In this article we discuss the molecular signaling mechanisms that coordinate interactions between Schwann cells and the neurons of the peripheral nervous system. Such interactions take place perpetually during development and in adulthood, and are critical for the homeostasis of the peripheral nervous system (PNS). Neurons provide essential signals to control Schwann cell functions, whereas Schwann cells promote neuronal survival and allow efficient transduction of action potentials. Deregulation of neuron–Schwann cell interactions often results in (...) developmental abnormalities and diseases. Recent investigations have shown that during development, neuronally provided signals, such as Neuregulin, Jagged, and Wnt interact to fine‐tune the Schwann cell lineage progression. In adult, the signal exchange between neurons and Schwann cells ensures proper nerve function and regeneration. Identification of the mechanisms of neuron–Schwann cell interactions is therefore essential for our understanding of the development, function and pathology of the peripheral nervous system as a whole. -/- . (shrink)

Philosophers of mind, both in the conceptual analysis tradition and in the empirical informed school, have been implicitly neglecting the potential conceptual role of the Peripheral Nervous System (PNS) in understanding sensory and perceptual states. Instead, the philosophical as well as the neuroscientific literature has been assuming that it is the Central Nervous System (CNS) alone, and more exactly the brain, that should prima facie be taken as conceptually and empirically crucial for a philosophical analysis (...) of such states This is the first monograph that focuses on the PNS and its constitutive role in sensory states, including pain, mechanoception, proprioception, tactile perception, and so forth. -/- The author argues that the brain-centeredness of current philosophy of mind is a prejudice, and proposes a series of original ways in which classic puzzles in the philosophy of mind can be solved once the hypothesis that PNS is a constitutive element of mental states is taken seriously. The author calls this “the Peripheral Mind Hypothesis”, and employs it in a vast range of issues, such as functionalism, physicalism, mental content, embodiment, as well as some issues in neuroethics. -/- Making equal use of conceptual analysis, empirical data from neuroscience, first-person phenomenological data, and philosophical speculation, this work offers a fresh look at, and novel solutions to many philosophical problems. (shrink)

The peripheral nervous system has classically been separated into a somatic division composed of both afferent and efferent pathways and an autonomic division containing only efferents. J. N. Langley, who codified this asymmetrical plan at the beginning of the twentieth century, considered different afferents, including visceral ones, as candidates for inclusion in his concept of the “autonomic nervous system”, but he finally excluded all candidates for lack of any distinguishing histological markers. Langley's classification has been (...) enormously influential in shaping modern ideas about both the structure and the function of the PNS. We survey recent information about the PNS and argue that many of the sensory neurons designated as “visceral” and “somatic” are in fact part of a histologically distinct group of afferents concerned primarily autonomic function. These afferents have traditionally been known as “small dark” neurons or B-neurons. In this target article we outline an association between autonomic and B-neurons based on ontogeny, cell phenotype, and functional relations, grouping them together as part of a common reflex system involved in homeostasis. This more parsimonious classification of the PNS, made possible by the identification of a group of afferents associated primarily with the ANS, avoids a number of confusions produced by the classical orientation. It may also have practical implications for an understanding of nociception, homeostatic reflexes, and the evolution of the nervous system. (shrink)

Hyperalgesia can arise from peripheral sensitization, on-going peripheral activation, and central plasticity. In the target article, coderre & katz argue that all three mechanisms contribute to hyperalgesia. In contrast, we believe that existing experimental evidence suggests that central plasticity plays only an insignificant role in most experimental models and clinical presentations of hyperalgesia induced by tissue injury or chemical activation of sensory receptors.

