Repeated light blows to the head can harm cognition, according to a study by neuroscientist Anne Sereno and her team at the University of Texas Health Science Center at Houston. They don’t know if the impact is permanent or if there might be cumulative effects over time, and they concede more research is needed. But the findings add to a growing body of knowledge about the long-term risks of head trauma in sports and evidence suggesting repeated sub-concussive blows may be detrimental over time.

Read the article in Wired.