Is pain where you feel it in the body, or in the brain? Neurophenomenology and the spatial aspect of nociception

Pain is interesting, salient, mysterious. It may feel like it is in one specific place in or on the body. It may feel diffuse, with gradations, or it may seem referred from one area to another. What is happening in the brain and in the body as these spatial aspects of pain are experienced? How much of the causation of pain occurs where we feel it, and how much occurs in the brain? Below is a series of probes and thinking aloud about where pain is, with speculations to stimulate my thinking and yours.  I’m not a “pain expert”, nor a bodyworker that heals clients, nor a physiologist with a specialization in nociception, but a cognitive scientist, with clinical psychology training, interested in body phenomenology and the brain.  Please do post this essay to Facebook, share it, critique, respond, and comment (and it would be helpful to know if your background is in philosophy, neuroscience, bodywork, psychology, medicine, a student wanting to enter one of these or another field, etc). Pain should be looked at from multiple angles, with theoretical problems emphasized alongside clinical praxis, and with reductionistic accounts from neurophysiology juxtaposed against descriptions of the embodied phenomenology and existential structures.  As I have mentioned elsewhere, it is still early in the history of neurophenomenology…let a thousand flowers bloom when looking at pain. We need data, observations, insights and theories from both the experience side as well as the brain side. Francisco Varela aptly described how phenomenology and cognitive neuroscience should relate:

“The key point here is that by emphasizing a codetermination of both accounts one can explore the bridges, challenges, insights, and contradications between them. Both domains of phenomena have equal status in demanding full attention and respect for their specificity.”

We all know what pain is phenomenologically, what it feels like, but how to define it? The International Association for the Study of Pain offers this definition: “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.” Of particular interest to neurophenomenology and embodied cognitive science is their claim that “activity induced in the nociceptors and nociceptive pathways by a noxious stimulus is not pain, which is always a psychological state.” Good that they do not try to reduce the experience of pain to the strictly physiological dimension, but I wonder how Merleau-Ponty, with his non-dualistic ontology of the flesh would have responded. Pain seems to transgress the border of mind and body categories, does it not? I am slowly biting off chucks of the work on pain at the Stanford Encyclopedia of Philosophy. Lots of provocative angles, including this one:

“there appear to be reasons both for thinking that pains (along with other similar bodily sensations) are physical objects or conditions that we perceive in body parts, and for thinking that they are not. This paradox is one of the main reasons why philosophers are especially interested in pain.”

Right now I am particularly interested in the spatial aspect of where pain seems to be, what I might label the spatial phenomenology of nociception. When I introspect on aching parts of my feet, it seems as if the pain occupies a volume of space. Using manual pressure I can find places on my feel that are not sore, right next to areas that are slightly sore, which are in turn near focal areas of highest pain. It seems as if the pain is locatable “down there” in my body, and yet what we know about the nociceptive neural networks suggests the phenomenology is produced by complex interactions between flesh, nearby peripheral nerves, the central nervous system, and neurodynamics in the latter especially. A way of probing this this would be to examine the idea that the pain experience is the experiential correlate of bodily harm, a sort of map relating sensations to a corresponding nerve activated by damage to tissue. So, is the place in my body where I feel pain just the same as where the damage or strain is? Or, Is pain caused by pain-receptive nerves registering what is happening around them, via hormonal and electrical signals? Or is pain actually the nerve itself being “trapped” or damaged, yet in a volume of undamaged tissue one can feel hurts? Could the seeming volume of experienced pain-space be a partial illusion, produced by cognizing the tissue damage as some place near or overlapping with yet not spatially identical to where the “actual” damage is, in other words a case of existential-physiological discrepancy? One scenario could be, roughly, that pain “is” or “is made of” nerves getting signals about damage to tissue; another would be that pain “is” the nerves themselves being damaged or sustaining stress or injury. Maybe pain involves both? Maybe some pain is one, or the other? In terms of remembering how my heel pain started, it’s not so easy, but I love to walk an hour or two a day, and have done so for many years. I recall more than ten years ago playing football in the park, wearing what must have been the wrong sort of shoes, and upon waking the next day, having pretty serious pain in my heel. Here are some graphics that, intuitively, seem to map on to the areas where I perceive the pain to be most focal:

from bestfootdoc.com

from setup.tristatehand.com

from plantar-fasciitis-elrofeet.com

If I palpate my heel, I become aware of a phenomenologically complex, rich blend of pleasure and pain. I crave the sensation of pressure there, but it can be an endurance test when it happens. Does the sensation of pressure that I want reflect some body knowledge, some intuitive sense of what intervention will help my body heal? How could this be verified or falsified? It is not easy to describe the raw qualia of pain, actually. I can describe it as achey and moderately distressing when I walk around, and sharp upon palpating. Direct and forceful pressure on the heel area will make me wince, catch my breath, want to gasp or make sounds of pain/pleasure, and in general puts me in a state of heightened activation. But I love it when I can get a therapist to squeeze on it, producing what I call “pain-pleasure”:

from indyheelpaincenter.com

This diagram below helps me map the sensations to the neuroanatomy. We need to do more of this sort of thing. This kind of representation seems to me a new area for clinical neurophenomenological research (indeed, clinical neurophenomenology in general needs much more work, searching for those terms just leads back to my site, but see the Case History section in Sean Gallagher’s How the Body Shapes the Mind).

