The Facial expressions are movements in the face caused by the numerous muscles supplied by the facial nerve that are attached each other and move the facial skin.

Surprisingly our face is as complicated as it appears to be and a highly differentiated part of our body, in fact, it is one of the most complex systems of signal in humans. Our face includes over 40 structurally and functionally autonomous muscles, each of which can be triggered independently of each of which can produce over 10000 expressions.

(Image Source: http://www.oscarfavorite.com/2013/03/lie-to-me.html)

All muscles in our body are connected by nerves, which route all the way into the spinal cord and to the brain. The nerve connection is bidirectional, i.e. the nerve is triggering muscle contractions based on signals from brain-to-muscle, and eventually communicates information on the current muscle state back into the brain.

For a fact, all facial muscles in our body are innervated by a single nerve which is also known as facial nerve. In medical terms, the facial nerve is also known as cranial nerve. This nerve emerges deep from within the brainstem, leaving the skull slightly below the ear, and branches off to all muscles just like a tree. Interestingly, the facial nerve is also connected with much younger motor regions in our neo-cortex; yes it’s called the neo as these areas are seen only in mammalian brains, and they primarily hold responsibility for facial muscle movements required for talking.

The brainstem and motor cortex are specifically the active indicators of whether the produced facial expression is involuntary or voluntary. While the brainstem controls involuntary expressions in our body that show up spontaneously, and the motor cortex is involved in consciously controlling the intentional facial expressions.

Well, it could be still a little confusing about how these fit the puzzle of emotions, we’ll tell you, the very same regions in the brainstem which trigger our facial expressions also control emotional processing and regulation. Some functional imaging studies (fMRI) have identified a specific region in the brainstem that is highly active when confronted with potential visual or audio threats, for instance, a looming shadow or a high-pitched scream from a horror movie; this could trigger the sensors from the right and left amygdala.

Know more about how and what controls the emotional arousal; stay tuned to our blogs on www.neuroconnect.in