One of the world’s largest studies to explore the impact of concussions was recently awarded $22 million in new funding.

The Concussion Assessment, Research and Education Consortium, or CARE was created in 2014 and is led by the Indiana University School of Medicine.

The first phase of the trial has collected data on nearly 40,000 student athletes and cadets. This second phase of the large-scale, multi-site concussion trial will allow researchers to follow participants and study the impact of repetitive head injury.

IU School of Medicine, Department of Psychiatry Chairman Dr. Tom McAllister says some of those participants will react differently than others.

“So it raises the question of whether there are individual thresholds for developing concussion,” says McAllister.

The CARE trial has also generated information about sleep and concussion recovery, and the influence of a player’s age.

McAllister says already the study has shown that concussion recovery time varies.

“What we don’t know is whether people are being more cautious, or if people are paying more attention to it and therefore athletes have a better sense of their symptoms and are reporting it more accurately,” says McAllister.

The study could also help identify biomarkers and genetic factors to identify who may be more at risk.

The funding comes from the U.S. Department of Defense and the NCAA.