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

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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.

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How to operationalize the “body-knowledge” construct so it can be analyzed and measured

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I started using the term “body-knowledge” a few years back as a way to label the extent to which people can accurately report symptoms or interior sensations. It is not as of 2010 a popular term. The earliest citation of the term I know of is from a clinical neurology paper by Sirigu, Grafman, Bressler, and Sunderland, (1991): Multiple representations contribute to body knowledge processing: Evidence from a case of autotopagnosia

“Body knowledge” does quite not have the same meaning as “embodied cognition”, “body image”,”body schema”, “interoception”, “visceral perception”, or even “body cognition”, though there is considerable overlap. I typically use the concept body-knowledge to emphasize the verbal reporting of internal states. My epistemology teacher years ago taught me a great idea:

To know something, you have to know that you know it, and to know that you know it, you have to be able to say it.

I wouldn’t defend that as the end-all be-all theory of knowledge, but it works as a heuristic at the least. For now, I use “body-knowledge” to refer to how well people can know and verbally report on what is happening to their physiological states.

To analytically probe this construct, I started looking very deeply at a particular domain: symptom reporting about cardiovascular processes. I have found some useful results from earlier studies that serve as a guide to help approximate how accurate people are when they feel and report palpitations: their heart is racing, they feel irregular beats, heart thumping or pounding, skipped beats, and so forth. Evidently a fair amount of the time people suffering from panic disorder or anxiety “cognize” otherwise benign sensations and report heart problems, and such false positives adds a great deal of expense to the healthcare system.

Symptom report accuracy is a largely unexplored area for the young field of neurophenomenology: how much of what is happening inside our bodies is accessible to our minds? Very little of the existing neurophenomenology literature deals with these issues.

How can the “body-knowledge accuracy” construct be operationalized, analyzed and measured? For the particular domain of palpitations reporting, here are some useful core metrics:

From ‘The Validity of Bodily Symptoms in Medical Outpatients,” (Barsky, 2000) Chapter 19 in The Science of Self Report (Stone, A, ed): -When patients complaining of palpitations undergo 24-hour, ambulatory, electrocardiographic monitoring, 39% to 85% manifest some rhythm disturbance; the vast majority of these arrhythmias are benign, clinically insignificant, and do not merit treatment). Although as many as 75% of these patients with arrhythmias report their presenting symptom during monitoring; in only about 15% of cases do these symptom reports coincide with their arrhythmias.

From Barsky, Ahern, Delamater, Clancy & Bailey (1997): -145 consecutive outpatients referred to an ambulatory electrocardiography (Holter) laboratory for evaluation of palpitations were accrued, along with a comparison sample of 70 nonpatient volunteers who had no cardiac symptoms and no history of cardiac disease. A symptom was considered accurate when it followed within 30 seconds after any demonstrated arrhythmia.

-average positive predictive value (PPV)… is equal to the number of reported symptoms that were preceded by an arrhythmia divided by the total number of symptoms reported (true positives / [true positives + false positives]).

-Ninety-nine palpitation patients (68%) reported at least one palpitation during monitoring. Among those patients who were symptomatic, the mean number of diary symptoms reported in 24 hours was 3.7. The mean PPV for all symptom reports among palpitation patients was 0.399, compared with a mean PPV = .118 for the nonpatient volunteer sample (p = .01).

-the palpitation descriptors most likely to be accompanied by electrocardiographic abnormalities are heart stopping, fluttering, and irregular heartbeat. The least predictive descriptive terms used by the patients were racing and pounding.

-34% of the symptomatic palpitation patients and 11% of the asymptomatic comparison subjects were classified as accurate reporters

experimental physiology, interoception, and body knowledge

interoception, Uncategorized, visceral perception

The work of experimental physiology researchers, such as Gyorgy Adam (1998) and Oliver Cameron (2002), as well as the psychologist James Pennebaker (1982) have opened up our understanding of how our cognition, brain, and peripheral nervous system allow us to know about our internal states. Such research probes the ability of people to sense and perceive processes and events interoceptively or visceroceptively-sensation via the visceral organs, typically the gastrointestinal tract or cardiovascular system. In a series of experiments lasting decades, described in Visceral Perception: Understanding Internal Cognition, Adam and colleagues (1998) painstakingly measured the ability of human subjects to perceive visceral changes. While much of their work is of primary interest to physiologists, for the present purposes it suffices to emphasize these claims and implications:

• The classical conception of the viscera, emphasizing their autonomic (maintaining homeostasis) activity, has not generally taken into account that sensory nerves innervate these organs.

