Facial expressions may appear spontaneous, but new research shows the brain begins preparing them long before the face actually moves.
Every time we smile or make a facial expression, it often feels instant and effortless. A long-held assumption has been that facial expressions are generated and controlled by two separate “systems”—one for deliberate expressions and another for emotional ones.
However, new findings reveal that the brain prepares facial gestures well before a person actually makes an expression. The research, which appeared in Science, was led by Prof. Winrich A. Freiwald of The Rockefeller University, along with colleagues Prof. Yifat Prut of the Hebrew University of Jerusalem, Dr. Geena Ianni, and Dr. Yuriria Vázquez.
“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.” In their study, the team recorded activity from individual neurons across both medial and lateral cortical regions involved in facial control.
The Secret World of Facial Movement
Voluntary facial movements were previously thought to be controlled by lateral regions of the frontal cortex, while emotional expressions were believed to originate in medial regions. These ideas were shaped by early clinical observations of brain injuries, in which one type of expression could be impaired while the other remained intact.
What the team behind the recent research found was striking. Their observations showed that both regions encode emotional and voluntary facial gestures before any noticeable movement occurs. In other words, the brain doesn’t wait for a conscious decision before moving the face; instead, it begins preparing the gesture in advance, encoding not only the mechanics of motion but also its social intent.
The researchers further found that facial expressions are produced within what they describe as a “neural hierarchy” that uses distinct “languages” of brain activity. One changes rapidly as an expression unfolds, while the other remains stable over time, reflecting intention, context, or social appropriateness.
These signals are distributed across multiple cortical regions, creating a continuum rather than a split system. Together, they allow the brain to generate facial gestures that are fluid, context-aware, and socially meaningful—ranging from a polite smile to a spontaneous grin or a look of disapproval.
A smile, after all, is rarely just a movement. It is often tied to an underlying emotional state and can signal friendliness, irony, recognition, or restraint, depending on the situation. Accordingly, the brain appears to understand that intent, even before our faces reflect how we feel.
By recording activity from individual neurons across both medial and lateral cortical regions involved in facial control, the team captured real-time neural signals at a level of detail not previously available. Compared to earlier imaging studies, which suggest a simple division between voluntary and emotional expressions, the new research indicates that a hierarchy of brain activity prepares expressions well before movement begins.
Why does this matter? Facial gestures are among our most powerful tools for social communication and connection. Understanding how the brain constructs them helps explain what happens when this system breaks down—such as after brain injury or in conditions that disrupt social signaling.
In short, this new research provides scientists with a new way to view facial expression not as a simple reflex, but as a carefully prepared social behavior, coordinated across multiple brain regions to link motion, intention, and action.
The recent paper, “Facial gestures are enacted through a cortical hierarchy of dynamic and stable codes,” appeared in Science.
Chrissy Newton is a PR professional and the founder of VOCAB Communications. She currently appears on The Discovery Channel and Max and hosts the Rebelliously Curious podcast, which can be found on YouTube and on all audio podcast streaming platforms. Follow her on X: @ChrissyNewton, Instagram: @BeingChrissyNewton, and chrissynewton.com. To contact Chrissy with a story, please email chrissy @ thedebrief.org.