Abstract
OBJECTIVE: A mild traumatic brain injury (mTBI), or concussion, has known neuropsychological sequelae, and neuroimaging shows disturbed brain connectivity during the resting state. We hypothesized that task-based functional connectivity measures, using magnetoencephalography (MEG), would better link the neurobiological underpinnings of cognitive deficits to specific brain damage. METHODS: We used a mental flexibility task in the MEG and compared brain connectivity between adults with and without mTBI. RESULTS: Affected individuals showed significant reductions in connectivity. When challenged with a more difficult task, these individuals were not able to "boost" their connectivity, and as such, showed deterioration in performance. INTERPRETATION: We discuss these findings in the context of limitations in cognitive reserve as a consequence of a mTBI.