Frontal midline theta reduction during attentional reconfiguration links local cortical dynamics to network-level connectivity changes.
TL;DR
It is suggested that transient Fmθ reduction during attentional reconfiguration reflects at least two partially dissociable processes: θ-band connectivity changes consistent with network-level reconfiguration associated with attentional reconfiguration in general, and local cortical dynamics selectively related to spatial information processing.
Abstract
Attentional reconfiguration during transitions between task contexts induces a transient reduction of frontal midline theta (Fmθ), a well-established neural marker of focused attention. However, it remains unclear whether this transient reduction reflects changes in local cortical activity associated with specific visual information processing or a more general reorganization of network-level connectivity. Thirty-six healthy young adults performed a rule-switching 2-back task that required attentional shifts between color-based and position-based processing. Electroencephalography was recorded using a 19-channel system and we compared changes in power spectral density, current source density, and lagged linear functional connectivity between epochs immediately before and after attentional reconfiguration using exact low-resolution electromagnetic tomography technique. Statistical analyses were conducted using permutation-based non-parametric methods. Transient reductions in Fmθ power and the number of Fmθ-positive epochs were consistently observed across both rule-switching patterns. In contrast, α band activity showed condition-dependent spatial modulation: parietal α suppression emerged selectively during shifts toward spatial processing, whereas occipital α suppression was observed during shifts toward color processing. Moreover, Fmθ reduction was significantly associated with parietal (but not occipital) α suppression. Connectivity analysis revealed robust increases in long-range θ-band coordination following attentional reconfiguration across conditions. These findings suggest that transient Fmθ reduction during attentional reconfiguration reflects at least two partially dissociable processes: θ-band connectivity changes consistent with network-level reconfiguration associated with attentional reconfiguration in general, and local cortical dynamics selectively related to spatial information processing.