Facial expression responsible for controlling the expression differ in each case. Voluntary facial expressions are often socially conditioned and follow a cortical route in the brain. Conversely, involuntary facial expressions are believed to be innate and follow a subcortical route in the brain. Facial recognition is often an emotional experience for the brain and the amygdala is highly involved in the recognition process. The eyes are often viewed as important features of facial expressions. Aspects such as blinking rate can possibly be used to indicate whether a person is nervous or whether he or she is lying. Also, eye contact is considered
Forensic facial reconstruction of facial features, and other available reconstructions. These computer approximations are usually most effective in victim identification because they do not appear too artificial. This method has been adapted by the National Center for Missing & Exploited Children, which uses this method often to show approximations of an unidentified decedent to release to the public in hopes to identify the subject. Superimposition is a technique that is sometimes included among the methods of forensic facial reconstruction. It is not always included as a technique because investigators must already have some kind of knowledge about the identity of the skeletal remains