from reconstructivefootcaredoc.com

What is producing the pain-qualia, the particular feeling? Without going too far into varying differential diagnosis, it is commonly attributed to plantar fasciitis.  There the pain would be due to nociceptive nerve fibers activated by damage to the tough, fibrous fascia that attach to the calcaneus (heel bone) being strained, or sustaining small ripped areas, and/or local nerves being compressed or trapped. A 2012 article in Lower Extremity Review states that “evidence suggests plantar fasciitis is a noninflammatory degenerative condition in the plantar fascia caused by repetitive microtears at the medial tubercle of the calcaneus.” There are quite a few opinions out there about the role of bony calcium buildups, strain from leg muscles, specific trapped nerves and so forth, and it would be interesting to find out how different aspects of reported pain qualia map on to these. Below you can see the sheetlike fascia fiber, the posterior tibial nerve, and it’s branches that enable local sensations:

from aafp.org

Next: fascia and the innervation of the heel, from below:

from mollyjudge.com

Another view of the heel and innervation:

from mollyjudge.com

Below is a representation of the fascia under the skin:

from drwolgin.com

There is a very graphic,under the skin, maybe not SFW surgeon’s-eye perspective on these structures available here. Heel pain turns out to be very common, and is evidently one of the most frequently reported medical issues. Searching online for heel pain mapping brings up a representation purportedly of 2666 patients describing where they feel heel pain: I can’t find where this comes from originally and can’t speak to the methodology, rigor, or quality of the study, but the supposed data are interesting, as is the implicit idea of spatial qualia mapping:  the correspondence of experienced pain to a volume of space in the body. It also quite well represents where the pain is that I feel. The focal area seems to be where the fascia fibers attach to the calcaneus, an area that bears alot of weight, does alot of work, and is prone to overuse. So, where is the pain? Is it in the heel or the brain? Is it in the tissue, the nerve, or both? Is there a volume of flesh that contains the pain? I am going to have to think about these more, and welcome your input. What about the central nervous system that processes nociceptive afferents coming from the body? A good model of pain neurophenomenology should involve a number of cortical and subcortical areas that comprise the nociceptive neural network: -primary somatosensory cortex (S1) and secondary somatosensory cortex (S2): -insula -anterior cingulate cortex (ACC) -prefrontal cortex (PFC) -thalamus Here are some representations of the pain pathways, or the nociceptive neural network:

from Moisset and Bouhassira (2007)

Moisett el (2009)

 

from Tracey and Mantyh (2012)

Broadly speaking, pain seems to be generated by tissue damage, inflammation, compromising the integrity of tissue, stress on localized regions, and so forth being processed by peripheral afferent pain pathways in the body, then phylogenetically ancient subcortical structures, and then the aforementioned cortical regions or nociceptive neural network.  As I have mentioned many times, making a robust account of how various regions of the brain communicate such that a person experiences qualia or sensory phenomenology will need to reference neurodynamics, which integrates ideas from the physics of self-organization, complexity, chaos and non-linear dynamics into biology.  It is gradually becoming apparent to many if not most workers in the cognitive neurosciences that there are a host of mechanisms regions of the brain use to send signals, and many of these are as time dependent as space dependent. Michael Cohen puts it thusly: “The way we as cognitive neuroscientists typically link dynamics of the brain to dynamics of behavior is by correlating increases or decreases of some measure of brain activity with the cognitive or emotional state we hope the subject is experiencing at the time. The primary dependent measure in the majority of these studies is whether the average amount of activity – measured through spiking, event-related-potential or -field component amplitude, blood flow response, light scatter, etc. – in a region of the brain goes up or down. In this approach, the aim is to reduce this complex and enigmatic neural information processing system to two dimensions: Space and activation (up/down). The implicit assumption is that cognitive processes can be localized to specific regions of the brain, can be measured by an increase in average activity levels, and in different experimental conditions, either operate or do not. It is naïve to think that these two dimensions are sufficient for characterizing neurocognitive function. The range and flexibility of cognitive, emotional, perceptual, and other mental processes is huge, and the scale of typical functional localization claims – on the order of several cubic centimeters – is large compared to the number of cells with unique physiological, neurochemical, morphological, and connectional properties contained in each MRI voxel. Further, there are no one-to-one mappings between cognitive processes and brain regions: Different cognitive processes can activate the same brain region, and activation of several brain regions can be associated with single cognitive processes. In the analogy of Plato’s cave, our current approach to understanding the biological foundations of cognition is like looking at shadows cast on a region of the wall of the cave without observing how they change dynamically over time.” But what of the original question? Is pain where you feel it in the body, or in the brain? It seems to me the answer must be both.  The experience of pain being localized there or a little on the left is a product of local tissue signals and receptor activation, which produces peripheral afferent nerve firing, which gets processed by spinal afferent neurodynamics, brainstem activation, thalamic gating, and then somatosensory, insular, anterior cingulated, and prefrontal cortical regions. Yet the real model of pain, one that invokes mechanisms and causes, remains elusive. And a good model of pain must account for the possibility of pain without suffering as well! For now, what I can offer are probes to get us speculating, thinking critically, and eventually building a clinical neurophenomenology of pain. If that interests you, by all means get involved.

