Facial expressions arise from brain networks that encode slow, context-rich meaning and fast muscle control on different time scales, keeping smiles and threats socially precise.

For decades, scientists have mapped attention, memory, language, and reasoning to separate brain networks — yet one big mystery remained: why does the mind feel like a single, unified system?

Our sensory contact with external reality is limited by the narrow ranges that our sense organs can register. We can see only a small part of the electromagnetic spectrum mostly because Earth’s ...