The brain activity patterns and performance on a cognitive task of retired National Football League (NFL) players and a group of healthy volunteers are compared in Scientific Reports this week. The research supports the hypothesis that NFL alumni may be more likely to develop executive dysfunction (disruption to a range of cognitive processes involved in organization and regulation).
Recent research has highlighted the prevalence of mild traumatic brain injuries (mTBIs) and the potential for long-term neurological damage in players of contact sports, including professional American football. However, the reliable detection and monitoring of the long-term consequences of repetitive mTBI in living subjects has remained challenging.
Adam Hampshire and colleagues studied a group of 13 retired National Football League players and 60 healthy volunteers, who completed an executive function task that involved rearranging coloured balls in a series of tubes in as few steps as possible. The authors analysed participants’ performances on the task and evaluated their brain activity patterns using functional magnetic resonance imaging (fMRI). The NFL alumni showed only modest performance deficits compared to the control group. However, the results of the fMRI for the NFL group also showed pronounced hyperactivation and hypoconnectivity in the frontal lobe, and this abnormal function correlated with the number of times the retired player reported having been removed from play after head injury. The results suggest that former NFL players may be more likely to experience certain executive dysfunctions, and highlight how fMRI can help to reveal potential underlying neural abnormalities.
The authors caution that large-scale and longitudinal neuroimaging studies are needed in order to further examine the potential long-term neurological consequences of mTBIs. NFL alumni are a particularly select - and thus hard to recruit - population, as reflected in the study’s sample size. Additionally, there were some differences between the NFL group and the control group, including physical size, although weight, head size and brain size were not related to the number of times that players had been removed from play after head injury and brain size did not differ across groups.