What do clinicians come to know about their patient’s heart sensations?

What do clinicians come to know about their patient’s heart sensations? This is not a simple question, as it simultaneously looks at patients as people with bodily experiences, but also as humans understood as systems, as a sort of living machine. What is more intimate than our heart-beating, a familiar yet mysterious sensation we know to be at the very basis of our ongoing experience? Feeling a change in the rhythm or intensity of this fundamental aspect of our embodied existence can be very worrisome. Should clinicians believe patients who complain of cardiac rhythm changes? How accurate are people at detecting medically important heart-beat fluctuations? How should clinicians understand the relationship between symptoms as reported by the patient, and underlying physiological processes? These are complex and multifaceted issues, requiring nimble clinicians who integrate scientific knowledge as well as intuition about what the patient is experiencing bodily. Clinicans develop knowledge of their own bodies through life, and then are required to learn complex anatomical, physiological, and etiological concepts they will use to interpret their patient’s symptom reports. What patients have to say about what is happening in their bodies must be taken seriously, but not necessarily believed. The interrelated problems of how clinicians interpret patient verbal reports, reason about the relation between these reports compared to measurements and scientific models, and then make judgments about the patient’s accuracy in knowing about their own bodies are topics well worth honing in on, and to my knowledge, not throughly explored from a neurophenomenological perspective.

These acts of clinician cognition concerning their patient’s symptoms are framed by an evolving social and professional context. Modern medicine, like the Roman god Janus, stands two-faced, towards healing as an art, but also towards scientific models of disease. In the current era, what is known as “evidence-based medicine” requires an important shift in how clinicians operate, from historically rather unfettered individual judgments in some contexts, to increasingly accepting consensus-developed guidelines formulated from reviews of previous findings. Clinicans who have with great effort developed the ability to intuit diagnoses may have to defend their familiar constructs, criteria, heuristics, and practices if these are not bolstered by peer-reviewed studies, randomized clinical trials, systematic reviews, Bayesian statistical approaches to clinical problem solving, meta-analysis of previous data, and effectiveness metrics. Medical organizations can mandate “best practices” of patient care, “gold standards” of cost-effectiveness for ordering certain tests, references to efficacy criteria that must be satisfied before a program of treatment is established, and more. This ongoing process is transforming medicine, requiring that the traditional art of diagnosis based on years of education and experience be integrated with operationalized definitions, committee-approved metrics, and greater formalization, thus constraining individual opinion and practices in favor of organization-mandated standard operating procedures. Can symptoms based on an individual’s embodied experience be given proper attention in this brave new world of medicine?

I hope that more researchers would address the clinical aspects of neurophenomenology. This is a relatively new and undeveloped area. While William James and Erwin Straus were clinicians, as is Antonio Damasio, other pioneers such as Maurice Merleau-Ponty and Francisco Varela backgrounded medical concerns somewhat (however, if you are unaware of Varela’s haunting work at the end of his life “Intimate Distances -Fragments for a Phenomenology of Organ Transplantation“, it is a must-read.) Shawn Gallagher has made an excellent synthesis of philosophy and clinical studies in “How the Body Shapes the Mind“, a work that bears greater attention from the small community of neurophenomenology researchers.

For my part, I shall focus in on a particular area, palpitations, where changes towards operationalizing and standardizing the definition of “clinically significant” symptoms are occurring, with the aim of modeling the relationship between patient symptom reports and “significant” arrhythmias as revealed on ECG measurements. I will especially focus on how the predictive utility and accuracy of the reports can be operationalized, and attempt to represent for one domain how patients’ verbalization of their phenomenological state can be “mapped” onto measurements of cardiac rhythm abnormalities.

questions about information-processing theories of body-knowledge

Cognitive science explains mind and brain in terms of computation, information-processing, and representationalism: the ability of a cognitive system to change internal microstructure so as to correspond with important features of the internal or external world. One could do worse than to sum up the cognitivist model of the mind as “computations over representations”, in which features of the world or body are coded by the brain as symbols.

Whatever merits this “cognitivist” research program may have for models of syntactical production, the consolidation of short-term memories into long-term, the recognition of familiar faces, logical problem-solving, and other phenomena, I suspect that critical aspects of how people have knowledge of their bodies are not adequately accounted for by cognitivist approaches. I maintain that a careful analysis of the evidence reveals cognitive science has a flawed approach to modeling how well people know what is happening inside their bodies, and what mental and biological processes underlay this knowledge.

