. >> huss kerrs who volunteer to be a part of ramp undergo an eet while doing a memory test.s one - i have to identify which letters in a sequence match one two shots earlier. >> when it matches use button number one, when it doesn't, press four. >> they are going fast. >> we think the cap is a critical way of assessing whether a concussion occurred. >> you are also using brain scans and other technologies. >> we can collect mri data, other data, mri gives us information about structure of the brain and we can look at way. >> the images are from a football player without a concussion, and show changes in brainwave activity as a player distinguishes between a match and non-match. look at the player who had a concussion. there's no change. >> they are virtually identifiable. >> why is that? >> the brain hasn't figured out that this number is identical to that. at a minimum it's delayed. these are people experiencing a head injury previously. they may have had this for a year. after a year... >> you have a lingering effect. >> the brain is not processing it when it should have.