• There are “dim and murky” but experimentally verifiable unconscious and conscious perceptions of these organs’ states.

• Conscious perception of visceral or interoceptive changes will tend to be “contaminated” with skin/surface based “somatic” perception, making “pure” visceral perception very difficult to verify.

• While cognitive neuroscience has fixated on the central nervous system, humans unconsciously and experientially are affected by various peripheral nervous system activities in the insides of their bodies, appropriately titled internal cognition (Adam, 1998).

Adam stresses the provisional, rather than the definitive, state of scientific knowledge of such concepts. Cameron (2002), in Visceral Sensory Neuroscience: Interoception, builds on Adam’s and other research, and attempts to contextualize what is known about internal body perceptions, skin and touch sensations, muscular control of movement, and other sensations. He addresses fundamental questions about how to taxonomize body knowledge, and writes that (pp. 274-275):
Rather than considering interoceptive processes, perhaps defining an overall bodily sense (or more than one-bodily senses) might be more appropriate…Would it not be more appropriate to define (as has been done by others) a bodily sense, including interoception, proprioception, labyrinthine function (i.e., the experience of the body in space), and other afferent information from the body?

The tentative appraisal of Adam and Cameron can only convey a sense of the complex nature of the phenomena at hand. Body knowledge, symptom perception, interoception, visceroception, and internal cognition are overlapping terms which need to be disambiguated. Yet this task is made all the more difficult because of the complexity of the problem of assessing how accurate people are at knowing their internal states.

Models of body knowledge are informed by practical medical and clinical needs. Physicians and clinicians routinely ask patients to report on their bodily sensations, while cognitive scientists, neuroscientists, and experimental psychologists often request subjects to verbally report on their perceptions. How true or “veridical” verbal reports are about objectively-measurable phenomena such as heart rate or blood pressure is a subject of debate. An extensive review by Pennebaker (1982) in The Psychology of Physical Symptoms of numerous results of studies measuring the abilities of normal humans to accurately report on physiological state found some limited evidence for accurate monitoring and reporting, but the bulk of data suggested people are poor at such tasks.

While this view may indeed represent something of a consensus, other authors (Fisher, 1966); (Adam, 1998) emphasize instances of relatively accurate capacity for interoception or perception of internal organ state, accuracy of perception of changes in external stimuli such as light or sound intensity (Stevens, 1975), practical necessity in clinical and medical contexts of asking patients to introspect and report on body state (Heilman and Valenstein, 2006) or numerous other perspectives that variously substantiate the accuracy and/or utility of verbal reports of sensation and perception. New data should be generated to shed light on two important (and overlapping) issues:
-the relative accuracy of verbal reports, which can be provisionally understood as representative fidelity to access to physiological state information.

-the neurobiological mechanism(s) by which people monitor and “get information” about their internal states.

The first issue above typically requires comparison of subject evaluations compared to objective measurements, while the latter usually involves imaging technology, such as EEG, fMRI, and other technologies. A model adequate to explain the results of both data sets will require bridging concepts that serve to link cognitive and biological levels of description. It should not be assumed at the outset whether or not information-processing models are up to that task. It may be that concepts from outside information-processing theory will be required to explain the data.

Neurodynamicist Walter Freeman on globalist vs. modularist approaches to EEG

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Walter Freeman (http://sulcus.berkeley.edu/) is very prominent within the neurodynamics  world, but is perhaps not as well known to the neurophenomenology and emobodied cognition communities as he should be. This is possibly because of the forebodingly technical nature of the physics concepts he employs. He told me at a conference some years ago that his views were very close to those of Francisco Varela, who himself was a dynamical systems neuroscientist. He is quite possibly the world’s foremost expert modeling cognitive neurodynamics with EEG. I am examining his work again as I am in the process of designing an EEG study.  Our Science Club in Austin has been wrestling with his paper “Metastability, Instability, and State Tranistions in Neocortex” (Freeman and Holmes, 2005) where he presents a “globalist” alternative to researchers who focus on “modules lighting up:”

“Humans observe and grasp complex events and situations by means of expectations that have the form of theories. A theory determines the techniques of observation, which in turn shape what is observed and
understood. The classic case in physics is the wave–particle duality, in which the choice of one or two slits determines the outcome of the observation. A similar situation holds for the classic debates among proponents of competing theories about neocortical dynamics: localization vs. mass action. 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. Cooperative domains of varying size emerge within each hemisphere during behavior that includes the specialized.