There are many aspects of psychological life that have never been the focus of cognitive science, and this absence is at it’s foundation the Cartesian rift at the heart of objective models that depict mind as machine. People experience a world of meaning framed by temporality and grounded in the lived body, but cognitive science focuses on a subpersonal realm of symbols, algorithms, information processing, representation, where mind is reduced to computation. To the extent that this approach yields results, it should be pursued, but cognition outstrips what cognitivism can model. There are aspects of cognition that are characterized by the existential questions, embodied experience, consciousness, meaning, and other phenomena, but it is precisely these that objectivistic, Cartesian cognitive science has not, for the most part, tried to explain. The difference is that of between worlds, like the gap between music grasped as experienced and meaningful, compared to music understood as a system that can be analyzed through abstract system-centered objectivistic modeling. It is true that science is typically understood in the latter terms, but neurophenomenology aims at a dialog between psychological life as experienced and cognition understood as a mechanism produced by te brain. There is not an immediate move toward reduction nor a premature assumption that embodied experience can be automatically modeled as a byproduct of systems.

In everyday life, and especially in conditions of sickness or disease, people notice aspects, qualities, and states of their bodies, and seek to get information about and from their bodies. Getting information about body-state can involve perception of a symptom, focused attention or introspection toward specific body regions or parts, remembering the way one’s body felt previously and comparing this to a current assessment, attempting to verbally express feelings about the way one’s body seems, paying close attention to a body part that is usually indistinct or in the background but suddenly is painful, and many other similar activities. Consider the following examples:

• a subject in a clinical trial of a medical device is asked whether or not they notice anything unusual or different about the way their body feels, and if so, to rate how much on a numeric scale;

• a person taking psychiatric medication for depression tells their psychiatrist about adverse side effects, such as a decline in libido, and an inability to grieve the loss of a loved one while at a funeral;

• someone who is drinking alcohol may calibrate their intake based on the memory of nausea from previous episodes of over-consumption;

• an obese woman is reported by American media to have been shocked upon finding she was in labor and on the verge of giving birth, having no previous knowledge of her pregnancy.

• a person who is being massaged, when asked to describe the sensation, reports a mixture of significant pleasure and mild pain when pressure is applied to very specific regions of their upper-back

In these and in similar cases, individuals involved are sensing, perceiving, remembering, and judging about their symptoms, body states, feelings, and sensations, and in some examples, reporting their experience to others. These are cognitive phenomena, but can ideas derived from symbolic logic and representationalist epistemology suffice to explain them? I would argue that there are a number of open questions about the utility of information-processing theories of body-knowledge.

Are the introspective reports, assessments, and statements generated by people about their body-state generally accurate, or not? What mechanisms account for the accuracy, or lack thereof?

To what extent do legacy concepts from cognitive science or information-processing models help or hinder the development of an understanding of how people access information and gain knowledge about their bodies?

How are we to understand the meaning(s) of the term “information” used to explain how and how well people know their own mental and physiological states? What is the relationship of “information” in the sense of physiological or biological systems to consciously reportable sensation, such that a person is getting information about their body state?

Are there many kinds of “information” involved in these models of internal state perception or “body cognition” found in clinical neurology, medicine, experimental psychology, and theoretical cognitive neuroscience? Or is there but one type of “information”, with different qualities or aspects that are described or measured in different ways?

Part II of Leder’s The Absent Body

“Spatiotemporal Continuity

The mysterious quality of our visceral space is based not only on such experiences but on all that is not experienced of our inner body, I have hitherto focused on what interoceptions we do have; they are marked by a limited qualitative range and a spatial ambiguity that together restrict our perceptual discriminations. Furthermore, as I will now address, there is a paucity of even such limited experiences.

Exteroception, at least during the waking state, manifests a certain spatiotemporal continuity. My eyes scan a visual world that is without sudden gaps or crevices. If I abandon one sense, perhaps closing my eyes, the other senses help to maintain the continuity of world. Similar­ly, proprioception traces out a completed sense of my surface body, allowing me to adjust every limb, every muscle, in appropriate motoric response to tasks. Though usually this sense is subliminal, I can close my eyes and proprioceptively hone in on the position, the level of tension or relaxation, in any region of the muscular body.

By way of contrast, the stream of interoceptive experience is marked by ineluctable discontinuities. In the above example, after eating the ap­ple it largely disappeared from perception only to resurface in an exper­ience of heartburn. This then faded away to silence, broken some time later by insistent cramps. This too passed. Finally, hours later I become aware of sensations from a new region signaling the need to defecate. But these are intermittent punctuations in a shroud of absence. Most of the intricate digestive process—its enzymatic secretions and peristaltic waves, its diffusions and active transports—proceeds without the pos­sibility of conscious apprehension. This is equally true of circulation, respiration, thermal or fluid regulation. By far the greatest part of my vegetative processes lies submerged in impenetrable silence.

Causal relations are rendered uncertain by these spatiotemporal lac­unae. I cannot be sure if my cramps are caused by an apple I previously ate, for this apple has, in the interim, disappeared from experience. Mo­ments of discomfort are noted while the baseline of ordinary functioning is largely invisible, it is as if my eyes only reacted to flashes of blind­ing light, the rest of the time residing in darkness.

This darkness is never absolute. When I focus inward at even the qui­eter times I still find some vestigial sense of my midsection enveloped in a sort of sensory neutrality, neither full nor empty, pleasured nor in pain. And this vague aura is not devoid of meaning. It shows that any hunger or illness has subsided. The very absence of discomfort is tinged by a positivity.

