Aus dem vielfältigen Werk von Hermann von Helmholtz versammelt diese Ausgabe die im engeren Sinne philosophischen Abhandlungen, vor allem zur Wissenschaftsphilosophie und Erkenntnistheorie, sowie Vorträge und Reden, bei denen der Autor seine Ausnahmestellung im Wissenschaftsbetrieb nutzte, um die Wissenschaften und ihre Institutionen in der bestehenden Form zu repräsentieren und zu begründen. Ein Philosoph wollte Helmholtz nicht sein, aber er legte der philosophischen Reflexion wissenschaftlicher Erkenntnis und wissenschaftlichen Handelns große Bedeutung bei. Vor allem bezog er, in der Regel ausgehend von seinen (...) fachwissenschaftlichen Forschungen, in den verschiedensten Kontexten zu erkenntnistheoretischen und methodologischen Problemen der Wissenschaften Stellung. Bereits »Ueber die Erhaltung der Kraft« (1847) lässt erkennen, wie verwoben naturwissenschaftliche Grundlagenforschung und philosophische Grundlagenreflexion in seinem Werk sind. Die aus den frühen sinnesphysiologischen Forschungen hervorgegangene empiristische Wahrnehmungslehre trug ihm den Ruf ein, ein maßgeblicher Vertreter des Neukantianismus zu sein. Spätere Arbeiten v.a. zur Geometrie und Arithmetik – das zeigt die vorliegende Ausgabe – stellen jedoch eine radikale Absage an den konstitutiven Kern des Kantianismus (nämlich die Existenz synthetischer Urteile a priori) dar. Helmholtz’ philosophische Beiträge sind bisher in ihrer Vollständigkeit nicht annähernd so gut zugänglich wie sein naturwissenschaftliches Werk. Die Ausgabe enthält außerdem bibliographische Vorberichte zur Einordnung, detaillierte Namens- und Sachregister sowie mit 575 Einträgen für den Zeitraum zwischen 1842 und 2012 die erste umfassende Bibliographie von Helmholtz verfasster Werke überhaupt. »Ich glaube, dass der Philosophie nur wieder aufzuhelfen ist, wenn sie sich mit Ernst und Eifer der Untersuchung der Erkenntnissprocesse und der wissenschaftlichen Methode zuwendet. Da hat sie eine wirkliche und berechtigte Aufgabe.« Helmholtz in einem Brief um 1875. (shrink)

This article seeks the origin, in the theories of Ibn al-Haytham (Alhazen), Descartes, and Berkeley, of two-stage theories of spatial perception, which hold that visual perception involves both an immediate representation of the proximal stimulus in a two-dimensional ‘‘sensory core’’ and also a subsequent perception of the three dimensional world. The works of Ibn al-Haytham, Descartes, and Berkeley already frame the major theoretical options that guided visual theory into the twentieth century. The field of visual perception was the first (...) area of what we now call psychology to apply mathematics, through geometrical models as used by Euclid, Ptolemy, Ibn al-Haytham, and Descartes (among others). The article shows that Kepler’s discovery of the retinal image, which revolutionized visual anatomy and entailed fundamental changes in visual physiology, did not alter the basic structure of theories of spatial vision. These changes in visual physiology are advanced especially in Descartes' Dioptrics and his L'Homme. Berkeley develops a radically empirist theory vision, according to which visual perception of depth is learned through associative processes that rely on the sense of touch. But Descartes and Berkeley share the assertion that there is a two-dimensional sensory core that is in principle available to consciousness. They also share the observation that we don't usually perceived this core, but find depth and distance to be phenomenally immediate, a point they struggle to accommodate theoretically. If our interpretation is correct, it was not a change in the theory of the psychology of vision that engendered the idea of a sensory core, but rather the introduction of the theory into a new metaphysical context. (shrink)

