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)

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)

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)

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)

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.

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)

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)

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)

Title page Representational theories propose a set of sufficient conditions for a state to be phenomenally conscious. It turns out that insofar as these conditions have been worked out in detail, the autonomic nervous system (ANS) ought to be conscious - but of course it’s not. In this paper, we’ll describe only a tiny portion of the complexities of the ANS, using these to counterexample only a single theory of phenomenal consciousness, namely, Fred Dretske’s. But we think the (...) ANS comparison strategy is a fruitful one in general, and we hope to convince you of this too. (shrink)

In this paper, my aim is to understand the origin of experimental and scientific models of pathogeny of the diseases of the nervous system in the Salpêtrière (Paris). I will analyse the role of the contexts of cell theory, microscopy and the advances in histological techniques in the creation of various pathogenic models, based on the concept of the cell, the Wallerian degeneration and the neurone concept. I argue that, as medicine and pathology remain autonomous in their methods (...) and goals, because of the evident degree of complexity of diseases, close and reciprocal interactions with sciences, their practices and theories, make it possible to establish convergences between clinical observations, pathological data and those from the experimental models of pathologies. The search for pathogenic models behaves like an engine, which is efficient in assembling facts, in testing pathogeneses and reforming nosologies, combined with the breakthroughs in biology. This paper is a case study showing the emergence of such interactions in the last decades of the nineteenth-century in Paris. (shrink)

A new theory for basic function in the nervous system has recently been proposed (Dempsher, J., 1979a, 1979b; 1980, 1981). The major basic themes of the new theory are as follows: (1) There are two fundamental units of structure and function, the fibre or conducting mechanism, and the neurocentre, where nervous system function as we know it takes place. (2) The nerve impulse is regarded as a mathematical event. The mathematics is the result of a prescribed (...) fusion of energy and matter. (3) Nervous system function everywhere in the nervous system is mathematical. In the fibre, the prescribed fusion of energy and matter results in a number. In the neurocentre, the prescribed fusion of energy and matter results in a mathematical function. Basic function in the nervous system everywhere requires a transformation of a nerve impulse in the fibre into a nerve impulse in the neurocentre with opposing properties: The nerve impulse in the fibre is confined to the fibre; cannot sum with another nerve impulse; can travel long distances with constant form and velocity; curvature in space and time are not significant features; and it is regarded as a number. On the other hand, the nerve impulse in the neurocentre is confined to the neurocentre; can sum with other nerve impulses; cannot travel long distances - even in a very short distance, it changes form; curvature in space and time is a very significant feature; and it is regarded as a mathematical function.The approach to determine how one form of the nerve impulse is transformed into the other at the input region is based on two of the differences listed above: (1) The nerve impulse in the fibre cannot sum with another nerve impulse in the fibre, whereas in the neurocentre, several nerve impulses sum to form a larger nerve impulse. (2) The nerve impulse in the fibre is regarded as a number, in the neurocentre, it is regarded as a mathematical function. The commonality of (1) and (2) is that the properties defining the nerve impulse in the fibre are associated with the property ofdiscreteness, whereas, the properties defining the nerve impulse in the neurocentre are associated with the property ofcontinuousness. Thus, the basic theme of unification of function at the input region of the neurocentre is the transformation of a phenomenon with the property of discreteness into a phenomenon with the property of continuousness. The solution to this transformation is approached from two directions:biologic andmathematical. In the biologic approach, the unit element of the nerve impulse in the fibre terminations (as.u. as a wave of energy, a spike in the classical theory) fuses with a. calcium-binding protein causing the release of Ca++. The calcium ions then combine with another protein. Associated with the second reaction is a conformational change in the Ca++-protein complex and the unit element in the neurocentre, bs.u., is emitted. Individual bs.u. then fuse with acetylcholine; summation occurs andwave b is emitted. In the mathematical approach, the nerve impulse as a number, is partitioned into two numbers with a precise rule relating these two numbers. One possibility suggested is that the number can be regarded as the value of a trigonometric function. This value then gives rise to an angle with sides related in a ratio or proportionality fashion — a relationship with the property of continuousness, as contrasted with that of a single number, discreteness. Both biologic and mathematical approaches are united so as to suggest that the mathematical (trigonometric) function arose as the result of a fusion of energy (as.u. as a wave of energy) and the calcium-binding protein as matter; following this reaction, bs.u., with opposing properties, is emitted. (shrink)

The purpose of this paper is to present a bio-physical basis of mathematics. The essence of the theory is that function in the nervous system is mathematical. The mathematics arises as a result of the interaction of energy (a wave with a precise curvature in space and time) and matter (a molecular or ionic structure with a precise form in space and time). In this interaction, both energy and matter play an active role. That is, the interaction results (...) in a change in form of both energy and matter. There are at least six mathematical operations in a simple synaptic region. It is believed the form of both energy and matter are specific, and their interaction is specific, that is, function in most of the nervous system is stereotyped. It is suggested that mathematics be taken out of the mind and placed where it belongs — in nature and the synaptic regions of the nervous system; it results in both places from a precise interaction between energy (in a precise form) and matter (in a precise structure). (shrink)

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)

A new theory of synaptic function in the nervous system (Dempsher, 1978) is applied to the simplest system for integration of function in the nervous system. This system includes a sensory and motor neuron and three synaptic regions associated with those two neurons; a receptor region, an interneuronal spinal synaptic region linking the two neurons, and an effector region.Information is first received and processed at the receptor region. The processing consists of five components:1. A (...) highly selective mechanism which allows only that information to enter the receptor system which is appropriate. 2. The appropriateness of the information is determined by the alphabet (miniature potentials) already in that area. 3. The information entering the system is assembled in a pattern meaningful for the next processing operation. 4. The assembled information is then disassembled into its subunits and mapped into the alphabet (miniature potentials). 5. These miniature potentials are assembled into another pattern meaningful to fit the role of the receptor region. 6. This new pattern is repacked for transit to the central synaptic region. (shrink)

