It was once thought that taking big hits over a period of time is what causes lifelong damage to the brain. Now researchers have found that even after one season of college football, “normal” contact results in harmful effects. 36 players were outfitted with sensors to detect helmet contact. Over the season, these players recorded over 19,000 “normal” hits. Brain scans showed that the white matter in the brain was affected by these impacts—a measure of how well the nerves transmit signals.