President Barack Obama is drawing attention to youth sports concussions with a White House summit with representatives of professional sports leagues, coaches, parents, young athletes, researchers and others.
The Institute of Medicine and the National Research Council say not enough is known about how concussions may affect still-developing brains.
Obama on Thursday will also highlight millions of dollars in pledges and other support from the NFL, the National Institutes of Health and others to conduct research that could begin to provide answers.
The White House says Obama is concerned about the safety of his own daughters, who are active in sports. He once said he'd "have to think long and hard" before allowing a son to play football because of the risk of head injury.