Simon van Rysewyk 'think and wonder, wonder and think' A neurobehavioralpolyvagal theory of pain facial expression June 17, 2014 in Brain , cerebral cortex , Chronic Pain , Clinical Pain , Consciousness , Emotion , Emotions , Empathy , Facial Expression , Feelings , Human Face , Mind , Neuroscience , Pain , phenomenal consciousness , Phenomenology , Philosophy , Psychology , Research , Science , Simon van Rysewyk , Thinking , Type Identity Theory , Writing | Tags: brain , consciousness , emotion , empathy , facial expression , human face , human nature , imitation , mind , mindbrain identity theory , neuroscience , pain , philosophy , research , science , simon van rysewyk , thinking , writing (Edit ) The personal experience of pain produces a reliable effect on facial behavior in humans and in nonhuman mammals. Why should pain have a face? What is it for? I will attempt to head towards answering this question by invoking a theoretical framework: polyvagal theory (Porges, 2001, 2006). 1 Polyvagal Theory According to polyvagal theory (Porges, 2001, 2006), evolution of neural control within the autonomic nervous system (ANS) has tracked three stages, each revealing a specific behavior, and a specific function: In the first stage, the ancient unmyelinated visceral vagus nerve that enables digestion could respond to danger and pain only by reducing metabolic output and producing immobilization behaviors. In the second stage, the sympathetic nervous system (SNS) made it possible to increase metabolic activity and inhibit the visceral vagus nerve, thus allowing fight/flight behaviors following perceived threat or pain. The third stage, which is uniquely mammalian, involves a myelinated vagus that can rapidly control cardiac and bronchi output to enable spontaneous interaction (i.e., engagement or disengagement) with the environment. The interaction of the autonomic nervous system (ANS) with the hypothalamopituitaryadrenal (HPA) axis, nervous and immune systems change to maximize response to stressors such as nociception. During nociception, the ANS operates together with nervous, endocrine and immune systems to produce stress (Chapman et al. 2008; Porges, 2001, 2006). In terms of polyvagal theory, pain facial expression is a dynamic autonomic response caused by noxious signaling. In terms of polyvagaltype identity mechanistic theory pain facial expression is a type of behavior that is identical to a type of neurophysiological mechanism; namely, the phylogenetically recent brainheartface mechanism. The expansion of cortex in the third stage increased innervation and neural control of the mammalian face: upper face innervation is bilateral and arises from the supplementary motor area (M2) and the rostral cingulate motor area (M3). Lower face innervation is contralateral and arises from primary motor cortex (M1), ventral lateral premotor cortex, and the caudal cingulate motor cortex (M4) (Morecraft et al. 2004). Human pain facial movements of the eyebrows and upper lip are type identical with negative emotional aspects of pain and activation of M1, M2, M3, whereas facial movements around the eyes are type identical with somatosensory aspects of pain, and activation of M2 and M3 (Kunz et al. 2011). Thus, evolution of cranial anatomy enabled a highly integrated facial representation of the multidimensional experience of pain. 2 Why Pain Should Have a Face