ABSTRACTThe idea that there can be only one cognitive system within any single given cognitive organism is an established albeit implicit one within cognitive science and related studies of the mind. The firm foothold of this notion is due largely to the immense corpus of empirical evidence for the correlation of a high level of cognitive sophistication with a centralized nervous system. However, it must be pointed out that these findings are sourced in large part from studies (...) on vertebrates. This paper presents a potential counterexample to the notion that only one cognitive system can be realized within any single genuine cognitive organism. This counterexample is the octopus, an invertebrate with what initially appears to be a paradoxical combination of vertebrate-like cognitive and behavioral capacities and a functionally decentralized nervous system. The extensive relegation of sensorimotor processing and control responsibilities to the peripheral nervous system which controls the arms of the octopus... (shrink)

The “brain in a vat” thought experiment is presented and refuted by appeal to the intuitiveness of what the author informally calls “the eye for an eye principle”, namely: Conscious mental states typically involved in sensory processes can conceivably successfully be brought about by direct stimulation of the brain, and in all such cases the utilized stimulus field will be in the relevant sense equivalent to the actual PNS or part of it thereof. In the second section, four classic problems (...) of Functionalism are given novel solutions based on the inclusion of peripheral nervous processes as constituents of mental states: The mad pain problem, the problem of pseudo-normal vision, the China-brain problem, and the triviality problem. (shrink)

The author presents an autobiographical story of serious peripheral motor nerve damage resulting from chemotoxicity induced as a side effect of Hodgkin’s Lymphoma treatment. The first-person, phenomenological account of the condition naturally leads to philosophical questions about consciousness, felt presence of oneself all over and within one’s body, and the felt constitutiveness of peripheral processes to one’s mental life. The first-person data only fit well with a philosophical approach to the mind that takes peripheral, bodily events and (...) states at their face value, and not as a body-in-the-brain, which has been popular with most neuroscientists. Thus the philosophical tradition that comes closest to the idea of the peripheral mind is Maurice Merleau-Ponty’s bodily phenomenology. (shrink)

O presente estudo examinou a relação entre aspectos psicossociais e padrões de reação fisiológica (frequência cardíaca, pressão arterial, condução cutânea e medidas respiratórias) para quatro tipos de contingências operantes (recompensa, extinção, punição e evitação) registrados durante um teste de ..

The study of the autonomic nervous system (ANS) function has shown to provide useful indicators for risk stratification and early detection on a variety of cardiovascular pathologies. However, data gathered during different tests of the ANS are difficult to analyse, mainly due to the complex mechanisms involved in the autonomic regulation of the cardiovascular system (CVS). Although model-based analysis of ANS data has been already proposed as a way to cope with this complexity, only a few models (...) coupling the main elements involved have been presented in the literature. In this paper, a new model of the CVS, representing the ventricles, the circulatory system and the regulation of the CVS activity by the ANS, is presented. The models of the vascular system and the ventricular activity have been developed using the Bond Graph formalism, as it proposes a unified representation for all energetic domains, facilitating the integration of mechanic and hydraulic phenomena. In order to take into account the electro-mechanical behaviour of both ventricles, an electrophysiologic model of the cardiac action potential, represented by a set of ordinary differential equations, has been integrated. The short-term ANS regulation of heart rate, cardiac contractility and peripheral vasoconstriction is represented by means of continuous transfer functions. These models, represented in different continuous formalisms, are coupled by using a multi-formalism simulation library. Results are presented for two different autonomic tests, namely the Tilt Test and the Valsalva Manoeuvre, by comparing real and simulated signals. (shrink)

In many evolutionary/functionalist theories, emotions organize the activity of the autonomic nervous system and other physiological systems. Two kinds of patterned activity are discussed: coherence, and specificity. For each kind of patterning, significant methodological obstacles are considered that need to be overcome before empirical studies can adequately test theories and resolve controversies. Finally, links that coherence and specificity have with health and well-being are considered.

