This study has the following limitations. First, most of the participants were females in early adulthood, which limits the generalizability of the results to all adults. Second, as our results were not significantly derived under the multiple comparison correction, the present results should be interpreted carefully. Third, as EEG was performed only in a resting state but not during a visual memory task, direct comparisons of EEG activity in the resting state and during memory task performance were not possible. Therefore, further research in which EEG activity recorded during the memory task and resting-state is compared would allow for a clearer understanding of the default mode network and the neural mechanisms of visual memory. Fourth, this study used only spectrum and FC analyses. The application of network analysis would provide additional information about the connectivity efficiency, as well as the number of connections that show differences between groups.
