The Cognitive And Neural Mechanism Of Facial Expression Working Memory

Emotion is an important aspect in our daily life, which has a close relationship with survival and development. Emotion-related objects can be better remembered. Different emotions will affect working memory processing and maintaining in different ways. Previous studies on visual working memory have been focusing on non-social stimulus such as color, shape, orientation. However, it is still unknown about how facial expressions information is encoded and maintained in visual working memory, and how different facial expressions affect working memory capacity and precision.In the present study, a series of experiments have been done to explore the relationship between facial expressions and visual working memory. The first experiment using face change-detection task along with ERP to investigate working memory capacity for emotional face stimuli. Participants were asked to detect the change of identity of three kinds of face expressions (happy, neutral and disgust). In the meanwhile, emotional information can be processed unconsciously. Results showed that although CD A component was identical to previous researches, N170 and showed that when working memory load is high, not neutral but emotional faces (happy, disgust) may be processed priority, which imply that cognitive resource was assigned to emotional stimuli first when it was constraint. The second experiment using continuous report paradigm to explore the visual working memory precision for facial expression. Participants were asked to use mouse to click the exactly face picture according to the cue information in the probe on a face wheel after a short period of delay. Results showed that there was no different on precision among the three kinds of facial expression (happy, neutral and fear) when visual working memory load is 1. However, when visual working memory load is 2, the precision of happy and neutral face declined while fearful face remain unchanged. The third experiment using continuous report paradigm along with ERP to explore the reason why different facial expression have different influence on visual working memory capacity and precision when working memory load is 2. The difference between high precision trials and low precision trials on N2pc component was conducted. Results showed that in the high precision trials group, cognitive resource was well controlled to suppress the influence of fearful face; but in the low precision trials group, fearful face took advantage of cognitive resource, leading to a bad performance for recalling happy face; and whether in the high precision trials group or in the low precision trials group, fearful face gained more attention, which was consist with experimentl and experiment2 about negative facial expression such as fearful face has a constant working memory precision.In summary, emotional face will occupy more cognitive resource result in processing priority when working memory load is high. Negative facial expression such as disgust face and fearful face grab more attention, keep its working memory precision at a high level. The present study provide a new perspective for facial expression memory. Future researches can evolved in new technology including fMRI, TCS, TMS to explore the neural mechanism of facial expression and visual working memory interaction.