Alpha-Beta oscillations implement inhibition of the ventral attention network during an attention task

Abstract

Selective attention is a crucial mechanism that allows us to focus on relevant information while ignoring irrelevant information. Although extensive literature has proposed that alpha oscillations (7-14 Hz) suppress distractor processing, recent studies have questioned this role. In this magnetoencephalography (MEG) study, we used a modified Stroop task to investigate whether (1) alpha oscillations are associated with functional inhibition in higher-order visual regions and the ventral attention network (VAN), and (2) alpha phase adjusts in anticipation of relevant and irrelevant stimuli. We found no significant increase in pre-stimulus alpha power or phase adjustment over higher-order visual regions in the attend-color condition, consistent with the absence of a behavioral Stroop effect. However, we observed elevated alpha-beta power (10-20 Hz) in the VAN during both attend-color and attend-word conditions compared to control conditions, occurring before stimulus onset. Higher alpha-beta power in the right temporo-parietal junction correlated with faster reaction times, suggesting that inhibition of this network region facilitates task performance. This alpha-beta modulation in the VAN may represent a general mechanism for resisting distraction, preventing attentional capture by irrelevant information regardless of task condition. Additionally, we found enhanced theta power (4 Hz) over the VAN and left medial frontal gyrus (part of the cognitive control network) in both experimental conditions. Theta power correlated with improved reaction times across these regions. Furthermore, theta activity in the left medial frontal gyrus synchronized with VAN nodes, potentially indicating cross-network interaction between cognitive control and attention systems.