Official websites use. Share sensitive information only on official, secure websites. We probed these relationships in the cingulum bundle, a major white matter pathway of the default mode network. Participants performed cognitive tests measuring processing speed, memory and executive functions, and motor tests measuring motor speed and grip force. Our data revealed that only SC but not resting state FC was significantly associated with age. Further, the cingulum's SC and FC showed no relation.
Hum Brain Mapp —, Keywords: cingulum, cognitive aging, functional connectivity, multimodal imaging, tractography. It is well established that healthy aging is associated with changes in behavior, neuroanatomical, and functional brain metrics [Bennett and Madden, ; Ferreira and Busatto, ; Fjell and Walhovd, ].
One underlying mechanism for behavioral deterioration as well as for loss of functional connectivity FC could be described by the disconnection hypothesis [O'Sullivan et al. The hypothesis is based on Geschwind's proposal of disconnection syndromes [Geschwind, ], which suggests the importance of white matter WM networks for higher order function. Within this framework the decline in cognitive abilities could be related to deterioration of WM tract integrity because of its impact on communication between brain regions.
Indeed, there is evidence for microstructural deterioration of WM tracts in old age that seems to be more pronounced in frontal than in posterior brain regions [Bennett and Madden, ]. Several networks, each consisting of multiple brain regions, have been identified reliably [Fox and Raichle, ].
However, a recent longitudinal study investigating participants with a mean age of Nonetheless, studies investigating the association between SC and FC are still scant in the field of healthy aging. So far, one study found that integrity of the WM tract connecting the posterior cingulate cortex PCC and hippocampus was associated with FC strength between the two regions [Teipel et al. Unfortunately, the association between the underlying WM integrity and cognitive performance was not analyzed.
