Particle.news
Download on the App Store

Study in Macaques Maps Unified Brain Network Orchestrating Facial Expressions

Researchers say the cortex prepares gestures in advance using fast motor codes alongside slower stable signals.

Overview

  • The Science study identifies a distributed facial motor network spanning cingulate motor, primary and ventral premotor, and somatosensory cortices with direct access to facial muscles.
  • Findings show medial and lateral regions both encode voluntary and emotional gestures, overturning the long-held segregation model.
  • Neural activity unfolds on distinct timescales, with rapid dynamics in lateral motor areas and slower, sustained patterns in medial cortex.
  • Signals predicting threatening, lipsmacking, and chewing gestures emerge before visible movement in fMRI-guided recordings from behaving macaques.
  • A related PNAS analysis indicates these areas operate as a single, movement-dependent sensorimotor network, with translational possibilities still prospective for clinical use and brain–machine interfaces.