Even in absence of overt tasks, the human cortex manifests rich patterns of spontaneous "resting state" BOLD-fMRI fluctuations. However, the link of these spontaneous fluctuations to behavior is presently unclear. Attempts to directly investigate this link invariably lead to disruptions of the resting state. Here we took advantage of the well-established association between pupil diameter and attentional gain to address this issue by examining the correlation between the resting state BOLD and pupil fluctuations. Our results uncover a spontaneously emerging spatiotemporal pupil-BOLD correlation whereby a slow buildup of activity in default mode areas preceded both pupil dilation and wide-spread BOLD suppression in sensorimotor cortex. Control experiments excluded a role for luminance fluctuations or fixation. Comparing the pupil-correlated patterns to activation maps during visual imagery revealed a substantial overlap. Our results indicate a link between behavior, as indexed by pupil diameter, and resting state BOLD fluctuations. These pupil dilations, assumed to be related to attentional gain, were associated with spontaneously emerging antagonism between fundamental cortical networks.
Bibliographical noteFunding Information:
The authors wish to thank Michal Harel for the help in brain reconstructions, and Nahum Stern, Fanny Atar and Dr. Edna Haran-Furman for their technical MRI facility assistance. We also thank Amos Ariely, Dov Sagi, Alumit Ishai, Oren Shriki and the Malach lab members in general for the constructive discussions; in particular, Tal Golan, Meiri Meshulam and Michal Ramot for reviewing the manuscript and providing many helpful comments. This work was funded by the EU FP7 VERE, EU-Flagship HBP, ICORE program ( ISF 51/11 ) and the Helen and Martin Kimmel award to R.M.
© 2014 Elsevier Inc.
- Default mode network
- Locus coeruleus
- Pupil dilation
- Resting-state spontaneous fluctuations
ASJC Scopus subject areas
- Cognitive Neuroscience