Scientists at Rockefeller University used fMRI while macaque monkeys produced facial movements. They identified cortical zones that access facial muscles: a medial cingulate motor area, lateral primary and premotor areas, and the primary somatosensory cortex. Together these areas form a facial motor network that controls gestures.
The researchers elicited three movements — threatening, lipsmacking and chewing — using live social interaction, videos and controlled digital avatars. They found that all cortical regions participated in every gesture type, but each region showed different timing. Lateral areas displayed fast dynamics on the order of milliseconds, whereas medial areas showed slower, more sustained activity.
Related analysis of the same data showed these regions form an interconnected sensorimotor network that adapts coordination for different movements. The team plans further work on perception, emotional control areas and clinical applications.
Difficult words
- cortical — relating to the brain's outer layer
- medial — toward the middle of the body or brain
- lateral — toward the side, away from the middle
- elicit — to cause something to happen or appearelicited
- dynamics — patterns of change or activity over time
- sustained — continuous, lasting for a long time
- sensorimotor — involving both sensation and movement control
- gesture — a movement of the body or face to communicategestures
- perception — the process of becoming aware through senses
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Discussion questions
- How could studying facial motor networks in monkeys help clinical applications for humans?
- Which of the three movements (threatening, lipsmacking, chewing) do you think needs the fastest brain timing, and why?
- How might controlled digital avatars be useful when researchers study social interactions and facial gestures?