Introduction & Objectives: Norwich’s Entropy Theory of Perception (1975 [1] -present) stands alone. It explains many firing-rate behaviors and psychophysical laws from bare theory. To do so, it demands a unique sort of interaction between receptor and brain, one that Norwich never substantiated. Can it now be confirmed, given the accumulation of empirical sensory neuroscience? Background: Norwich conjoined sensation and a mathematical model of communication, Shannon’s Information Theory, as follows: “In the entropic view of sensation, magnitude of sensation is (...) regarded as a measure of the entropy or uncertainty of the stimulus signal” [2]. “To be uncertain about the outcome of an event, one must first be aware of a set of alternative outcomes” [3]. “The entropy-establishing process begins with the generation of a [internal] sensory signal by the stimulus generator. This is followed by receipt of the [external] stimulus by the sensory receptor, transmission of action potentials by the sensory neurons, and finally recapture of the [response to the internal] signal by the generator” [4]. The latter “recapture” differentiates external from internal stimuli. The hypothetical “stimulus generators” are internal emitters, that generate photons in vision, audible sounds in audition (to Norwich, the spontaneous otoacoustic emissions [SOAEs]), “temperatures in excess of local skin temperature” in skin temperature sensation [4], etc. Method (1): Several decades of empirical sensory physiology literature was scrutinized for internal “stimulus generators”. Results (1): Spontaneous photopigment isomerization (“dark light”) does not involve visible light. SOAEs are electromechanical basilar-membrane artefacts that rarely produce audible tones. The skin’s temperature sensors do not raise skin temperature, etc. Method (2): The putative action of the brain-and-sensory-receptor loop was carefully reexamined. Results (2): The sensory receptor allegedly “perceives”, experiences “awareness”, possesses “memory”, and has a “mind”. But those traits describe the whole human. The receptor, thus anthropomorphized, must therefore contain its own perceptual loop, containing a receptor, containing a perceptual loop, etc. Summary & Conclusions: The Entropy Theory demands sensory awareness of alternatives, through an imagined brain-and-sensory-receptor loop containing internal “stimulus generators”. But (1) no internal “stimulus generators” seem to exist and (2) the loop would be the outermost of an infinite nesting of identical loops. (shrink)

The physiologist Johannes Müller’s doctrine of specific nerve energies had a decisive influence on neo-Kantian conceptions of the objectivity of knowledge in the 1850s - 1870s. In the first half of the nineteenth century, Müller amassed a body of experimental evidence to support his doctrine, according to which the character of our sensations is determined by the structures of our own sensory nerves, and not by the external objects that cause the sensations. Neo-Kantians such as Hermann von Helmholtz, F.A. (...) Lange, and Otto Liebmann took Müller’s doctrine to have far-reaching consequences for their epistemologies. Over the course of the 1850s - 1870s, these three neo-Kantians, each in his own way, argued that reflection on Müller’s doctrine ruled out a certain conception of the objectivity of knowledge. It ruled out the view that knowledge is objective in virtue of affording us information about objects in a mind-independent external world. -/- This paper traces how Helmholtz, Lange, and Liebmann developed their arguments for this view, and how each developed his own alternative conception of objectivity, according to which objectivity has nothing to do with a mind-independent world. Finally, the paper concludes by considering why these arguments modelled on Müller’s doctrine would have been so powerful against rival post-Hegelian conceptions of objectivity, especially those of scientific materialists like Ludwig Büchner. (shrink)

Ornament is a valuable component in any architecture of buildings and cities that aims to connect to human beings. The suppression of ornament, on the other hand, results in alien forms that generate physiological and psychological distress. Early twentieth-century architects proposed major stylistic changes — now universally adopted — without having a full understanding of how the human eye/brain system works.

This project begins with the selective sensory experience suggested by lngarden followed by an insensitivity he insinuates to digestive processes. This is juxtaposed with an oenological explanation of phenomenal sedimentation offered by Jean-Luc Marion. It compares the dynamics of time in the former with the those of wine in the latter. Emphasis is given to lngarden's insinuation of time as fluid, liquid, or aquatic. It revisits Ingarden's physiological explanations of partially-open systems by way of the bilateral excretion and absorption (...) of semi-permeable cellular membranes. The importance he eventually grants to inner secretion is considered alongside perspiration and salivation collateral to skin and membranes. It suggests that Ingarden's interest in thermoregulation, partial permeation, and secretion invites alternative conceptions of temporal consciousness in physiological experiences, beyond sequential and linear clock-time and/or Kantian intuition. Temporality experienced as temperance becomes discernible at a permeable point in which the sedimentation of Husserl, the maturation of Marion, and the fluidity and secretion of Ingarden mix and mingle into the taste of time. (shrink)

A physical model was utilized to show that the neural system can memorize a target position and is able to cause motor and sensory events that move the arm to a target with more accuracy. However, this cannot indicate in which coordinates the necessary computations are carried out. Turning off the lights causes the error to increase which is accomplished by cutting off one feedback path. The geometrical properties of arm kinematics and the properties of the kinesthetic and visual (...) sensorial systems should be better known before inferences about higher levels of processing can be drawn. (shrink)

