Our facial expressions are our communication tool
Every day our face produces thousands of expressions. Some of them reflect what we actually feel, and some of them are meant to make the desired impression on other individuals. They have been developed by the millions of years of the evolution to become one of the most sophisticated communications tools. We can say much more with our facial expressions than with words, in a much shorter time. After Bell’s palsy, when various complications such as a crooked smile, synkinesis or contractures develop, our facial expressions change, making it more difficult to communicate our feelings and intentions to others.
In this article, we explain which two systems control our facial expression and how we sabotage ourselves by choosing one over the other.
The two systems that control our facial expressions
Our facial expressions can either be honest (based on how we really feel) or forced (when we want to make the desired expression even if we feel differently.) These two types of facial expressions are controlled from two distinctly different areas of the brain: the emotional center (limbic system) and the volitional center (motor cortex).
The limbic system – our “factory of emotions”
The limbic system is known as our “factory of emotions”. It works the same way in all animals, humans included. Once we experience an emotion, it is immediately reflected either by our facial expression, or by the body language, or most of the time, by both. It is an evolutionally much older formation that works the same way in all human beings. We can unmistakably recognize joy or surprise, curiosity or anxiety, anger or disgust by just looking at someone’s face, and it does not matter to which race or sex that person belongs.
The limbic system is capable of producing an extremely fine-tuned and highly differentiated control over facial muscles because we experience (and need to reflect) an extremely diverse spectrum of emotions.
The motor cortex – our volitional center
Motor cortex exerts a volitional control over our facial expressions. This ability developed in humans at the later stages of evolution, when personal interactions gained importance for the social status and the survival of an individual. We use this system to force certain expressions to our face either to make the desired impression or because our circumstances dictate so.
The control over facial movements by motor cortex is much coarser and much less nuanced than that of limbic. Very often we can distinguish a genuine smile from the forced one, and a real surprise from its artificial copy. We subconsciously notice the difference.
How does our brain choose which system to use for expressions?
Whenever we produce any facial expression, whether it is a spontaneous emotional reaction or a planned expression, our brain sends signals from both the limbic system and the motor cortex to the facial nerve. The nucleus of the facial nerve summates the signals arriving from both centers and our face reflects the result. We can, for example, suppress our joy if the smile in particular circumstances would be inappropriate. Or we can conceal our disappointment behind an artificial smile if the situation requires.
What happens to these two systems during Bell’s palsy?
Our volitional center becomes the cause of synkinesis
In many situations after Bell’s palsy, we engage only our motor cortex while trying to produce some facial movements. This happens because we want to consciously control the intensity of contraction signals. We keep trying to force our facial muscles into certain expressions. This can happen when we are standing in front of a mirror, trying to make the affected side produce at least something, or during conversations when we become conscious of our expressions and want to make sure that we can communicate a certain emotion or feeling.
Since we struggle to produce the intended expressions on the affected side, we keep trying harder and harder, forcing our brain to send ever stronger signals to our facial muscles without much result. This becomes a habit and leads to “habitual overdose” of volitional efforts. In the end, this causes synkinesis, mass movements and other complications.
Using the emotional center for natural facial expressions during Bell’s palsy
The intensity of emotional expressions depends only on the intensity of the experienced emotions and cannot be consciously controlled. This help to avoid developing the habit to constantly over-exaggerate the signals that we force our brain to send to our facial muscles. Our emotional center is much more finely tuned and knows better how to produce correct facial expressions.
This is one of the underlying principles that we use in our clinic during the rehabilitation – we teach your brain to “shut-off” the volitional center and use only the natural signals that arrive from the limbic system to help you produce facial expressions after Bell’s palsy.
– Alex Pashov
Crystal Touch Bell’s palsy clinic