Scientists trace facial gestures back to their source. before a smile appears, the brain has already decided

Every time we smile, grimace, or flash a quick look of surprise, it feels effortless, but the brain is quietly coordinating an intricate performance. This study shows that facial gestures aren’t controlled by two separate “systems” (one for deliberate expressions and one for emotional ones), as scientists long assumed. Instead, multiple face-control regions in the brain work together, using different kinds of signals: some are fast and shifting, like real-time choreography, while others are steadier, like a held intention. Remarkably, these brain patterns appear before the face even moves, meaning the brain starts preparing a gesture in advance, shaping it not just as a movement, but as a socially meaningful message. That matters because facial expressions are one of our most powerful tools for communication and understanding how the brain builds them helps explain what can go wrong after brain injury or in conditions that affect social signaling, This may eventually guide new ways to restore or interpret facial communication when it’s lost.

When someone smiles politely, flashes a grin of recognition, or tightens their lips in disapproval, the movement is tiny, but the message can be enormous. Facial gestures are among the most powerful forms of communication in primate societies, delivering emotion, intention, and social meaning in fractions of a second.

Now, a new study published in Science uncovers how the brain prepares and produces these gestures through a temporally organized hierarchy of neural “codes,” including signals that appear well before movement begins.

The research was led by Prof. Winrich A. Freiwald of The Rockefeller University in New York and Prof. Yifat Prut of ELSC at Hebrew University working with Dr. Geena Ianni and Dr. Yuriria Vázquez from The Rockefeller University.

For decades, neuroscience has leaned on a tidy division: lateral cortical areas in the frontal lobe controls deliberate, voluntary facial movements, while the medial areas governs emotional expressions. This view was shaped in part by clinical evidence from individuals with focal brain lesions.

But by directly measuring activity from individual neurons across both cortical regions, the researchers found something striking: both regions encode both voluntary and emotional gestures and they do so in ways that are distinguishable well before any visible facial movement occurs.

In other words, facial communication appears to be orchestrated not by two separate systems, but by a continuous neural hierarchy, where different regions contribute information at different time scales, some fast-changing and dynamic, others stable and sustained.

Dynamic vs. Stable: Two Neural Languages Working Together

The team discovered that the brain uses area-specific timing patterns that form a continuum:

• Dynamic neural activity reflects the rapid unfolding of facial motion, like the shifting muscle choreography involved in an expression.
• Stable neural activity functions more like a sustained “intent” or “context” signal, persisting in time to support socially appropriate output.

Together, these activity patterns allow the brain to generate coherent facial gestures that match the context: deliberate or spontaneous, socially calibrated, and communication-ready.

Why This Matters

Facial gestures are not just physical movements. They are social actions, and the brain treats them as such.

This discovery offers a new framework for understanding:

• How facial gestures are coordinated in real time
• How communication-related motor control is structured in the brain
• What may go wrong in disorders where facial signalling is disrupted—whether through neurological injury or conditions affecting social communication

And it reframes facial expression as something more sophisticated than a reflex or a simple decision: it is the product of a coordinated neural hierarchy that bridges emotion, intention, and action.

By showing that multiple brain regions work in parallel, each contributing different timing-based codes, the study opens new pathways for exploring how the brain produces socially meaningful behavior.

“Facial gestures may look effortless,” the researchers note, “but the neural machinery behind them is remarkably structured and begins preparing for communication well before movement even starts.”