What is the primary function of consciousness in the nervous system? The answer to this question remains enigmatic, not so much because of a lack of relevant data, but because of the lack of a conceptual framework with which to interpret the data. To this end, we have developed Passive Frame Theory, an internally coherent framework that, from an action-based perspective, synthesizes empirically supported hypotheses from diverse fields of investigation. The theory proposes that the primary function of consciousness (...) is well-circumscribed, serving the 'somatic nervous system[. For this system, consciousness serves as a frame that constrains and directs skeletal muscle output, thereby yielding adaptive behavior. The mechanism by which consciousness achieves this is more counterintuitive, passive, and “low level” than the kinds of functions that theorists have previously attributed to consciousness. Passive frame theory begins to illuminate (a) what consciousness contributes to nervous function, (b) how consciousness achieves this function, and (c) the neuroanatomical substrates of conscious processes. Our untraditional, action-based perspective focuses on olfaction instead of on vision and is 'descriptive' (describing the products of nature as they evolved to be) rather than 'normative' (construing processes in terms of how they should function). Passive frame theory begins to isolate the neuroanatomical, cognitive-mechanistic, and representational (e.g., conscious contents) processes associated with consciousness. (shrink)

In many evolutionary/functionalist theories, emotions organize the activity of the autonomic nervous system and other physiological systems. Two kinds of patterned activity are discussed: coherence, and specificity. For each kind of patterning, significant methodological obstacles are considered that need to be overcome before empirical studies can adequately test theories and resolve controversies. Finally, links that coherence and specificity have with health and well-being are considered.

The objective of this paper is to present a new theory of synaptic function in the nervous system. The basis for this theory is the experimental demonstration that a nerve impulse assumes five different forms as it advances through the synaptic region, and that five basic mathematical operations have been identified as being involved in the transformation of one form into another form. As a result of these data, the synaptic region is regarded as a functional unit where (...) information coming to it is unpacked, processed, stored, and retrieved for transit to another synaptic region or effector site. The data also suggests that a nerve impulse is a bolus of energy, therefore, without substance; that it contains information coded in its shape or form; that it is precisely described mathematically. Furthermore, the data suggests synaptic regions process these nerve impulses by applying mathematical operations to them; that function in the synaptic region is highly stereotyped (programmed); that chemical substances are associated with the mathematical operations. The basic approach of this theory is to regard a significant portion of the nervous system as an interface between the external universe and man himself. As an interface, the nervous system receives and processes information from both the external universe and man himself in a programmed manner. The interface functions by converting the information it receives into a bolus of energy, the nerve impulse, then processes the bolus by converting it into numbers or functions and applying mathematical operation to it. (shrink)

What is it like to be an octopus, one of those eight-armed, infinitely flexible sea creatures with a nervous system distributed over head, eyes and arms? One interesting approach is to argue that octopuses, because of their distributed nervous systems, are likely to possess disunified consciousness (Carls-Diamante 2017). However, this supposed isomorphism between a “unified” nervous system and “unified” consciousness is problematic, since the term “unity” is taken as a “given” even though it is far (...) from clear what it means. I will argue that explaining the structure of consciousness requires a prior explanation in terms of how it is achieved by the organism through sensorimotor integration. On this account, the structure of an organism’s consciousness is explained partly by what the external world is like, and partly by how the organism’s body, senses and nervous system enable the organism to interact with the external world. (shrink)

The target article discusses various aspects of the relationship between the sympathetic system and pain. To this end, the patients under study are divided into three groups. In the first group, called (RSD), the syndrome can be characterized by a triad of autonomic, motor, and sensory symptoms, which occur in a distally generalized distribution. The pain is typically felt deeply and diffusely, has an orthostatic component, and is suppressed by the ischemia test. Under those circumstances, the pain is likely (...) to respond to sympatholytic interventions. In a second group, called (SMP) syndrome, the principal symptoms are spontaneous pain, which is felt superficially and has no orthostatic component, and allodynia. These symptoms, typically confined to the zone of a lesioned nerve, may also be relieved by sympathetic blocks. Since the characteristics of the pain differ between RSD and SMP, the underlying kind of sympathetic–sensory coupling may also vary between these cases. A very small third group of patients exhibits symptoms of both RSD and SMP. The dependence or independence of pain on sympathetic function reported in most published studies seems to be questionable because the degree of technical success of the block remains uncertain. Therefore, pain should not be reported as sympathetic function independent until the criteria for a complete sympathetic block have been established and satisfied. (shrink)

