Developing A Non-Human Primate Model To Dissect The Neural Mechanism Of Facial Emotion Processing

Facial emotion recognition is a cornerstone of social cognition, vital for interpreting social cues and fostering communication. Despite extensive research in human subjects, the neural mechanisms underlying this process remain incompletely understood. This thesis investigates these mechanisms using a non-human primate model to provide deeper insights into the neural circuitry involved in facial emotion processing. We embarked on a comparative analysis of facial emotion recognition between humans and rhesus macaques. Using a carefully curated set of facial expression images from the Montreal Set of Facial Displays of Emotion (MSFDE), we designed a series of binary emotion discrimination tasks. Our innovative approach involved detailed behavioral metrics that revealed significant parallels in emotion recognition patterns between the two species. These findings highlight the macaques’ potential as a robust model for studying human-like facial emotion recognition. Building on these behavioral insights, the second phase of our research delved into the neural underpinnings of this cognitive process. We conducted large-scale, chronic multi-electrode recordings in the inferior temporal (IT) cortex of rhesus macaques. By mapping the neural activity associated with the classification of different facial emotions, we uncovered specific neural markers that correlate strongly with behavioral performance. These neural signatures provide compelling evidence for the role of the IT cortex in processing complex emotional cues. Our findings bridge the gap between behavioral and neural perspectives on facial emotion recognition, offering a comprehensive understanding of the underlying mechanisms. This research not only underscores the evolutionary continuity of social cognition across primate species but also sets the stage for future explorations into the neural basis of emotion processing. The integration of behavioral analysis with advanced neural recording techniques presents a powerful framework for advancing our knowledge of social cognition and its disorders.