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Resting-state fluctuations are ubiquitous and widely studied phenomena of the human brain, yet we are largely in the dark regarding their function in human cognition. Here we examined the hypothesis that resting-state fluctuations underlie the generation of free and creative human behaviors. In our experiment, participants were asked to perform three voluntary verbal tasks: a verbal fluency task, a verbal creativity task, and a divergent thinking task, during functional magnetic resonance imaging scanning. Blood oxygenation level dependent (BOLD)-activity during these tasks was contrasted with a control- deterministic verbal task, in which the behavior was fully determined by external stimuli. Our results reveal that all voluntary verbal-generation responses displayed a gradual anticipatory buildup that preceded the deterministic control-related responses. Critically, the time–frequency dynamics of these anticipatory buildups were significantly correlated with resting-state fluctuations’ dynamics. These correlations were not a general BOLD-related or verbal-response related result, as they were not found during the externally determined verbal control condition. Furthermore, they were located in brain regions known to be involved in language production, specifically the left inferior frontal gyrus. These results suggest a common function of resting-state fluctuations as the neural mechanism underlying the generation of free and creative behaviors in the human cortex.

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The magnitude of neuronal activation is commonly considered a critical factor for conscious perception of visual content. However, this dogma contrasts with the phenomenon of rapid adaptation, in which the magnitude of neuronal activation drops dramatically in a rapid manner, while the visual stimulus and the conscious experience it elicits remain stable. Here we report that the profiles of multi-site activation patterns and their relational geometry, i.e. the similarity distances between activation patterns, as revealed using iEEG recordings, are sustained during extended stimulation despite the major magnitude decrease. These results are compatible with the hypothesis that conscious perceptual content is associated with the neuronal pattern profiles and their similarity distances, rather than by the overall activation magnitude, in human visual cortex.

Internally generated (free) ideas and creative thoughts constitute a fundamentally important aspect of the human experience, yet the neuronal mechanism driving these behaviors remains elusive. Here we examined the hypothesis that the common mechanism underlying free verbal behaviors is the ultra-slow activity fluctuations (termed "resting state fluctuations") that emerge spontaneously in the human brain.In our experiment, participants were asked to perform three voluntary verbal tasks: a verbal fluency task, a verbal creativity task (alternative uses of everyday objects) and a divergent thinking task (instances of common concepts), during fMRI scanning. BOLD-activity during these tasks was contrasted with a controldeterministic verbal task, in which the behavior was fully determined by external stimuli. Our results reveal that in all three voluntary tasks, the verbal-generation responses displayed a gradual anticipatory buildup that preceded the deterministic control-related responses by ~2 seconds. Importantly, variance analysis ruled out a time-jittered step-function response confound. Critically, the waveforms of the anticipatory buildups, as reflected in their time-frequency dynamics, were significantly correlated to the dynamics of resting state fluctuations, measured during a rest period prior to the tasks. Specifically, the amplitude of low frequency fluctuations (fALFF) of the resting state time-course and the voluntary verbal responses in the left inferior frontal gyrus (LH IFG), a central hub engaged in these tasks, were correlated across individual participants. This correlation was not a general BOLD-related or verbal-response related result, as it was not found during the externally-determined verbal control condition. Furthermore, it was specific to brain regions known to be involved in language production. These results indicate that the slow buildup preceding voluntary behaviors is linked to resting state fluctuations. Thus, these ubiquitous brain fluctuations may constitute a common neural mechanism underlying the generation of free and creative behaviors in the human brain.