This article considers Helmholtz’s relation to philosophy, including Fichte’s philosophy. Recent interpreters find Fichtean influence on Helmholtz, especially concerning the role of voluntary movement in distinguishing subject from object, or “I” from “not-I.” After examining Helmholtz’s statements about Fichte, the article describes Fichte’s ego-doctrine and asks whether Helmholtz could accept it into his sensory psychology. He could not accept Fichte’s core position, that an intrinsically active I intellectually intuits its own activity and posits the not-I as limiting and determining (...) that activity, because that account requires cognitive abilities that conflict with Helmholtz’s claim that the development of spatial perception relies primarily on associative memory and involves no direct awareness of the ego’s activity as such. Helmholtz would have known various accounts of the distinction between subject and object, or self and world, from sensory physiology, including associative accounts invoking voluntary motor movements and accounts describing checks on the perceiver’s activity. Some of the accounts cite Fichte on the I and not-I, but most do not, and none adopt Fichte’s Idealism. Finally, the article examines Helmholtz’s relation to metaphysics, finding that in all periods he rejected Fichtean Idealism and that the modest metaphysics of his mature period is a version of structural realism. (shrink)

The physiological constraints of our neuro-sensory instrumentation limit the information we receive and from which we fashion our impressions. These limitations precede the psychological issues of data generation and analysis described by Ioannidis [1]. Scientific models widely accepted for at least 50 years [2,3] suggest that the peripheral and central nervous systems do not provide direct information about phenomena as they exist in nature. Instead, perceptible phenomena stimulate sense organs to produce nerve impulses. Sensory nerve impulses are not (...) replicas of the phenomena stimulating their production. The brain, by obscure mechanisms, then fabricates personal experience from the sensory nerve impulses. The relationship of phenomena to the brain's experiential construct is unknown. Since evidence is produced by sense organs and the brain (neither of which incorporates bona fide replicas of phenomena), all scientific conclusions are likely false in the sense that they are not based on direct knowledge of phenomena as they exist in nature. (shrink)

Lilly was one of the greatest scientists and pioneers on the limits of human possibility but after his death a collective amnesia has descended and he is now almost forgotten. His Wiki is good but inevitably incomplete so here are a few missing details and viewpoints. Lilly was a generation (or more) ahead of his time. He is almost single-handedly responsible for the great interest in dolphins (which led to the Marine Mammal Protection Act in the USA and helped to (...) found the animal rights movement). In 1958 he noted that the brains of elephants and cetaceans were larger than ours, that we should not abuse them and that it was one our most important projects to communicate with them. He invented sensory isolation tanks (at NIMH in 1954) and used them extensively with and without powerful psychoactive drugs at a time when it was thought that either the brain would shut down or one would go insane if external stimuli were eliminated. He created methods for implanting electrodes in mammal brains and was planning to do it to himself. He was one of the first to make serious use of computers in bioscience research and created the hardware and software to make the first attempts to communicate with dolphins. He self experimented with dangerous physiological investigations in high altitude medicine for the military during WW2, took LSD with dolphins and movie stars, submitted himself to the rigors of various forms of yoga and of Arica training, and taught classes at Esalen. He was a computer pioneer who forsaw the rapid advances in A.I. and it's inevitable clash with humans. He was the first one to investigate the bizarre psychedelic ketamine (" vitamin K "), and his results (published in the two last chapters of his book `The Scientist`) are still the best data on the dose/effect relation of any psychedelic on one person. It cured his lifelong daily migraine headaches (see http://www.conspiracyarchive.com/UFOs/Gorightly.htm). And all this happened before most of us were born! He had courage, honesty and integrity that is rare anywhere and almost nonexistent in science. His goal was to find the ultimate truth about everything and he went about as far as anyone ever has. He had little patience with the stupid and hypocritical games one has to play to fit into monkey society. Of course the reaction of the establishment was predictable. He left the NIMH and was never given any government or academic support for the last 35 years of his life. His paper and comments at a conference on sensory deprivation were removed from the published version. He was not invited to government sponsored symposia on dolphins (he had refused to help develop them as weapons), though he clearly knew more about them than anyone in the world. He liked to live and work on the edge and few could keep up with him, as his books make clear. If you have read some of his other books it will be much easier going. He was a pioneer in consciousness research and pushed the boundaries of our understanding of who we are and what we might become. Among other things he catalogs the various states reached by drugs, meditation, and isolation, tries to determine their significance, and suggests how to use them. I very briefly review and comment on his life and work. -/- Those interested in all my writings in their most recent versions may download from this site my e-book ‘Philosophy, Human Nature and the Collapse of Civilization Michael Starks (2016)- Articles and Reviews 2006-2016’ by Michael Starks First Ed. 662p (2016). -/- All of my papers and books have now been published in revised versions both in ebooks and in printed books. -/- Talking Monkeys: Philosophy, Psychology, Science, Religion and Politics on a Doomed Planet - Articles and Reviews 2006-2017 (2017) https://www.amazon.com/dp/B071HVC7YP. -/- The Logical Structure of Philosophy, Psychology, Mind and Language in Ludwig Wittgenstein and John Searle--Articles and Reviews 2006-2016 (2017) https://www.amazon.com/dp/B071P1RP1B. -/- Suicidal Utopian Delusions in the 21st century: Philosophy, Human Nature and the Collapse of Civilization - Articles and Reviews 2006-2017 (2017) https://www.amazon.com/dp/B0711R5LGX -/- . (shrink)

