Emotion Recognition Using Phase-Locking-Value Based Functional Brain Connections Within-Hemisphere and Cross-Hemisphere

Research in cognitive neuroscience has found emotion-induced distinct cognitive variances between the left and right hemispheres of the brain. In this work, we follow up on this idea by using Phase-Locking Value (PLV) to investigate the EEG based hemispherical brain connections for emotion recognition task. Here, PLV features are extracted for two scenarios: Within-hemisphere and Cross-hemisphere, which are further selected using maximum relevance-minimum redundancy (mRmR) and chi-square test mechanisms. By making use of machine learning (ML) classifiers, we have evaluated the results for dimensional model of emotions through making binary classification on valence, arousal and dominance scales, across four frequency bands (theta, alpha, beta and gamma). We achieved the highest accuracies for gamma band when assessed with mRmR feature selection. KNN classifier is most effective among other ML classifiers at this task, and achieves the best accuracy of 79.4%, 79.6%, and 79.1% in case of cross-hemisphere PLVs for valence, arousal, and dominance respectively. Additionally, we find that cross-hemispherical connections are better at predictions on emotion recognition than within-hemispherical ones, albeit only slightly.