Moreover, through a heightened focusing of attention, I can increase my awareness of visceral processes. Certain dim sensations that I had never noticed—the feeling of my pulsing blood, the depths of respira­tion, the subtler reactions of my stomach to different foods—can be brought into experience by conscious effort. As cultural variations show, a certain degree of visceral disappearance can be attributed to Western insensitivities and overcome by a systematic development of powers. The awareness of and control over the inner body exhibited by trained yogis has far surpassed what used to be thought possible in the West.

Yet even such achievements take place only within an overall context of experiential disappearance. The very need for highly specialized training is evidence of the perceptual reticence of our viscera as com­pared to the body surface. And just as it is possible to speak of null points in relation to the surface body, the corporeal depths have their own phenomenological null points. That is, there are visceral regions that are almost entirely insensitive. In focusing upon stomach and gut I have ac­tually chosen two of the more loquacious organs. The kidney, gallblad­der. bone marrow, spleen, yield far less interoceptively. The par­enchyma of the liver, the alveolar tissue of the lung, are virtually with­out sensation. Unlike the completed perception of the proprioceptive body, our inner body is marked by regional gaps, organs that although crucial for sustaining life, cannot he somesthetically perceived.

We rarely thematize this sort of disappearance. Upon introspecting, I do not feel an emptiness in my body where my liver should be. This would make the absence into a presence-as-concealed hovering before my awareness. Rather, the absence of the liver parenchyma is so total that few would ever come to realize or remark upon it. Yet a medical mishap can suddenly awaken us to the significance of such bodily lac­unae. The vast gaps in our inner perception may conceal potentially damaging processes until they are far advanced. For example, while I may feel pain once damage to the liver has progressed to the point of affecting its membranous capsule, the initial process can go unper­ceived. Similarly, hypertension is experientially hidden through much of its career. As with my surface body, I can bring to bear upon these depth organs certain strategies of reflective observation. A blood sample can tell me a good deal about my liver function. Through a sphygmomanometer I can read off my blood pressure. I can look at an X ray of my lungs. I can even gaze through a colonoscope at the lumen and folds of my own colon. Such techniques enable me to gain knowledge concerning my viscera. Yet, as with my surface body, the absences that haunt my bodily depths are not effaced by these reflective maneuvers. Though I can visu­ally observe my colon, its processes still elude experience from within, The magical power my body has to absorb water and electrolytes is not perceived as I gaze through the endoscope upon this furrowed, tubular space. The mystery of my body is only heightened by the very strange­ness of the organ before me, its phenomenological noncoincidence with my body-as-lived.

Moreover, unlike the body surface, my inner organs tend to resist even these partial reflections. My viscera are ordinarily hidden away from the gaze by their location in the bodily depths, there is aspect of withdrawal may seem contingent, resulting from a sheerly physical harrier rather than an existential principle. Ye t this is to draw a false distinction; in the lived body, the physical and existential always intertwine.

The depth location of the viscera is no more contingent than the sur­face placement of the sensorimotor organs. Eye and hand could not perform their perceptual role unless they opened onto the external world- Thus, in order to perceive they must take their place among the perceptibles. They must be located at the body surface available to the gaze of myself and others, By way of contrast, my visceral organs, not constructed for ecstatic perception, disappear from the ranks of the per­ceived, I do not perceive from these organs; hence, they can hide beneath the body surface such that I do not perceive to them either. In fact, they require this seclusion just as the sensorimotor body requires exposure. My stomach, neither an organ of exteroception nor voluntary move­ment, could not screen the environment, secure appropriate foods, repel threats. It depends on a mediating surface, active and intelligent, to stand between it and the world, selecting what is needed for metabolic maintenance and protecting the vise us from hostile impacts. The hiddenness of vital organs, though frustrating at limes of disease, is essen­tial to healthy functioning.

Thus it is quite rare for the viscera to be exposed in life. This can happen, as in surgery, wartime injury, or violent accidents, yet these are pathological and dangerous occasions, Most commonly, the direct ex­posure of the inner organs implies or threatens the death of the person, Hence, as Foucault notes in The Birth of the Clinic, when nineteenth-century medicine made the direct perception of diseased organs an epistemological goal, the corpse, not the live patient, became the paradigmatic figure of truth. For the “anatomo-clinical” gaze, “that which hides and envelops, the curtain of night over truth, is, paradox­ically, life; and death, on the contrary, opens up to the light of day the black coffer of the body.”” While Foucault addresses this as a historical devel­opment, it manifests my phenomenological point; life itself is allied to a certain concealment, a withdrawal and protection of its vital center.

Body-knowledge: what is it?

I use the term“body-knowledge”  in my dissertation research primarily to refer to the experience of knowing about one’s own body, and especially embracing perception and assessments of the body through the body.  It is meant to straddle the classic cognitive psychology distinction between explicit knowledge that is verbalizable, and implicit knowledge that may only be revealed through experiments. Trying to define the term brings up a number of questions:

-How is “neurophysiological information-processing” related to “body- knowledge”?

-To what extent does the distinction between conscious and unconscious knowledge need to be invoked to explain that relationship?

