Monitoring of 11 football players at a high school in Indiana, who wore helmets equipped with sensors that recorded impart, has revealed the problem of head injuries is deeper than was thought. Brain scans and cognitive tests, in addition to the impact data, found that some players who hadn't been diagnosed with concussions nevertheless had developed changes in brain function, correlated with cognitive impairment. The findings point to the dangers of repeated impact, regardless of whether consciousness is lost.
The research is ongoing, and aims to determine how many blows it takes to cause impairment, and whether players accumulate damage over several sessions, or recover. The work to date suggests that those who developed impairment in the absence of concussion received a large number of blows primarily to the top and front of the head. This is just above the dorsolateral prefrontal cortex, which showed changes in activation. Visual working memory was the function principally affected.
Researchers are also working to create a helmet that reduces the cumulative effect of impacts.