Humans beings are persons and organisms

Sculpture by Fabio Viale

As organisms, human beings interact with the world and each other through causal mechanisms that control us and every other physical thing. As persons, we act in the world through our thoughts, emotions, attitudes, or desires.

Accordingly, human beings are describable in two distinct, but complementary ways: in terms of the way the world is, through scientific descriptions of the causal mechanisms and laws that explain physical things, or, in terms of the way the world seems, through descriptions of personal experiences and meanings.

One or the other way of describing human beings comes into focus depending on the questions we ask about ourselves or the world. The features of personal experience—thought, feeling, speech and action—are amenable to standard scientific explanation as specific changes in the body. Traditionally, scientific research has had much to say about the physical nature of pain, but much less about the personal experience or meaning of pain. Indeed, the meaning of pain remains a blind spot in knowledge.


A description of a human being as a person means that there is a way of understanding of human beings in which personal experience and meaning, rather than physical causation alone, is needed to answer the question, “What is happening?”

Human persons can distinguish between how things are in the world and how things seem to me. I can recognise within myself a perspective or point of view on the world and identify it as belonging to me. Every person has such a unique perspective; this is partly what it means to be a person rather than a physical thing. In contrast, a scientific description of the world does not presuppose any personal point of view. Physical science does not use words like “I”, “here,” or “now”. Does this mean that “persons” are unobservable to standard quantitative science?

Possibly. Imagine a complete explanation of pain according to the final neurophysiology of pain—whatever it turns out to be. Such an explanation of pain would, to put it very crudely, accurately map specific neurophysiological changes in physical parts in the living human organism and all their true causal interactions across time. However invaluable such an explanation would be to pain medicine, it could not describe the way pain seems to the person who experiences it, for which of the physical objects described in this explanation is me with pain, here, now? Immediate pain always seems a certain way to persons, and this “seeming” determines the experience of the person with pain. In describing personal pain, human beings use language with other meanings than the language used in neurophysiology. The final neurophysiological explanation of pain therefore could explain only one dimension of pain in human beings—the physical dimension—in language that could not capture the personal experience, burden, or meaning of pain.


A philosophical assumption of neurophysiology is that a person is identical with his or her body. Person and body are one and the same thing. In terms of personal experience, however, the identity between person and body escapes personal understanding. For example, when I feel a pain, there is no information or evidence, or nothing that I could discover about my body subsequent to the experience of pain, that could demonstrate it to be false. When I feel a pain, I simply know that I am in pain.

In person to person interactions, we commonly respond to each other as though we are not identical with the human body, but in a compelling sense operating “through” the body, which seems to be a vehicle of thought, emotion, pain or suffering. We feel that each person we encounter in the world is a unique perspective that is not the body, but the “self”, which peers out through the face. The human face is the social instrument of persons. In seeking to understand you, or adjust how the world or your experience seems to you, I interact with you through your embodied perspective.

In pain experience, it is my loss of personal control over my body, and its dominion over me, that create the compelling sense, for me and for others, of an “incarnate” person. Pain imposes a significant vulnerability on persons: the vulnerability of a free person who is overwhelmed in his or her body by the presence of pain. This can make the person, and the person’s significant others, feel answerable for what he or she experiences.


A neurobehavioral-polyvagal theory of pain facial expression

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

In clinical and experimental settings, the pain face is observed to rapidly appear following noxious stimulation, and diminish concurrent with cessation of the noxious stimulus, or when analgesics are administered (e.g., Craig & Patrick, 1985). The brain-heart-face mechanism is an integrated system with both a somatomotor part controlling the striated facial muscles and a visceromotor part controlling the heart through a myelinated vagus nerve (Porges, 2001, 2006). When the vagal tone to the cardiac pacemaker is high, the myelinated vagus acts as a brake or restraint limiting heart rate. Rapid inhibition and disinhibition of vagal tone to the heart supports the rapid mobilization of facial muscles and formation of the pain face concurrent with pain onset. In humans and nonhuman mammals, the main vagal inhibitory pathways in the myelinated vagus originate in the nucleus ambiguus.

The vagal brake supports the low-metabolic requirements involved in the rapidly appearing and disappearing pain face. Withdrawal of the vagal brake is strongly correlated with the rapid appearance of the pain face; reinstatement of the vagal brake is strongly correlated with the rapid diminishing of the pain face. These correlations are not unique to pain facial expression; similar relationships hold with regard to the vagal brake and the timing and duration of aversive, but non-noxious emotional facial expressions (e.g., Pu et al. 2010), and positive emotional facial expressions (e.g., Kok & Fredrickson, 2010).

In terms of the function of rapid pain face onset and offset, the vagal brake makes it possible for the individual in pain to quickly disengage from source of wounding and pain, concurrent with the rapid appearance or diminishing of pain facial expression, which may offer temporary access to additional metabolic resources to aid healing, recovery and self-soothing behaviors, with likely involvement from care givers.

