title: Coupling between pupil fluctuations and resting-state fMRI uncovers a slow build-up of antagonistic responses in the human cortex.
abstract: 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.
authors.affiliation: Department of Neurobiology, Weizmann Institute of Science, 76100 Rehovot, Israel.
authors.forename: Dov
authors.initials: D
authors.lastname: Yellin
authors.affiliation: Department of Neurobiology, Weizmann Institute of Science, 76100 Rehovot, Israel.
authors.forename: Aviva
authors.initials: A
authors.lastname: Berkovich-Ohana
authors.affiliation: Department of Neurobiology, Weizmann Institute of Science, 76100 Rehovot, Israel. Electronic address: rafi.malach@gmail.com.
authors.forename: Rafael
authors.initials: R
authors.lastname: Malach
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007092:Imagination / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011680:Pupil / Q000502:physiology*
keywords: Default mode network; Locus coeruleus; Pupil dilation; Resting-state spontaneous fluctuations