Observers of both kinds use electroencephalograms (EEGs) and units to test their models. Localizationists (e.g. Calvin, 1996; Houk, 2001; Llina´s & Ribary, 1993; Makeig et al., 2002; Singer & Gray, 1995) 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. On the assumption of stationarity, the signals can be separated by independent components analysis (ICA) of multichannel EEG recordings. Globalists (e.g. Amit, 1989; Basar, 1998; Freeman, 2000) analogize neocortex to a planetary surface, the storms of which are generated by intrinsic dynamics and modified by the structural features of the surface.

These analogies throw into sharp relief the contrasting assumptions and inferences on which the two theories are based. Further, they justify the different methods by which the EEGs are processed, so that after the processing the two forms of the postprocessed EEG data differ dramatically, each legitimately in support of the parent theory. This is
why any description of a brain theory should be prefaced by a review of the methods used to get the data that supports the theory

Raw EEG data must be preprocessed prior to measurement. Here six decisions are summarized that have to be made by localizationists and globalists before they acquire EEG data. The choices are diametrically opposed (Freeman, Burke, & Holmes, 2003; Freeman & Holmes, 2005).

(i) According to localizationists, specified behaviors require activation of selected cortical modules that give signals at specific stages of the behaviors and are otherwise silent. The background EEG is incompatible
with this expectation, so they adopt the theory established years ago by Bullock (1969) and Elul (1972) that background EEG is dendritic noise, which is so smoothed by volume conduction, particularly at the scalp, that it has no identifiable spatiotemporal structure. They use time ensemble averaging (TEA) to attenuate the noise in proportion to the square root of the number of repeated stimuli that activate the modules, and to extract the expected signals as event related
potentials (ERPs). Globalists view the background
activity as the necessary pre-condition for execution of the specified behavior. That activity is modified by conditioned stimuli in differing ways in various areas of neocortex. The induced modifications are not time-locked to triggering stimuli, so that TEA cannot be used. Instead, spatial ensemble averaging (SEA) is used to extract reference values for sets of
phase and amplitude values from multiple EEGs.

(ii) The sensor of choice for localization is the depth microelectrode, because the size of the tip determines the acuity of spatial resolution. For globalization the spatial resolution is determined by the interelectrode
distances, so the electrode face to minimize noise should be as large as possible without touching neighbor electrodes.

(iii) Both observers use as many electrodes as possible. Localizationists space their electrodes as far apart as possible to sample from as many modules as they can. Globalists space them closely to avoid spatial aliasing and undersampling of spatial patterns of cortical activity.

(iv) Localizationists sharpen the spatial focus of the signals by high-pass spatial filters such as the Laplacian to correct the smoothing by volume
conduction. Globalists use low-pass spatial filters to attenuate contributions that are unique to individual electrodes and enhance the sampling of synchronized field potential activity.

(v) Narrow band-pass filters are favored by localizationists on the premise that modular signals are likely to be bursts at definite frequencies such as 40 Hz. Globalists prefer broad-band filters in expectation that oscillatory signals in EEGs are aperiodic (chaotic).

(vi) Signal sources are localized to modules by fitting equivalent dipoles to the filtered data in order to solve the inverse problem. Global signals are not confined to specific anatomical sites; they are localized not in
the Euclidean space of the forebrain but in multidimensional N-space, where N is the number of available electrodes. These diametrically opposed choices in data processing lead to widely divergent EEG data, and the data lead to theories that are skew. The two theoretical positions are more complementary than conflicting”

History of the development of neurophenomenology pt.3: the modern era

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(Part I is here, and part II is here)

There  are a small number of researchers in neuroscience, cognitive science, and philosophy, that have developed a body of work that is properly called neurophenomenology. The most recognizable and productive was the Chilean biologist and cognitive neuroscientist Francisco Varela (1946-2001), who is likely better known for co-developing the theory of autopoesis.  He was possibly the first neuroscience researcher since Erwin Straus to have found the very technical phenomenological methods developed by Husserl to be a valuable resource. Varela adopted as much of the Husserlian methdology as he saw fit, so as to make progress on the notoriously difficult problems  inherent to relating cognitive neuroscience data with first-person verbal reports. Varela’s  essay”The Specious Present: A Neurophenomenology of Time Consciousness” was in particular influenced by Husserlian methodology.

