We don’t think much about blinking. For the most part, it’s an involuntary process that keeps our eyes hydrated. But when we blink, we lose information, even if it’s just for a fraction of a second. In fact, during a typical day, blinking means you spend about 44 minutes with your eyes closed.

This is why, when we’re watching something that interests us, we tend to blink less often. Again, it’s not something we think about, just an involuntary response to not wanting to miss out on whatever has captured our attention.

A recent study of the blink patterns of two-year-olds –some of whom were typically developing children and some of whom had an autism spectrum disorder—revealed fascinating insights on what is actually happening in their brains.  Noticing that children blink less often while watching videos, researchers wondered if toddlers with autism, who have impairments in social communications, would show the same blink patterns as typically developing kids.

They showed 93 toddlers a video featuring two children in a wagon who get into an argument over whether the wagon door should be open or shut.

What they discovered was that typically developing toddlers blink less—indicating increased interest—during the emotional exchange between the two children in the video.

Toddlers with autism, however, blinked less—indicating increased interest—during the parts of the video that showed physical objects in motion, such as the wagon door being slammed.

Geraldine Dawson, chief science officer for Autism Speaks, says that if a child is not visually engaged with the social world, it can “impact the development of neural systems that underlie social behavior which rely on social stimulation for development.”

One of the benefits of the study is that it provides a way to measure a child’s interest and engagement with various stimuli, and can even be used to gauge the effectiveness of various therapies.