The article considers patterns of reactivity in organ systems mediated by the autonomic nervous system as they relate to central neural circuits activated by affectively arousing cues. The relationship of these data to the concept of discrete emotion and their relevance for the autonomic feedback hypothesis are discussed. Research both with animal and human participants is considered and implications drawn for new directions in emotion science. It is suggested that the proposed brain-based view has a greater potential for (...) scientific advance than the traditional model that emphasizes specific states of mind as mediators or reflectors of visceral action. (shrink)

Brazilian spiritistic religions have developed along elaborate historical and cultural trajectories with spirit mediumship as a central feature of ritual practice in Candomblé, Umbanda, Kardecismo, and similar groups. In these studies, several Brazilian spiritistic practitioners who worked as mediums were interviewed and, in some cases, tested with psychological measures for dissociation using the Dissociative Experiences Scale, for absorption using the Tellegen Absorption Scale, and for sexual orientation using the Kinsey Scale. Few significant gender differences were noted in these measures. In (...) two cases, psychophysiological measures were employed including electroencephalography, heart rate, skin conductance, and electromyography. In general, the research participants scored highly on measures of dissociation while scoring in the average range on absorption (using U.S. norms). The psychophysiological results indicated that for the two spiritistic practitioners investigated overall peripheral autonomic nervous system activation was negatively associated with sympathetic cortical level deactivation. The data suggested a psychophysiological incongruence between the central nervous system and the peripheral nervous system functioning on the part of the two practitioners. However, the two variables were positively associated and congruent in data obtained from a control subject. Interview data identified five ways in which mediums received their "call to heal," visions, dreams, and unexpected incorporations being the most frequent factors cited. One medium who engages in surgical procedures was observed; tissues were collected from ten clients and were found to be consistent with the site of the surgery. In conclusion, it is apparent that mediumship is a complex phenomenon, one deserving of further investigation by anthropologists, psychologists, and sociologists interested in human consciousness, in indigenous health care, and in the psychophysiology of practitioners who claim to work under the direction of spirit entities. (shrink)

Here we evaluate our current understanding of the function of the nervous system in Hydra, a non‐bilaterian animal which is among the first metazoans that contain neurons. We highlight growing evidence that the nervous system, with its rich repertoire of neuropeptides, is involved in controlling resident beneficial microbes. We also review observations that indicate that microbes affect the animal's behavior by directly interfering with neuronal receptors. These findings provide new insight into the original role of the (...) nervous system, and suggest that it emerged to orchestrate multiple functions including host‐microbiome interactions. The excitement of future research in the Hydra model now relies on uncovering the common rules and principles that govern the interaction between neurons and microbes and the extent to which such laws might apply to other and more complex organisms. (shrink)

This commentary on blumberg et al. addresses complications associated with diagnostic testing for sympathetic dependence of pain that can lead to inappropriate positive and negative conclusions. In addition, it is suggested that their test be conceived as a test of the effect of local vascular pressure and that the two types of sensory disorders presented may differ primarily in the degree of sensitization of central pain pathways. Detailed reports with functionally-oriented testing like that done by BLUMBERG are essential for an (...) understanding the pathophysiological mechanisms. (shrink)

Grush has proposed a fairly comprehensive version of the idea of internal models within the framework of the emulation theory of representation. However, the formulation suffers from assumptions that render such models biologically infeasible. Here I present some problems from physiological principles of human movement production to illustrate why. Some alternative views to emulation are presented.

