Attention is commonly thought to be manifest through local variations in neural gain. However, what would be the effects of brain-wide changes in gain? We hypothesized that global fluctuations in gain modulate the breadth of attention and the degree to which processing is focused on aspects of the environment to which one is predisposed to attend. We found that measures of pupil diameter, which are thought to track levels of locus coeruleus norepinephrine activity and neural gain, were correlated with the degree to which learning was focused on stimulus dimensions that individual human participants were more predisposed to process. In support of our interpretation of this effect in terms of global changes in gain, we found that the measured pupillary and behavioral variables were strongly correlated with global changes in the strength and clustering of functional connectivity, as brain-wide fluctuations of gain would predict.
Bibliographical noteFunding Information:
We thank N. Turk-Browne and P. Dayan for helpful comments on earlier versions of the manuscript. This research was funded by US National Institutes of Health grants R03 DA029073 and R01 MH098861, a Howard Hughes Medical Institute International Student Research fellowship to E.E. and a Sloan Research Fellowship to Y.N. The authors also wish to thank the generous support of the Regina and John Scully Center for the Neuroscience of Mind and Behavior in the Princeton Neuroscience Institute.