Concerning aid from others, the vagal brake reliably maps onto specific interaction types observed in mammalian pain events. In pain events comprising the individual in pain and care givers, mammalian behavior is typed according to interpersonal communication through facial expressions, vocalizations, head and hand gestures (Hadjistavropoulos et al. 2011; Porges, 2001, 2006; Williams, 2002). A relevant feature is the rapid ‘switching’ of temporary engagement to temporary disengagement behaviors between the individual in pain and care givers. This interaction type may involve care givers speaking to the one in pain, and then quickly switching to listening; for the one in pain, looking into the face of the care giver, and then quickly switching to vocalizing (Craig et al. 2011; Hadjistavropoulos et al. 2011; Porges, 2001, 2006; Williams, 2002). The brain-heart-face mechanism thus allows the one in pain and the care giver to get the timing right. Some philosophers and neuroscientists claim that evolutionary neurobehavioral solutions to timing problems such as these are implicated in the origin of empathy and ultimately consciousness itself (Churchland, 2002; Cole, 1998; Engen & Singer, 2012; van Rysewyk, 2011).

However, if pain is severe or chronic and the vagal brake is withdrawn (or dysfunctional), the concurrency of increased pain facial expression, cardiac output, and other mobilization behaviors (i.e., increased SNS and HPA output), means that, if care giving is to succeed in promoting healing and recovery, the care giver’s vagal brake must be dynamically reinstated. By applying their own vagal brake, care givers may regulate their own visceral distress and thereby succeed in allocating valuable metabolic resources to communicate safety to the one in pain (and themselves) through calming facial and head behaviors, eye gaze, and prosodic vocalizations (i.e., increasing the vagal brake decreases SNS and HPA output). Since the vagal brake of the person in pain has been provisionally withdrawn, the care giver is effectively an integrated external brain-heart-face mechanism (cf. Tantam, 2009, the ‘interbrain’).

Thus, the pain facial muscles function as neural timekeepers detecting and expressing features of safety and danger that cue the one in pain to quickly disengage from the source of wounding and pain, simultaneous with the rapid appearance or attenuation of pain facial activity, and also cue others who can help.

References

Chapman, C. R., Tuckett, R. P., & Song, C. W. (2008). Pain and stress in a systems perspective: reciprocal neural, endocrine, and immune interactions. Journal of Pain, 9(2), 122-145.

Churchland, P. S. (1989). Neurophilosophy: Toward a Unified Science of the Mind-Brain. Cambridge, Mass.: MIT Press.

Cole, J. (1998) About face. Cambridge, Mass.: The MIT Press.

Craig, K. D., & Patrick, C. J. (1985). Facial expression during induced pain. Journal of Personality and Social Psychology, 48(4), 1080-1091.

Craig, K. D., Prkachin, K. M., & Grunau, R. E. (2011). .The facial expression of pain. In D. C. Turk, & R. Melzack, Handbook of Pain Assessment, 2nd Edition (pp. 117-133). New York: The Guilford Press.

Engen, H. G., & Singer, T. (2012). Empathy circuits. Current Opinion in Neurobiology, 23, 1-8.

Hadjistavropoulos, T., Craig, K. D., Duck, S., Cano, A., Goubert, L., Jackson, P. L., Mogil, J. S., Rainville, P., Sullivan, M. J. L., de C. Williams, Amanda C., Vervoort, T., & Fitzgerald, T. D. (2011). A biopsychosocial formulation of pain communication. Psychological Bulletin, 137(6), 910-939.

Kok, B. E., & Fredrickson, B. L. (2010). Upward spirals of the heart: Autonomic flexibility, as indexed by vagal tone, reciprocally and prospectively predicts positive emotions and social connectedness. Biological Psychology, 85(3), 432-436.

Kunz, M., Lautenbacher, S., LeBlanc, N., & Rainville, P. (2011). Are both the sensory and the affective dimensions of pain encoded in the face? Pain, 153(2), 350-358.

Morecraft, R. J., Stilwell-Morecraft, K. S., & Rossing, W. R. (2004). The Motor Cortex and Facial Expression: New Insights From Neuroscience. The Neurologist, 10(5), 235-249.

Porges, S. W. (2001). The polyvagal theory: phylogenetic substrates of a social nervous system. International Journal of Psychophysiology, 42(2), 123-146.

Porges, S. W. (2006). Emotion: An Evolutionary By‐Product of the Neural Regulation of the Autonomic Nervous System. Annals of the New York Academy of Sciences, 807(1), 62-77.

Pu, J., Schmeichel, B. J., & Demaree, H. A. (2010). Cardiac vagal control predicts spontaneous regulation of negative emotional expression and subsequent cognitive performance. Biological Psychology, 84(3), 531-540.

van Rysewyk, S. (2011). Beyond faces: The relevance of Moebius Syndrome to emotion recognition and empathy. In: A. Freitas-Magalhães (Ed.), ‘Emotional Expression: The Brain and the Face’ (V. III, Second Series), University of Fernando Pessoa Press, Oporto: pp. 75-97.

Williams, A. C. D. C. (2002). Facial expression of pain: an evolutionary account. Behavioral and Brain Sciences, 25(4), 439-455.

#SciFund update: video complete!

My #SciFund video is finally complete!

Quite a mission to do (first time), but I am happy with the finished product.

Click on the image:

 

 

 

 

 

 

 

 

Here is a map showing the global distribution of participating scientists in Round 1 (2011) and Round 2 (May, 2012) of the #SciFund Challenge:

SciFunders Standing Tall and Talented

There is good news here

I cannot predict your every thought and action for the simple reason that most of my own thoughts and actions are completely spontaneous.

I cannot predict what I will do in most instances. I cannot know myself, so I cannot know you. True enough? We are both in the dark, it seems.

That sounds a bit bleak.

Is there any good news?

Yes: A person is not a vacuum. Human thought and action is shared. Shared, copied, modified, suppressed, distilled – we live in each other’s facial expressions.