Amygdala lesions eliminate viewing preferences for faces in rhesus monkeys

Significance The primate brain is specialized for social interaction, and a complex network of brain regions supports this important function. Face perception is central to social development, and both humans and nonhuman primates exhibit a spontaneous viewing preference for faces. This shared involuntary response underscores the importance of faces in the earliest stages of cognitive development, yet its neural basis is not well understood. Here we report that bilateral amygdala lesions in rhesus monkeys eliminate the robust viewing preference for both real faces and illusory faces. This demonstrates a fundamental role for the amygdala in guiding eye movements toward face stimuli, a critical behavior for normal social development and social interaction.