Emotional flexibility has become a widely discussed topic in emotional psychology, clinical psychology, health psychology and other fields. Professor Zhou Renlai and his group from Beijing Key Lab of Applied Experimental Psychology, School of Psychology, Beijing Normal University (BNU) explored whether frontal electroencephalogram (EEG) lateralization can predict emotional flexibility. Frontal EEG activation during different emotion stimuli was measured. They identified the difference of frontal EEG lateralization could predict difference in emotional flexibility. Relative left lateralization was associated with flexible emotional responses, whereas relative right lateralization was associated with inflexible emotional responses. Their work, entitled "frontal EEG lateralization predicts individuals' emotional flexibility", was published in Science China Life Sciences.2014, Vol 44(6).

With increasingly intense competition in society, people may encounter all kinds of events related to the emotions in the life, study, and work. It is crucial that how people carry out the flexible responses according to the requirement of the situation and the needs of the individuals. The electroencephalogram (EEG) has an obvious predominance in emotional flexibility research. Left and right hemisphere prefrontal cortexes are involved in processing and regulating emotional responses in varying degrees. Thus, there is a close relationship between frontal EEG lateralization and emotional flexibility. Up to now, however, it is still not clear that whether frontal EEG lateralization is an indicator of emotional flexibility, and how frontal EEG lateralization can predict emotional flexibility.

Frontal EEG activation was measured during different emotion stimuli (e.g., neutral, cheerfulness, sadness, anger, fear, aversion). An emotion film paradigm was used to induce neutral, happy, sad, anger, fear, and aversive emotions. After presentation of each film clip, participants were then asked to rate the valence and motive intensity of each film clips on a scale from 1 (extremely negative or extremely withdrawal intensity) to 9 (extremely positive or extremely approach intensity). For the ratings results, happy films had the highest valence ratings, followed by the negative films (including sad, anger, and fear). However, happy and sad films had the higher motive intensity, followed by other films (including anger, aversive, and fear). The EEG results showed that activation pattern of emotional flexibility reflected the emotional motivation dimension, not the emotional valence dimension. Furthermore, relative left EEG lateralization individuals at rest had the trend of the left frontal active with approach-related emotions, and the trend of the right frontal active with withdrawal-related emotions. However, relative right EEG lateralization individuals at rest had no change for approach-related or withdrawal-related emotions. The results suggested that the difference of frontal EEG lateralization could predict different in emotional flexibility. Relative left lateralization was associated with flexible emotional responses, whereas relative right lateralization was associated with inflexible emotional responses.

On the basis of these findings, it would appear that those with greater relative right frontal activity showed a relative inability to regulate emotional reactions, such as depression or anxiety individuals. Thus, it is possible to improve the relative left EEG lateralization by training (e.g., mindfulness training), which can enhance emotional flexibility, and then relieve the level of depression or anxiety.