-Should beliefs about the body be understood as part of body knowledge? What about attitudes, expectations, and desires concerning one’s body?

-Do the properties of the body vis-à-vis external objects and the external environment factor in, such as my knowledge of my ability to lift x kilograms of weights, or to effect changes in the world with my body?

-How is body-knowledge related to body-state information access?

This latter phrase can be thought of as “internal perception of information about the body”. For present purposes a heuristic understanding probably should suffice: body-state information access refers to what content an individual can perceive, sense, or detect about their body, but also to putative notions of information-processing in the afferent or other nerves that produce the content. As the term “cognition” signifies both mind as a collection of unconscious systems and (however problematically) mind as consciously experienced, body-state information access, as I use the phrase, straddles the divide between subjective and objective aspects of the body (compare to Merleau-Ponty’s (1968) notion of the “corporeal” or “the flesh”). One might extend the concept to mean that body-state information access also refers to a sort of “information gain” in bodily perception: for instance, being aware of digestive processes where one was not previously.

Interoception is another term needing examination: while classically interoception refers to perception of the visceral organs in the inside of the body, consider Bud Craig’s (2002) proposed redefinition (pg.655):

“Interoception should be redefined as the sense of the physiological condition of the whole body (including pain and temperature), and not just of the viscera”

Even if this broader sense becomes accepted, interoception will still include the sense of “interior perception”.  The more expansive signification should then overlap with somatic cognition, a term deployed by neuroscientists (Tanosaki, Suzuki, and Kimura, 2002) who use it to signify perception using body parts such as fingers, and also internal cognition, or even visceral cognition, labels used by researchers who model the relationship of the internal organs to the nervous system and perception (Adam, 1998, pg 156-159).

Compare these to body cognition, which might not only embrace the idea of knowledge of one’s lived, experienced body, “thinking with the body,” but also the somatic, visceral,  neurophysiological, and cognitive systems making the perception and knowledge possible. “Body cognition” would seem to have experiential or phenomenological (that is, felt) dimensions, but should also refer to what are commonly understood to be unconscious mental, neural, and other physiological processes enabling this knowing. The profusion of terms may reflect the inherent complexity of the systems involved, our partial and provisional understanding, or both. Analyzing how the notion of information relates to models that explain how unconscious neurophysiological processes give rise to conscious ones is a particular focus of my project.

As I will be use the term, body-knowledge embraces the notion of using the body as the means to perceive or assess itself, such as with symptom perception. The study of body cognition involves perspectives from many fields, but could be understood as a subset of embodied cognitive science, which differs from standard approaches to the extent that it emphasizes overcoming the Cartesian split between subject and object implicit in cognitive science, and the coupling of human mental activity to a meaningful world. One of the goals of a cognitive science of embodiment would be to construct a model of body knowledge good enough to explain how the embodied brain and mind make knowledge of the body, sensing or perceiving using the body, and the ability of people to use directed attention and introspection to gain “true information” or validated knowledge (compare to beliefs) about the body.

As I use the terms, body-knowledge and body-state information access refer to both experiential-phenomenological knowledge (“I feel hungry” or “I have an itch on my scalp, but not as bad as earlier”) that may form the basis of verbal reports as well as the unconscious, and presumably not explicitly stateable, underlying information processes comprising cognition. This distinction between stable and explicit and non-stateable or implicit knowledge is not a trivial one. Cognitive science, neuroscience, and psychophysiology propose that our conscious awareness and experience of information about the body to be to be somehow made of or caused by unconscious information, because cognitive processes are understood to be mostly unconscious.  Varela, Thompson, and Rosch (1991, pg. 49) point out that cognitive science:

“…postulates processes that are mental but that cannot be brought into consciousness at all. Thus we are not simply unaware of the rules that govern the generation of mental images or of the rules that govern visual processing; we could not be aware of these rules. Indeed, it is typically noted that if such cognitive processes could be made conscious, then they could not be fast and automatic and so could not function properly”

A critical look at the information-processing theories used to explain body-knowledge

The psychologist Raymond Gibbs (2006) in Embodiment and Cognitive Science asks (pg. 28) “What underlies people’s abilities to move as they do and have any awareness of their bodies?”

The conventional answer given by psychology, medicine, and cognitive neuroscience is physiological and cognitive systems using information-processing. Gibbs cites the work of Bermudez, Marcel, and Eilan (1995) who list a series of multiple internal physiological information sources that enable motor activity and somatic perception (pg. 13):

“(a) Information about pressure, temperature, and friction from receptors on the skin and beneath the surface.

(b) Information about the relative state of body signals from receptors in the joints, some sensitive to static position, some to dynamic information.

(c) Information about balance and posture from the vestibular system in the inner ear and the head/trunk dispositional system and information from pressure on any parts of the body that might be in contact with gravity-resisting surfaces.

(d) Information from skin stretch and bodily disposition and volume.

(e) Information from receptors in the internal organs about nutritional and other states relevant to homeostasis and well-being.

(f) Information about effort and muscular fatigue from muscles.