Collaborating with eminent categorization researcher Eleanor Rosch and the philosopher Evan Thompson, Varela in 1991 published The Embodied Mind: Cognitive Science and Human Experience. In my opinion this was the most important book on cognitive neuroscience of the 1990’s (Daniel Dennett would not agree, but has an interesting critique here where he refers to it as “a major contribution to our understanding of cognitive science”.) I believe The Embodied Mind effectively provides a foundation for neurophenomenology, and is the most important work in the field (though the term  did not appear in the volume).

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As far as I have been able to determine, the term neurophenomenology first appears in 1988 with anthropologist and “biogenetic structuralist” Charles Laughlin’s “The Prefrontosensorial Polarity Principle: Toward a Neurophenomenology of Intentionality“, in Biology Forum 81 (2): 243-260 (I cannot find the original article, but there are references to it). Likely many encountered the term in 1990’s  Brain, Symbol & Experience: Toward a neurophenomenology of human consciousness by Charles Laughlin, social psychologist John McManus, and psychiatrist Eugene d’Aquili.

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This is a fascinating book of great ambition: to  model language and cultural systems of meaning through a non-reductive cognitive neuroscience. The section on existential-physiological discrepancy is worth the price of admission alone!  Laughlin was kind enough to give me his perspective on this fertile period: evidently Varela likely encountered the term through this book.  I for one was thrilled in1996 when Varela published “Neurophenomenology: A methodological remedy to the hard problem” in the Journal of Consciousness Studies.

Francisco Varela: biologist and neurophenomenologist

Varela made a presentation to the “Towards a Science of Consciousness” conference in Tucson in April 1996. Here he delivered an address later published as “A science of consciousness as if experience mattered”. In it he defines the field:

“The Working Hypothesis of Neurophenomenology

Only a balanced and disciplined account of both the external and experiential side of an issue can make us move closer to bridging the biological mind-experiential mind gap:

Phenomenological accounts of the structure of experience and their counterparts in cognitive science relate to each through reciprocal constraints.

<snip>

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. It is quite easy to see how scientific accounts illuminate mental experience, but the reciprocal direction, from experience towards science, is what is typically ignored.

The study of experience is not a convenient stop on our way to a real explanation, but an active participant in its own right.”

At the time of this presentation, “consciousness studies” was enjoying something of a rennaissance, and while only a small pool of researchers were explicitly refering to neurophenomenology as such, notions of “embodied cognitive science”, “situated cognition”, “hot” (as in emotional) cognition, and “affective neuroscience” were circulating among much broader group.  At one time for a neuroscientist or even psychologist to admit they were researching consciousness would supposedly invite at least skepticism, but in the 1994  the famously hard-nosed reductionist and DNA researcher Francis Crick (1916-2004) worked on and advocated a neuroscientific approach to consciousness:

The_Astonishing_Hypothesis(Cover)

By advocating a cognitive neuroscience of consciousness, Crick helped to legitimize a field that had been controversial. and many computer scientists, neuroscientists, philosophers, biologists, psychologists, and even physicists became involved in a roiling, highly publicized series of debates and conferences on mind, brain, and consciousness.

One reads there  had been something of a stigma placed upon brain scientists who dared to try to model consciousness or “subjectivity”; now leading neuroscientists like Gerald Edelman and Antonio Damasio write best-sellers about consciousness and emotions. Damasio in particular is arguably the leading expositor of the view that embodied  emotions are a critical part of cognition, a perspective that has been long maintained by the phenomenological psychologists. He has developed the somatic marker hypothesis, which states that decision-making is affected by emotions,due to visceral signals coming from the body.

