Relatively few studies have examined the association between measures of functional connectivity and cognitive ability. Their findings generally suggest that functional connectivity of various brain regions have a significant relationship with certain cognitive abilities.55–56 In this study, the degree of functional connectedness between hippocampi is negatively associated with performance on an auditory verbal memory task, such that patients with less bilateral connectivity recalled more words after a delay than patients with greater interhemispheric connectivity. Given the role of the hippocampus in learning and memory, we hypothesized that interhemispheric hippocampal connectivity is associated with performance in this cognitive domain. Interestingly, the observed negative association between hippocampal connectivity and memory suggests cognitive functioning is not completely dependent on the integrity of structural connections. Additionally, these results hint at neural plasticity, as the data suggests hippocampal signal is rerouted to reach its homologous contralateral region through more indirect posterior connections (i.e., posterior commissure/thalamic nuclei) after TAI, and the degree of inefficiency (i.e., diffuse connectivity) seen in the pattern of hippocampal connectivity among patients may be evidence of this plasticity. However, while this plasticity
