Prefrontal cortex hemodynamic activity in healthy and mild depression subjects during emotion-expressing motions: an fNIRS study

Abstract

Emotion-expressing motions, such as clapping, sighing or laughing, have been found to affect and regulate our mood. Specifically, depending on the type of emotion-expression motions, they are known to induce either positive or negative emotion. However, the mechanism of how executing those motions affect the brain is currently unknown. This study aims to investigate the underlying brain activities in healthy and mild depression subjects during emotion-expressing tasks. The focus of our study lies on the prefrontal cortex (PFC) hemodynamic activity changes induced by two different set of movement tasks, which relate to either positive or negative emotions. Subjects were asked to do a set of motions that is known to express positive or negative emotions, while having the changes in their PFC hemodynamics recorded using functional Near Infrared Spectroscopy (fNIRS). We preprocessed, removed motion artifacts, and analyzed the fNIRS data using general linear model (GLM) with short-separation regressors. We discovered that emotion-expressing movement tasks induced different activations in the PFC of healthy and mild depression subjects. The left hemisphere of mild depression subjects’ PFC showed inhibited activity. This research provides a starting point to reveal the emotional connection between brain-body, which might provide future in-depth understanding of our emotional responses as well as engender future therapies of mood disorders.