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Damasio, perhaps the leading researcher in the world on consciousness, draws on the work of Varela, who died at a relatively young age in 2001. Without  this charismatic neuroscientist leading the effort, it is unclear what is next for neurophenomenology.  One possible, and serious, bifurcation point is present: the influential reductionist and cognitivist philosopher Daniel Dennett has made an important distinction between “upper case'” Husserlian Phenomenology andlower case” phenomenology, the far-less controversial latter endeavor being (in his formulation) amenable to cognitive neuroscience.

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Consciousness Explained is endlessly stimulating, eminently readable, funny, provocative, and most importantly provides a pragmatic account of how to move the cognitive science of consciousness forward methodologically via heterophenomenology This method may prove fruitful for neurophenomenology, but Consciousness Explained ultimately devotes it’s hundreds of fascinating pages to a defense of vanilla reductionistic computational/representational cognitivism.

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Dennett: author of the pathbreaking 1991 volume Consciousness Explained

Consciousness Explained proposes that verbal reports generated by the introspection of a subject can be treated as data through the adoption of a “heterophenomenological” method, where no assumptions about the reality-status of the introspection or description are made (a .pdf from The Journal of Phenomenology and Cognitive Science outlining  a rather plausible  defense of the heterophenomenological method is here) The upshot is that cognitive neuroscience and psychology (now, at least) have no need of  trained “autophenomenologists” such as  Edmund Husserl or William James. It is enough to simply get regular untrained subjects to verbally report on what they believe they are experiencing or percieving or remembering, and these reports are nothing more than data about subjects’ beliefs about their mental states. Heterophenomenology is thus a sort of behaviorist-friendly phenomenology.

Heterophenomenology attempts to get around the problem of subjectivity: the reports are simply treated as data about the subject’s beliefs or “intentional stance”, which can then be used to correlate with neuroimaging or otherwise inform model-building in the cognitive neurosciences. But Dennett maintains that there can be no “first-person” science, where descriptions of experience from the researcher are fundamental, which is what Husserl, William James, and Varela espoused (read Dennett’s  crisp missive on the subject of “The Fantasy of First-Person Science” at http://ase.tufts.edu/cogstud/papers/chalmersdeb3dft.htm).

This distinction then opens up two broad possible paths for neurophenomenology: using a strictly “hetero” and third-personal methodology, or building on tradition of the “auto” and first-personal way (it should be made clear that this distinction is not only germane to neurophenomenology, but also to the broader field of consciousness studies and possibly cognitive neuroscience, psychology, and medicine).  However, both may be useful, depending on context and the particular research problem of interest.  The “hetero” method is more-or-less what psychologists and behavioral researchers have done for a century (the twist being how the data is to be regarded: not about reality so much as subjects’ beliefs about reality).

Varela was emphatic that phenomenology, done properly, is not introspection at all. Following Husserl, he asserted that what a disciplined, trained observer can observe and report about consciousness is vastly different than what a “civilian” can do.  The  neurophenomenological theory of Varela does not accept Dennett’s formulation that what he (Dennett) calls the “auto” tradition is not science. Rather, “mutual constraints” define how mind science uses the careful descriptions of trained observers or phenomenolgists relative to “objective” behavioral or cognitive neuroscience data.  If such training can yield reports with accurate characterizations of the structure of phenomenal awareness, or even the underlying underlying cognitive processes, autophenomenology will be valdiated.

Before his passing in 2001, Varela produced many writings on these methodological issues, as well as other topics on the neurophenomenology, which are now circulating in book form: The View from Within (with Jonathan Shear) and the multi-authored Naturalizing Phenomenology: Issues in Contemporary Phenomenology and Cognitive Science.

Time will tell if Varela’s or Dennett’s visions of a science of consciousness prevail. While it is possible there will be a reaction against so much time and effort being devoted to these matters (as in the behaviorist disavowal of introspection used in German psychophysics research) 15 years after  the mid-1990’s “consciousness boom”, interest remains strong.

Some among the talented  researchers who worked with Varela are still active, among them Jean-Phillipe Lachaux, as well as Antoine Lutz , who describes his research thusly:

“I am interested in understanding the neural counterparts to subjective experience and, more generally, the mechanisms underlying mind-brain-body interactions. In the first part of my research, I am studying the role of large-scale neuronal integration (neural synchrony mechanisms) during various mental states (voluntary attention, emotion generation); The emphasis of my work is in the use of introspective, or first-person, data in order to understand the function of these large-scale dynamical processes”

Among philosophers doing neurophenomenological research, there is Shaun Gallagher, who wrote the excellent How the Body Shapes the Mind, and who is  the Editor-in-Chief of the journal Phenomenology and the Cognitive SciencesDavid Casacuberta has a neurophenomenology website at http://neurophenomenology.blogspot.com/.

