Resting-State Functional Connectivity in Collision and Contact Female Athletes Over the Course of a Season

Objective: University contact and collision sport athletes are exposed to numerous impacts to the body and head, however, the short-term effects of such cumulative hits on neurological functioning remain elusive. This study examined resting-state functional connectivity (rsFC) of brain networks in a sample of female varsity athletes over the course of a season.

Design: 19 female university athletes involved in contact (N = 7) and collision (N = 12) sports underwent functional MRI scans at both pre- and post-season. A group-level independent component analysis (ICA) was used to investigate differences in rsFC over the course of a season and differences between contact and collision sport athletes. Follow-up analyses examined the main effects of contact group and time.

Results: Decreased rsFC was observed over the course of the season between the default mode network (DMN) and regions in the frontal, parietal, and occipital lobe (pFDR < 0.05). Follow-up analyses indicated that these differences were driven by pre-season vs. post-season differences in the contact group. There was also a main effect of group, showing increased rsFC between the dorsal attention network (DAN) and the right superior frontal gyrus and decreased rsFC with the right supramarginal gyrus (pFDR < 0.05) that was driven by differences between contact and collision groups at pre-season.

Conclusions: Differences identified over the course of a season of play indicate largely decreased rsFC within the DMN, which may have been driven by rsFC changes in contact athletes, consistent with prior literature. Additionally, we observed that level of contact was associated with differences in rsFC of the DAN in female varsity athletes. The association between exposure to repetitive head impacts (RHIs) and observed changes in network rsFC supplements the growing literature suggesting that even non-concussed athletes may be at risk for changes in brain functioning. However, the complexity of examining the direct effects of RHIs highlights the need to consider multiple factors including mental health and sport specific training and expertise, which may potentially be associated with neural changes.