers say further studies following children over time and using other tasks are needed.
Sources: PsyPost.