Neuro-technical interfaces are technical devices that bridge the electronic world to neurons with the objective to establish a long term stable contact for bidirectional information exchange. What does that mean in detail and to what kind of machine and for what purpose should the central nervous system, i.e. the brain, be connected? Science fiction literature and movies offer a tremendous variety of usually uncomfortable scenarios including cyborg and robocop super-humans and mass control. Do these implants change the psyche (...) in general and what is feasible in nowadays therapeutic and rehabilitative approaches? In this overview, the author will not answer these questions but tries to deliver an overview of the technological background, the opportunities and the limitations of neuro-technical interfaces to the central nervous system. The fundamental specifications for neuro-technical interfaces will be introduced. Different degrees of implant invasiveness will be discussed and lead to a summary of clinical systems with their application-specific complexity. Actual technological opportunities and limitations will be addressed as well as general physical limitations. Current and future scenarios of neuro-technical interfaces to the central nervous system will be presented from an engineering point of view arising some questions that might be of interest with respect to ethical and societal implications when those interfaces are transferred into clinical practice and public applications. (shrink)

Fezf1 and Fezf2 are highly conserved transcription factors that were first identified by their specific expression in the anterior neuroepithelium of Xenopus and zebrafish embryos. These proteins share an N‐terminal domain with homology to the canonical engrailed repressor motif and a C‐terminal DNA binding domain containing six C2H2 zinc‐finger repeats. Over a decade of study indicates that the Fez proteins play critical roles during nervous system development in species as diverse as fruit flies and mice. Herein we discuss (...) recent progress in understanding the functions of Fezf1 and Fezf2 in neurogenesis and cell fate specification during mammalian nervous system development. Going forward we believe that efforts should focus on understanding how expression of these factors is precisely regulated, and on identifying target DNA sequences and interacting partners. Such knowledge may reveal the mechanisms by which Fezf1 and Fezf2 accomplish both independent and redundant functions across diverse tissue and cell types. (shrink)

The controversy of neuroanatomy on the principal structure of the nervous systems, which took place at the end of the nineteenth century, is described. Two groups of scientists are identified: one that favoured the idea of a discrete cellular organization of the nervous tissue, and one that favoured a syncytial organization. These two interpretations arose from different histological techniques that produced conflicting pictures of the organization of the nervous tissue. In an experimental reexamination of the techniques used (...) at the end of the nineteenth century, the present study concerns the impact of these different histological procedures on the controversy about the principle nature of the nervous tissue. This controversy could not be resolved by neuroanatomy itself until the 1950s when electron microscopy was introduced into neurobiology. Thus, in a critical period of the conceptual development of neurosciences, neuroanatomy failed to establish a proper base for an interpretation of the functional morphology of nervous tissues. (shrink)

Chaos theory is a rapidly growing field. As a technical term, chaos refers to deterministic but unpredictable processes being sensitively dependent upon initial conditions. Neurobiological models and experimental results are very complicated and some research groups have tried to pursue the neuronal chaos. Babloyantz's group has studied the fractal dimension (d) of electroencephalograms (EEG) in various physiological and pathological states. From deep sleep (d=4) to full awakening (d>8), a hierarchy of strange attractors paralles the hierarchy of states of consciousness. In (...) epilepsy (petit mal), despite the turbulent aspect of a seizure, the attractor dimension was near to 2. In Creutzfeld-Jacob disease, the regular EEG activity corresponded to an attractor dimension less than the one measured in deep sleep. Is it healthy to be chaotic? An active desynchronisation could be favourable to a physiological system. Rapp's group reported variations of fractal dimension according to particular tasks. During a mental arithmetic task, this dimension increased. In another task, a P300 fractal index decreased when a target was identified. It is clear that the EEG is not representing noise. Its underlying dynamics depends on only a few degrees of freedom despite yet it is difficult to compute accurately the relevant parameters.What is the cognitive role of such a chaotic dynamics? Freeman has studied the olfactory bulb in rabbits and rats for 15 years. Multi-electrode recordings of a few mm2 showed a chaotic hierarchy from deep anaesthesia to alert state. When an animal identified a previously learned odour, the fractal dimension of the dynamics dropped off (near limit cycles). The chaotic activity corresponding to an alert-and-waiting state seems to be a field of all possibilities and a focused activity corresponds to a reduction of the attractor in state space. For a couple of years, Freeman has developed a model of the olfactory bulb-cortex system. The behaviour of the simple model without learning was quite similar to the real behaviour and a model with learning is developed. (shrink)

A vast network of cellular circadian clocks regulates 24‐hour rhythms of behavior and physiology in mammals. Complex environments are characterized by multiple, and often conflicting time signals demanding flexible mechanisms of adaptation of endogenous rhythms to external time. Traditionally this process of circadian entrainment has been conceptualized in a hierarchical scheme with a light‐reset master pacemaker residing in the hypothalamus that subsequently aligns subordinate peripheral clocks with each other and with external time. Here we review new experiments using conditional (...) mouse genetics suggesting that resetting of the circadian system occurs in a more “federated” and tissue‐specific fashion, which allows for increased noise resistance and plasticity of circadian timekeeping under natural conditions. (shrink)

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)