It is worth noting that there are more academic papers and books about embodied cognition than ever. Neurophenomenology in the narrower sense is somewhat in a transitional phase after the death of Varela, and it remains to be seen whether the component sub-fields of clinical neurology, neuropsychology, experimental cognitive neuroscience, and philosophy will continue to produce an emergent field.  However, there have been a number of works which are to this author stimulating and likely fertile sources of new ideas. In particular, Antonio Damasio’s 2010 Self Comes to Mind: Constructing the Conscious Brain seems as if it will usher in a new era of productive research on embodied cognition.

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This work focuses on the role of visceral dynamics in the body being mapped onto the brainstem, thalamus, insular and cingulated cortices, and other regions to generate a sort of representation of the homeostatic state of the body.

Evan Thompson has recently authored a wonderful, well written tome entitled Mind in Life. It refines and even critiques some of the arguments and perspectives from the 1980’s/early 1990’s era that produced The Embodied Mind:

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This has garnered high praise from no less an authority than neurodynamicist Walter Freeman:

“There is no deeper prison of the modern mind than the Cartesian legacy that splits mind from life, and no more arduous climb to escape. Thompson provides a topo map–rich, multifaceted, superbly documented–by detailing the work of the many (but relatively few among contemporary scientists and philosophers) who recognize the impasse and strive to transcend it.”

Interest in neurophenomenology is on the rise. As of mid-2009, Google lists 24,000 results under the term “neurophenomenology” .  In early 2013, there are more than 34,000. As one who can remember that a browser search in 1996 produced about 3 results, a sense of excitement is likely appropriate. The knotty challenges involved in this sort of research are daunting, but more people than ever are looking at the problems. We are, perhaps, at the end of the beginning of the story of research into neurophenomenology.

Part II of Leder’s The Absent Body

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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.

Excerpt from Drew Leder’s The Absent Body pt. 1

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Drew Leder is a physician and philosopher. His  1990 book The Absent Body is a tour-de-force!

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“According to a scheme employed in physiology, the body’s sensory powers can be divided into three categories. Interoception refers to all sensations of the viscera, that is, the internal organs of the body. It is usually distinguished both from exteroception, our five senses open to the external world, and proprioception, our sense of balance, position, and muscular tension, provided by receptors in muscles, join is, tendons, a ltd the inner ear. In this section I will describe three essential features that structure the interoceptive field; I will term these features respec­tively qualitative reduction, spatial ambiguity, and spatiotemporal disconti­nuity.

Qualitative reduction

Ordinarily that which enters the interoceptive field is simultaneously lost to the exteroceptive. Before swallowing the apple I can see, touch, smell, and taste it in all its crimson-tart vividness. Once swallowed, these possibilities are swallowed up as well I can occasion ally; and per­haps unpleasantly, bear or smell evidence of my digestive activity. As in the above example, I can even catch a taste via esophageal reflux. Yet aside from such intermittent and muted evidences, the incorporation of an object into the visceral space involves its withdrawal from exterocep­tive experience.

The perceptual field into which the object is received is limited com­pared to that of the surface body. Interoception does not share the multidimensionality of exteroception, the latter utilizes five sense-modalities which, though tightly interwoven in everyday praxis, have radically divergent spatiotemporal and qualitative properties. Interocep­tion is not devoid of an expressive range and utilizes, physiologists tell us, a variety of sense-receptor types, including mechanoreceptors, nociceptors, and even some thermoreceptors. Yet these are experienced as modulating a single dimension of perception, i.e., “inner sensation” rather  than opening onto distinct perceptual worlds.

