Spontaneous BOLD event triggered averages for estimating functional connectivity at resting state

ENZO TAGLIAZUCCHI; PABLO BALENZUELA; DANIEL FRAIMAN; PEDRO MONTOYA; DANTE CHIALVO

NEUROSCIENCE LETTERS

ELSEVIER IRELAND LTD

Año: 2011 vol. 488 p. 158 - 163

0304-3940

Recent neuroimaging studies have demonstrated that the spontaneous brain activity reflects, to a large extent, the same activation patterns measured in response to cognitive and behavioral tasks. This cor- respondence between activation and rest has been explored with a large repertoire of computational methods, ranging from analysis of pairwiseinteractions between areas of the brain to the global brain networks yielded by independent component analysis. In this paper we describe an alternative method based on the averaging of the BOLD signal at a region of interest (target) triggered by spontaneous incre- ments in activity at another brain area (seed). The resting BOLD event triggered averages (“rBeta”) can be used to estimate functional connectivity at resting state. Using two simple examples, here we illus- trate how the analysis of the average response triggered by spontaneous increases/decreases in the BOLD signal is sufficient to capture the aforementioned correspondence in a variety of circumstances.The com- putation of the nonlinear response during rest here described allows for a direct comparison with results obtained during task performance, providing an alternative measure of functional interaction between brain areas.