Anna Leigh Rack-Gomer1,2, Joy Liau3,
Thomas T. Liu1,2
1Bioengineering, UC San Diego, La
Jolla, CA, United States; 2Center for Functional MRI, UC San
Diego, La Jolla, CA, United States; 3School of Medicine , UC San
Diego, La Jolla, CA, United States
Interpretation
of inter-subject differences in resting-state functional connectivity is
complicated by the BOLD signals dependence on vascular factors. We found
functional connectivity strength to be correlated with resting-state
fluctuation amplitude (RSFA) across healthy subjects, where RSFA has
previously been shown to correspond to vascular reactivity within subjects.
However, we did not find RSFA to be related to either the task-related
cerebral blood flow (CBF) response or baseline CBF, suggesting that RSFA does
not indicate vascular differences across subjects. Instead, RSFA may reflect true differences
in spontaneous neural activity, which contribute to the normal variability
found in resting-state functional connectivity.