Nature Communications
July 18, 2016
Erez Simony, Christopher J Honey, Janice Chen et al.
689 citations
The default mode network (DMN) reconfigures moment by moment to encode information about a changing environment, as shown by a new method called inter-subject functional correlation (ISFC). ISFC isolates stimulus-dependent correlations between brains exposed to the same stimulus, separating them from intrinsic neural processes and noise. In an fMRI experiment, subjects listened to an auditory narrative or temporally scrambled versions. ISFC revealed DMN correlation patterns locked to each narrative segment and specific to its meaning. These patterns were highly replicable across groups, and DMN coupling strength predicted memory of narrative segments, linking brain network dynamics to stimulus features and behavior.
Current biology : CB
July 2, 2026
Youngjai Park, Younghwa Cha, Hyoungkyu Kim et al.
The human brain's information flow alternates between two dominant modes roughly every 200 milliseconds: a top-down mode where anterior brain regions drive posterior activity, and a bottom-up mode with reverse directionality. These sub-second alternations are most prominent during wakefulness, gradually diminish under anesthesia, and show pathological imbalance in attention-deficit/hyperactivity disorder (ADHD). Simultaneous EEG-fMRI recordings reveal that top-down dynamics coincide with increased activity in higher-order cognitive networks, while bottom-up dynamics correspond to heightened sensory network activity. A connectome-based coupled-oscillator model reproduces these transitions, suggesting they emerge naturally from structural connectivity. Relative phase analysis (RPA) enables tracking these whole-brain dynamics with millisecond precision in real time from electroencephalography.
bioRxiv : the preprint server for biology
March 28, 2025
Youngjai Park, Younghwa Cha, Hyoungkyu Kim et al.
preprint
The human brain shifts between two directional modes on a sub-second timescale: a top-down mode where anterior regions drive posterior activity and a bottom-up mode with reverse directionality. These shifts are most distinct during full consciousness and become less pronounced as awareness fades. Simultaneous EEG-fMRI recordings show the top-down mode coincides with higher-order cognitive network activity, while the bottom-up mode aligns with sensory system activity. An inattentive ADHD cohort exhibited imbalances in these transition dynamics compared to typically developing individuals. A coupled-oscillator model of the structural brain network reproduced these patterns, suggesting they arise naturally from inter-regional neural interactions.