Development of Facial Expression Recognition Following Extended Blindness: the Importance of Motion

Despite her still poor visual acuity and minimal visual experience, a 2–3 month old baby will reliably respond to facial expressions, smiling back at her caretaker or older sibling. But what if that same baby had been deprived of her early visual experience? We describe the development of facial expression recognition in a unique population: children who had been treated for bilateral congenital blindness several years after birth (ages 6–22 at treatment). We find that within the first few months after treatment, these children fail to demonstrate substantial improvements in a basic expression recognition task, but thereafter begin to show significant progress. Specifically, when we probe the children’s ability to recognize expressions based on dynamic versus static information, we find that their performance on the dynamic task improves much quicker and surpasses their ability to recognize expressions from static images. Recognition of static facial expressions, on the other hand, continues to fall significantly short of control levels, even years after treatment. Our findings support the important role of motion for early visual learning and binding of visual features. Furthermore, our findings suggest that dynamic information continues to be important for learning and progressively improving the recognition of facial expressions even well after treatment, suggesting a prolonged and robust reliance on motion information late in the visual developmental trajectory.