(g) Information about general fatigue from cerebral systems sensitive to blood composition”

These formulations follow the contemporary scientific trend of explaining systems, processes, entities, and relationships in terms of computation and information (and, often enough, representation).  It is relatively rare in such contexts to encounter authors worrying overmuch about the meaning of the term “information” though there are attempts to effectively operationally define it via metrics, i.e. to quantify the information content of a system via Shannon-style or other measurements (Gardner, 1985). Perhaps “information” is indispensable as a term of convenience, but a critical reader should ask what the term means in context, when the term is used as a heuristic, what value the term adds, whether ambiguity is lessened or increased, and whether it would be better to emphasize the provisionality of information concepts.

Probably it would be better to refer to “information” much of the time, but this becomes stylistically cumbersome very quickly.

In any event, current theories of psychophysiological processing, clinical studies of symptom-perception accuracy, cognitive models using mechanisms explaining explicit, verbally-stateable knowledge, and other theories conceptualize our knowledge of our bodies in terms of information-processing, though the connection between “knowledge” and “information” is often not explicit.

How are we to understand the meaning(s) of the term “information” used to explain how and how well people know their own mental and physiological states? What is the relationship of “information” in the sense of physiological or biological systems to consciously reportable sensation, such that a person is getting information about their body state? Are there many kinds of “information” involved in these models of internal state perception or “body cognition” found in clinical neurology, medicine, experimental psychology, and theoretical cognitive neuroscience? Or is there but one type of “information”, with different qualities or aspects that are described or measured in different ways? What metrics or formalisms are most appropriate for each type?

Information-processing, computational, cognitivist, and representational formulations may privilege objective “system-centric” meaning of information, performing an implicit reduction of information in an experiential/phenomenological sense, without calling attention to the reduction. It may be useful, or even true, that quantities can be mapped on to qualities, following the accepted principle in philosophy of science that the ontology (known elements, entities, processes, features, properties and their relations) from one domain can be reduced to that of another domain, with properties from the one domain or level of scientific description to more fundamental explanatory ones in another domain (Churchland, 1989). In this view, the mechanistic and reductionistic work that the ontology of genes and DNA (and possibly information-processing theory) does in explaining cell biology will hold for the relationship between brain and cognition. Indeed, a standard view in psychology and neuroscience (and to an extent philosophy of mind) holds that concepts from cognitive neuroscience, computer science, and information-processing theory can mechanistically explain particular aspects of bodily awareness, and at some point law like or nomological generalizations will become apparent, effectively performing a reduction.

I maintain that we should be careful in using an overdetermined term such as “information” to prematurely unite concepts from different domains. Traditionally, the philosophy of science has had a role in calling attention to instances where the use of concepts from one domain are used to explain another without careful explication of the move that is made (what one might call “stealing a base”), but unfortunately, the specialized nomenclature of philosophy leaves some scientists and clinicians alienated from such discourse.

Stretch your imagination, take the long view, remember Thomas Kuhn: do you think people in 100 years will be explaining body-knowledge as an information-processing system?

Modularism vs. globalism in cognitive neuroscience: implications for a science of body-knowledge

Models of how people are able to access physiological state information should take into account a long-running divide in cognitive neuroscience about to what extent explanations, models, and purported mechanisms privilege local, reductionistic, and/or modular theories, as opposed to global and holistic theories that emphasize connectedness with and interdependence of particular systems to the entire brain. The debate is described by the dynamicist Walter Freeman (Freeman and Holmes, 2005) :

“In one view, cortex is a collection of modules like a piano keyboard, each with its structure, signal, and contribution to behavior. In the other view, the neocortex is a continuous sheet of neuropil in each cerebral hemisphere, which embeds specialized architectures that were induced by axon tips arriving from extracortical sources during embryological development. Localizationists analogize the neocortex to a cocktail party with standing speakers; each module gives a signal that, when activated like a voice in a room, by volume conduction occupies the whole head and overlaps other signals… Globalists analogize neocortex to a planetary surface, the storms of which are generated by intrinsic dynamics and modified by the structural features of the surface”

The issue of “module activation” vs. “global pattern dynamics” should be kept in mind while reviewing the evidence for specific regions as crucial to biological models of sensation or perception. Nonetheless, for researchers investigating the neurophysiological basis of access to interoceptive information or body-knowledge focus on a number of cortical areas of interest, particularly somatosensory cortex, orbitofrontal cortex, insular cortex, and cingular cortex/cingulate gyrus. The somatosensory cortex or (S1) is conceived as containing “maps” of body surface areas. A standard interpretation would explain the perception of touch, temperature, and pain as occurring through sensory nerves, which are joined into the spinal cord, and which eventually route through the thalamus, and then the cortical region known as the postcentral gyrus.

One standard refinement to the traditional model gives the label “primary somatosensory cortex” only to the area shown in red, Brodmann area 3 (Kaas, 1983). In any event, primary somatosensory cortex/S1 is conventionally modeled as having four complete maps of the body surface. Arguably, the biological/anatomical grounding of this concept allows one to state that the somatosensory cortex/SI contains “multiple representations of the sensory surface of the body,” without running the risk of invoking representationalist epistemologies, with their polymorphous and “mentalistic” significations. Over time, a picture has emerged of sensation occurring on the outer surface of the body, and then activating S1: neurons in these regions are firing (generating electrical discharges and secreting “signaling” molecules across synapses) at a higher amplitude. Any model that accounts for how perception and awareness of the body is possible will likely need to reference the role of somatosensory cortex.