Furthermore, the qualitative range of this dimension is reduced even when compared to any single exteroceptive mode. Touch, the most analogous form of surface perception, includes within it a huge variety of sensory statements. My acutely articulate skin yields a panoply of tickles, itches, pains, sensations of light and deep pressure, warmth and cold, slow and fast vibrations. The interoceptive vocabulary is not as well developed. In the above example, the stomach and intestines yield a feeling of fullness and cramping. The esophagus burns with an acid reflux. Yet this comes close to exhausting the ordinary sensory experi­ences of this region. In physiological terms, the viscera have a greatly decreased number and variety of sensory receptors compared to the Sur­face body, as well as a limited repertoire of motor responses. Experien­tially, one notices a certain crudeness and generality to most of the mes­sages received. This is a common problem for diagnosing physicians.

An experience of “tightness” in the chest could signal any of a number of cardiac, respiratory, muscular, or even alimentary difficulties, given the imprecision of interoception.

The limited interoceptive vocabulary largely centers around sensa­tions that are affectively charged. Through my outer-directed senses I can survey the exteroceptive field without immediate emotional re­sponse. The separation between the perceiver and the perceived makes possible a dispassionate scan. By contrast, visceral sensations grip me from within, often exerting an emotional insistence. As the example suggests, it is the discomforting or painful sensations that speak up most clearly: the crampy stomach, the heartburn, the insistent need for defe­cation. Like the infant who cries in displeasure but lapses into content­ment silently, the viscera seem most able and most articulate in relation to dysfunction (see chapter 3 below). The biological/existential signifi­cance of this is clear. It is at times of dysfunction that an insistent and aversive call is needed to compel reparatory action.

While my interoceptive vocabulary is thus most developed in relation to pain, it is limited even here when compared to the body surface. My skin is susceptible to the most exquisite and differentiated tortures if it is cut, burned, pricked, tickled, stretched, struck, pinched. The inner organs exhibit comparatively restricted modes of discomfort. A particu­lar viscus often has its stereotyped ways of responding to almost any noxious stimuli; stomach cramps can result from stress, infection, and food poisoning alike. Moreover, the same general sort of pain, often de­scribed as a diffuse aching or burning, is shared in common by many different viscera.

Spatial Ambiguity

Interoception is reduced compared to surface perception not only in its qualitative range but in its spatial precision. Vision, audition, and touch allow me to locate stimuli to a fine degree. My fingers can tell apart pinpricks separated by only one to two millimeters. While other regions of the surface are less discriminating, I usually have little difficulty in locating cutaneous sensations. By way of contrast, visceral sensations are often vaguely situated with indistinct borders. In my example, I experi­ence midsection fullness and cramps, but there is no clear place where they begin or end, and no precise center.

Pain can suddenly localize when the sensitive membranes lining the visceral cavities become involved. But the inner organs themselves are in many instances simply incapable of registering localized events. Sur­geons, for example, have found that they can cut the intestines in two without a conscious patient experiencing significant pain. Like other viscera, the intestines primarily report generalized stimulations involv­ing substantial portions of the organ.

The spatial ambiguity of the visceral depths is accentuated by the phenomenon of referred pain. A process taking place in one organ tan exponentially radiate to adjacent body areas or express itself in a distant location. Hence the pain of a heart attack may originate in the chest area but quickly spread down the left arm. This reflects embryological ori­gins; sensation is referred to that level of the body the viscus occupied in the developing fetus before it descended, dragging nerves along, to its mature position. Thus, I may experience the pain where the organ used to be, not simply where it is now. An almost magical transfer of experi­ence is effected along both spatial and temporal dimensions, weaving the inner body into an ambiguous space.

Moreover, there are physical/phenomenal transfers between any vi­tal organ and the body as a whole that further prohibit strict localization of visceral experience. Ricoeur refers to “this strange mixture of the lo­cal and the non-local” that is encountered in phenomena such as pain, hunger, thirst, and all vital needs,’ As the example indicates, hunger is experienced not just in abdominal ache but as heaviness in the limbs, a yearning in the mouth. The visceral organs sustain my body as a whole through processes of digestion, circulation, respiration, and excretion. Hence, when I manifest a visceral-based contentment or dysfunction, this is manifested everywhere and nowhere.  A twinge in the finger is clearly located there. But hunger is a complex nexus of heaviness, ex­haustion, conative urges, and discomforting sensations that, while gath­ering into nodes of crystallization, ambiguously inhabits the entirety of the corporeal field.

Body-knowledge: what is it?

embodiment, Francisco Varela, interoception, Uncategorized, visceral perception

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

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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?”

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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

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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).