WASHINGTON (AP) — NFL doctors, trainers and players spent much of Wednesday discussing football and brain injuries. Their conclusion: They've still got a lot to learn.

"The fairly unanimous feeling today was that we needed new studies," said Dr. Constantine Lyketsos of Johns Hopkins University.

Concussions in the NFL have become a major topic of concern during the past year. The league has implemented new return-to-play guidelines for players who suffer concussions in practice or a game, and each team must consult with an independent neurologist whenever there is a head injury.

While the NFL may have appeared less pro-active regarding concussions in the past — and at odds with independent research or the players' union — the league's representatives say that tone has changed.

"I think your key is 'in the past,'" said Dr. Richard Ellenbogen, a co-chairman of the NFL's revamped head, neck and spine medical committee. "I think going forward, we are walking lock step. We have a very audacious goal in front of us."

That goal, according to Ellenbogen, is to change the culture among NFL players, who have a tendency to downplay head injuries. Players want to stay on the field, keep their jobs and sign more lucrative contracts.

Trying to reverse that thought process won't be easy.

Some of the culture-changing ideas suggested by doctors could be a challenge to implement on a practical basis to a group of sweaty players on a Sunday afternoon.

Ellenbogen and co-chairman Hunt Batjer broached the idea of giving players some sort of financial incentive for reporting concussions. They also suggested finding a way to ensure players wouldn't lose their place in the lineup or the roster if they miss time with a concussion.

They also discussed the possibility of putting a transmitter in the helmet of every player — to record every major and minor blow and gauge the cumulative effect. Lyketsos cited experiments with University of North Carolina players that found players averaged 950 hits to the head per season.

More practical ideas continue to be discussed and debated: cutting back on offseason practice time, reducing hitting during in-season practices, making helmets safer, educating players to stop tacking headfirst.

But Lyketsos said there are still gaps in what doctors know about football's long-term effects on the brain. He said there needs to be more than the "smattering of studies" that have been done so far.

"So it now becomes a matter of getting the powers-that-be together to design the studies, getting the players to participate," Lyketsos said, "and to find the funding."