Differential lateralization of hippocampal connectivity reflects features of recent context and ongoing demands: An examination of immediate post-task activity.
Neuroimaging studies have shown that task demands affect connectivity patterns in the
human brain not only during task performance but also during subsequent rest periods. Our
goal was to determine whether ongoing connectivity patterns during rest contain
information about both the current rest state, as well as the recently terminated task.
Our experimental design consisted of two types of active tasks that were followed by two
types of low-demand rest states. Using this design, we examined whether hippocampal
functional connectivity during wakeful rest reflects both features of a recently
terminated task and those of the current resting-state condition. We identified four
types of networks: (i) one whose connectivity with the hippocampus was determined only by
features of a recently-terminated task (ii) one whose connectivity was determined only by
features of the current resting-state, (iii) one whose connectivity reflected aspects of
both the recently-terminated task and ongoing resting-state features, and (iv) one whose
connectivity with the hippocampus was strong, but not affected by any external factor.
The left and right hippocampi played distinct roles in these networks. These findings
suggest that ongoing hippocampal connectivity networks mediate information integration
across multiple temporal scales, with hippocampal laterality moderating these connectivity