Unconscious Feelings Of Surprise Facial Expression Brain Function

Facial expressions are significant biological indicators of emotion. We can realize one's emotion state according to the facial expression. So far, the investigation about the perception of facial expressions has been an important field of cognitive neuroscience, and the studies are done on two levels, conscious and unconscious. Because the unconscious information has unforgiving influence to human's brain and actions, it's very important to study the unconscious perception of facial expressions. As one of the six basic emotions, the surprised facial expression has been neglected in recent studies. Therefore, this paper will study the neural mechanism of the unconscious perception of surprised facial expression.This paper mainly focused on the study of unconscious perception of surprised facial expression based on functional magnetic resonance imaging (fMRI), analyzed the brain activation during unconscious perception of surprised facial expression, and used Psychophysiological interaction (PPI) to explore the functional connectivity of the brain during unconscious perception of surprised facial expression. Some aspects of this dissertation have been put forward:1. Study of the brain activation during unconscious perception of surprised facial expression. An unconscious perception of several emotional facial expressions experiment based on fMRI was designed, including surprised, happiness and neutral faces, in order to study the surprised faces. Then the SPM software based on General Linear Model (GLM) were employed to analyze data. The results showed that during unconscious perception of surprised facial expression, brain activation exists mainly in the right parahippocampal gyrus, left fusiform gyrus, right amygdala, bilateral inferior occipital gyrus, middle occipital gyrus and temporal cortex. Additionally, the key role of the right parahippocampal gyrus, left fusiform gyrus and right superior temporal gyrus during unconscious perception of surprised facial expression has been observed.2. Study of the connectivity of brain during unconscious perception of surprised facial expression. Based on the experiment mentioned above, we used Psychophysiological interaction (PPI) to explore the connectivity of brain during unconscious perception of surprised facial expression. Selecting the right parahippocampal gyrus as the source region, the results showed the connectivity between the source region and four regions, including right amygdala, left fusiform gyrus ,bilateral inferior occipital gyrus and right superior temporal gyrus. Further, we found the change of the connectivity strength between the right parahippocampal gyrus and the left fusiform gyrus and the right superior temporal gyrus can give rise to the ability change of unconscious perception of surprised facial expression.