If you’ve ever been in mid-conversation at lunch only to lose your train of thought when your cell phone buzzed, a new study published in Nature Communications offers an explanation of what’s happening in your brain to cause this.

Neuroscientist Adam Aron from the University of California San Diego and postdoctoral scholar Jan Wessel found that the subthalamic nucleus (STN)–the brain system that is involved in interrupting or stopping movement in our bodies–also interrupts cognition. In previous research, Aron identified that the STN is engaged when you make an abrupt stop in action due to an unexpected event.

“A broad stop is the sort of whole-body jolt we experience when, for example, we’re just about to exit an elevator and suddenly see that there’s another person standing right there on the other side of the doors,” he writes in the study.

This new research finds that an unexpected event also appears to clear out what you were thinking. This function of the brain served an important role when humans could be confronted with danger and needed a fight or flight response, but today it has negative consequences.

“Clearly this happens all day long to us,” says Aron. “We’re concentrating at the office, and things go ‘cheep.’ We get distracted, but that’s everyday life. Unfortunately, there’s a big cost to that when it comes to focus, and it’s increasing in this world.”

While the reaction is physiological, you can work to strengthen your focus so that the smaller distractions don’t cause full stops in your thinking. Here are six things that will help you pay attention:

Just like exercising trains your muscles, meditation trains of your attention, allowing you to stay at attention for longer periods of time. When distractions come, your brain is strong enough to let them go by without engaging them.