EEG alpha band functional connectivity reveals distinct cortical dynamics for overt and covert emotional face processing

Abstract

Current knowledge regarding how the focus of our attention during face processing influences neural responses largely comes from neuroimaging studies reporting on regional brain activations. The present study was designed to add novel insights to this research by studying how attention can differentially impact the way cortical regions interact during emotional face processing. High-density electroencephalogram was recorded in a sample of fifty-two healthy participants during an emotional face processing task. The task required participants to either attend to the expressions (i.e., overt processing) or attend to a perceptual distractor, which rendered the expressions task-irrelevant (i.e., covert processing). Functional connectivity in the alpha band was estimated in source space and modeled using graph theory to quantify whole-brain integration and segregation. Results revealed that overt processing of facial expressions is linked to reduced cortical segregation and increased cortical integration, this latter specifically for negative expressions of fear and sadness. Furthermore, we observed increased communication efficiency during overt processing of negative expressions between the core and the extended face processing systems. Overall, these findings reveal that attention makes the interaction among the nodes involved in face processing more efficient, also uncovering a connectivity signature of the prioritized processing mechanism of negative expressions, that is an increased cross-communication within the nodes of the face processing network.

Navigating Pubertal Goldilocks: The Optimal Pace for Hierarchical Brain Organization

“…The relevance of the alpha band in resting state studies is further emphasized by more recent findings demonstrating the overlap between fMRI‐based large‐scale networks and resting state connectivity in the alpha band. [ 119 , 120 ] It might also be relevant to mention that oscillations below the alpha range tend to engage the entire cortex and mostly contribute to long‐range temporal integration, [ 121 ] while oscillations beyond the alpha range tend to be more local, preventing a meaningful analysis of global hierarchical brain organization. However, for interested readers, the entropy production results of delta, theta, beta, and sigma bands on the OSF website (under Supporting Information) have been included.…”