Another cortical region implicated in interoception or internal perception is that part of the frontal lobes known as the orbitofrontal cortex, which can be defined as that part of the prefrontal cortex that receives certain key afferent projections from the thalamus (the so-called “gateway to the cortex), which receives afferent projections from the body, including the visceral organs. In theory, enhanced activation of physiological state (such as heart rate increase) should be reflected in increased activation of orbitofrontal cortices.

Studies of the role of cortex in processing internal body state often emphasize the role of the (formerly) obscure structure known as the insula, a cortical structure which is nonetheless tucked away underneath the visible cortical layers. The anterior portion of the insula is especially implicated in interoception and internal body-state “information gain”.

Yet another specialized brain area becomes more active in those psychophysiological processes involving internal body state dynamics: a collection of white-matter fibers known as the cingulate gyrus of the cortex.

Again, it should be stressed that neuroscientists may debate the extent to which any one region’s activity should be privileged against global overall processes. Certainly, S1, orbitofrontal cortices, anterior insula and anterior cingulate gyrus are only one of a series of regions that play a part in allowing visceral perception, interoception, or a gain in information about the inside of the body. Emphasizing the contribution of such discreet areas carries forward the “modularist” tradition, while other models will stress more of a global or holistic system of interactions, which is a classic debate in psychology and neurology (Gardner, 1985). Arguably, the pre-understanding of how much processing is done by local “modules” as opposed to collective and global activities influences the very means of data collection (Freeman and Holmes, 2005).

Gallagher and Coles on body schema vs. body image and the body percept

The philosopher Shaun Gallagher has collaborated with neurologist Jonathan Coles on the significance of patients with enigmatic body-knowledge problems (Gallagher and Coles, 1998).  Gallagher has analyzed this clinical data in the light of phenomenology and neuroscience, and has  an essential book  for anyone interested in neurophenomenology: How the Body Shapes the Mind

Gallagher is formulating a sophisticated take on embodied cognition that redresses the relative lack of attention by Varela and others to clinical studies of body knowledge disorders .  I have believed for some years that the wealth of neurological case studies  presenting puzzling data needs more focus in neurophenomenology. Since the early 20^th century, numerous patients with body knowledge based disorders and pathologies have come to light, leading to the notion of a body schema (Head and Holmes, 1911), which Gallagher and Coles (p.372) say involves:

“…a system of motor capacities, abilities, and habits that enable movement and the maintenance of posture. The body schema is not a perception, a belief, or an attitude. Rather, it is a system of motor and postural functions that operate below the level of self-referential intentionality, although such functions can enter into and support intentional activity. The preconscious, subpersonal processes carried out by the body- schema system are tacitly keyed into the environment and play a dynamic role in governing posture and movement. Although the body-schema system can have specific effects on cognitive experience…it does not have the status of a conscious representation or belief”

Gallagher and Coles maintain that progress in understanding embodied cognition requires a distinction between this body schema and the notion of the body image (p.371):

“The body image consists of a complex set of intentional states-perceptions, mental representations, beliefs, and attitudes–in which the intentional object of such states is one’s own body. Thus the body image involves a reflective intentionality. Three modalities of this reflective intentionality are often distinguished in studies involving body image:

(a) the subject’s perceptual experience of his/her own body;

(b) the subject’s conceptual understanding (including mythical, cultural, and/or scientific knowledge) of the body in general; and

(c) the subject’s emotional attitude toward his/her own body”

Gallagher emphasizes the wide variety of ambiguous and contradictory ways these terms have been used, and while noting some critics have proposed that deploying new terms could eliminate such confusion, he labors to develop a dependable, standard use of the technical terminology that can serve to make sense of clinical neurophenomenology such as that of the patient I.W, who suffered damage to nerves below the neck. This man now has to consciously will in order to perform actions people normally take for granted (p. 374):

“Maintaining posture is, for him, an activity rather than an automatic process. His movement requires constant visual and mental concentration. In darkness he is unable to control movement; when he walks he cannot daydream, but must concentrate constantly on his movement. When he writes he has to concentrate on holding the pen and on his body posture. IW learned through trial and error the amount of force needed to pick up and hold an egg without breaking it. If his attention is directed toward a different task while holding an egg, his hand crushes the egg”

The usefulness of the crisp distinction between body schema and body image becomes apparent when trying to explain the patient’s body experience and body knowledge (though Gallagher states that there is not in fact such a simple distinction possible in many cases). Normal people can perform such acts without much explicit attention, which is to say such common actions are enabled by the subconscious processes characterizing the body schema. I.W, on the other hand, must carefully and consciously go through the necessary steps to perform everyday acts. Adopting Gallagher’s distinction, we could say in the absence of the unconscious body schema, the patient must now depend on his conscious body image. To the extent this distinction is true; it should help a great deal in unpacking the various meanings of body-knowledge.