Automatic orofacial behaviors remap within cortical substrates for voluntary motor control in freely moving primates

In two freely moving macaques, cortical recordings across 640 ventral motor and premotor sites show yawning is represented by 169 LFP–spike coupled locations and 95 neurons.

• Why it matters: Orofacial actions are often attributed to conserved subcortical circuits, but their context-dependent voluntary modulation in primates suggests cortical contributions are being missed.
• What they did: The team wirelessly recorded from 640 sites while macaques performed yawning, threat, bite, and drink, then analyzed LFP–spike coupling, beta suppression and high-gamma enhancement, single-neuron tuning, and head-free intracortical microstimulation.
• The result: Yawn-related units showed early beta-band suppression followed by high-gamma power enhancement, encoded yawning (mostly medium-sized pyramidal cells), and microstimulation preferentially evoked localized mouth and face movements, supporting a causal cortical role in orofacial motor control.

AI summary of the abstract · may contain errors · not medical advice · read the paper.