The first paper in this pair developed a model of the nature of representation and cognition, and argued for a model of the micro-functioning of the brain on the basis of that model. In this sequel paper, starting with part III, this model is extended to address macro-functioning in the CNS. In part IV, I offer a discussion of an approach to brain functioning that has some similarities with, as well as differences from, the model presented here: sometimes called the (...) Predictive Brain approach. (shrink)

Standard semantic information processing models—information in; information processed; information out —lend themselves to standard models of the functioning of the brain in terms, e.g., of threshold-switch neurons connected via classical synapses. That is, in terms of sophisticated descendants of McCulloch and Pitts models. I argue that both the cognition and the brain sides of this framework are incorrect: cognition and thought are not constituted as forms of semantic information processing, and the brain does not function in terms of passive input (...) processing units organized as neural nets. An alternative framework is developed that models cognition and thought not in terms of semantic information processing, and, correspondingly, models brain functional processes also not in terms of semantic information processing. As alternative to such models: I outline a pragmatist oriented, interaction based, model of representation; derive from this model a fundamental framework of constraints on how the brain must function; show that such a framework is in fact found in the brain, and develop the outlines of a broader model of how mental processes can be realized within this alternative framework. Part I of this discussion focuses on some criticisms of standard modeling frameworks for representation and cognition, and outlines an alternative interactivist, pragmatist oriented, model. In part II, the focus is on the fact that the brain does not, in fact, function in accordance with standard passive input processing models—e.g., information processing models. Instead, there are multiple endogenously active processes at multiple spatial and temporal scales across multiple kinds of cells. A micro-functional model that accounts for, and even predicts, these multi-scale phenomena in generating emergent representation and cognition is outlined. That is, I argue that the interactivist model of representation outlined offers constraints on how the brain should function that are in fact empirically found, and, in reverse, that the multifarious details of brain functioning entail the pragmatist representational model—a very strong interrelationship. In the sequel paper, starting with part III, this model is extended to address macro-functioning in the CNS. In part IV, I offer a discussion of an approach to brain functioning that has some similarities with, as well as differences from, the model presented here: sometimes called the predictive brain approach. (shrink)

This article proposes a novel approach to bioethics, referred to as “affective bioethics”, which draws on traditions in anthropology, science and technology studies, disability studies, and Spinozist materialism. By focusing on the case of Michael and Terri Schiavo, in which Terri’s personhood and subjectivity are challenged by dominant forms of neurological reductivism in the USA, this article suggests that approaching her condition as a set of relations with the people in her life and her socio-technical environment may have helped to (...) develop new ways to conceptualise personhood and subjectivity moving beyond the view of her as a non-person. Drawing on Michael Schiavo’s memoir of his legal battles, and Terri’s diagnosis and care, this article shows how Terri’s connections to the world disrupt American ideas about the isolatable individual as the basis for personhood and subjectivity. Attending to these interpersonal and socio-technical connections focuses bioethical attention on the worlds that individuals inhabit, and how those worlds might be designed to make more kinds of life livable and new forms of personhood and subjectivity possible. (shrink)

This paper brings together two erstwhile distinct strands of philosophical inquiry: the extended mind hypothesis and the situationist challenge to virtue theory. According to proponents of the extended mind hypothesis, the vehicles of at least some mental states (beliefs, desires, emotions) are not located solely within the confines of the nervous system (central or peripheral) or even the skin of the agent whose states they are. When external props, tools, and other systems are suitably integrated into the (...) functional apparatus of the agent, they are partial bearers of her cognitions, motivations, memories, and so on. According to proponents of the situationist challenge to virtue theory, dispositions located solely within the confines of the nervous system (central or peripheral) or even the skin of the agent to whom they are attributed typically do not meet the normative standards associated with either virtue or vice (moral, epistemic, or otherwise) because they are too susceptible to moderating external variables, such as mood modulators, ambient sensibilia, and social expectation signaling. We here draw on both of these literatures to formulate two novel views – the embedded and extended character hypotheses – according to which the vehicles of not just mental states but longer-lasting, wider-ranging, and normatively-evaluable agentic dispositions are sometimes located partially beyond the confines of the agent’s skin. (shrink)