n the old newsreel, the year is 1949. The Cleveland Browns are playing the newly minted San Francisco 49ers. The players wear leather helmets and no face masks. A 49er running back, John "Strike" Strzykalski, takes the ball off tackle and darts through the line. Several Browns converge to knock him down, but Strike struggles up from the turf, plunges another 10 or 12 yards, takes another hit, and staggers, fighting for inches until he goes down inside the 49er five yard line. It is one of those moments people celebrate in sports—a moment when a player sacrificed his body for the sake of the team.

No one can say for sure that football injuries have caused Strzykalski's cognitive problems. His symptoms may be a natural consequence of aging. But his wife, Betty, recalls that even when John was younger, he was forgetful.

"Many, many times, he would say, ‘If you'd gotten hit in the head as much as I did playing football, you'd forget things, too,'" she says. "When he played, they didn't have the equipment and the medical attention the players get today. He would get dizzy a lot and confused, but they never thought about taking him out of the game. The trainer would say, ‘Take an aspirin, you'll be okay.'"

evin Guskiewicz knows better. Guskiewicz, director of Carolina's Sports Medicine Research Laboratory, is also research director of the new Center for the Study of Retired Athletes. He studies head injuries, investigating the possibility that repeated concussions are associated with the early onset of diseases such as Parkinson's and Alzheimer's, and other neurological disorders.

"If you take a blow to the head, you're going to have a group of axons, probably thousands of them, that are injured," he says. "For example, the front part of the brain is associated with learning and memory and higher-order thought processes, so a blow to the front of the head might lead to temporary memory loss or confusion. Usually, that disruption is very short. But if we send that person right back into the game, those axons may not have time to recover and heal before the next blow. We can't see this kind of injury the way we can see the black-and-blue swelling from an ankle sprain, for instance. We rely on very subjective information such as the athlete saying, ‘I just don't feel right. I feel dizzy. I have this ringing in the ears, I have blurred vision.' But these guys want to get back into the game. So, many times, the decision comes down to guesswork."

One goal of the new center, Guskiewicz says, is to eliminate the guesswork. He envisions research that would, over time, lead to better equipment, better rules, and better guidelines for return-to-play decisions. So today, he is speaking to a group of former pro players and their wives who have gathered at Carolina to try to make life better for the players who follow them. After they've heard from Guskiewicz and Carolina's new head football coach, John Bunting, the players will evaluate a survey that Guskiewicz plans to send to 3,600 retired professional players nationwide. The survey will gather information the center needs to identify the most pressing health problems of retired players and to help set priorities for research.