Abstract: This article explores the medical theories of the Dutch philosopher and physician Henricus Regius (1598-1679), who sought to provide clearer notions of medicine than the traditional theories of Jean Fernel, Daniel Sennert and Vopiscus Plempius. To achieve this, Regius overtly built upon the natural philosophy of René Descartes, in particular his theories of mechanical physiology and the corpuscular nature of matter. First, I show that Regius envisaged a novel partitioning of medicine, intended to make it independent in exposition (...) but conceptually grounded in natural philosophy. This served his overall purpose of making medicine a ‘clearer’ discipline. To this end Regius detaches the general notion of physiology as the study of the human body (which pertains to natural philosophy) from a medical physiology that concerns only health. Secondly, I show that Regius’s notions of health, disease, temperament and medicaments were the product of a Cartesian interpretation of traditional concepts, which was influenced by Santorio Santorio’s project of practicing medicine without occult elements. As a consequence, Regius’s classification of these notions is largely traditional. In conclusion, I show that Regius’s method of investigation in the area of natural philosophy consisted of a problem-solving procedure based on sensorial ideas. This approach can be traced back to Descartes, but was grounded on a purely empirical theory of knowledge, by which he rejected Descartes’s metaphysics. Regius’s order of exposition in natural philosophy and medicine, on the other hand, proceeds by definitions and divisions, and omits proofs. The reasons why Regius adopted this order were: 1) his rejection of Descartes’s metaphysical interpreta-tion of physics, and 2) his wish to emphasize the conceptual clarity and continuity of natural philosophy and medicine. (shrink)

Hermann von Helmholtz allows for not only physiological facts and psychological inferences, but also perspectival reasoning, to influence perceptual experience and knowledge gained from perception. But Helmholtz also defends a version of the view according to which there can be a kind of “perspectival truth” revealed in scientific research and investigation. Helmholtz argues that the relationships between subjective and objective, real and actual, actual and illusory, must be analyzed scientifically, within experience. There is no standpoint outside experience from which we (...) can reason, no extra-sensory knowledge of the constitution of the “ideal subject” or of the properties of “real objects.” In the tradition of psychophysics inherited by Helmholtz, we can arrive at a kind of perspectival analysis of perceptual experience, which embeds an account of that experience within the context of the history and situation of the perceiving subject. That analysis is relative to the perceiving subject, but the perspectival explanations Helmholtz constructs are not thereby relativist: in fact, for Helmholtz, the more squarely the perceiving subject is placed in a scientific, perspectival context, the more facts we are able to learn about her experience and the objects with which she interacts. (shrink)

Autism has been defined as a disorder of social cognition, interaction and communication where ritualistic, repetitive behaviors are commonly observed. But how should we understand the behavioral and cognitive differences that have been the main focus of so much autism research? Can high-level cognitive processes and behaviors be identified as the core issues people with autism face, or do these characteristics perhaps often rather reflect individual attempts to cope with underlying physiological issues? Much research presented in this volume will point (...) to the latter possibility, i.e. that people on the autism spectrum cope with issues at much lower physiological levels pertaining not only to Central Nervous Systems (CNS) function, but also to peripheral and autonomic systems (PNS, ANS) (Torres, Brincker, et al. 2013). The question that we pursue in this chapter is what might be fruitful ways of gaining objective measures of the large-scale systemic and heterogeneous effects of early atypical neurodevelopment; how to track their evolution over time and how to identify critical changes along the continuum of human development and aging. We suggest that the study of movement variability—very broadly conceived as including all minute fluctuations in bodily rhythms and their rates of change over time (coined micro-movements (Figure 1A-B) (Torres, Brincker, et al. 2013))—offers a uniquely valuable and entirely objectively quantifiable lens to better assess, understand and track not only autism but cognitive development and degeneration in general. This chapter presents the rationale firstly behind this focus on micro-movements and secondly behind the choice of specific kinds of data collection and statistical metrics as tools of analysis (Figure 1C). In brief the proposal is that the micro-movements (defined in Part I – Chapter 1), obtained using various time scales applied to different physiological data-types (Figure 1), contain information about layered influences and temporal adaptations, transformations and integrations across anatomically semi-independent subsystems that crosstalk and interact. Further, the notion of sensorimotor re-afference is used to highlight the fact that these layered micro-motions are sensed and that this sensory feedback plays a crucial role in the generation and control of movements in the first place. In other words, the measurements of various motoric and rhythmic variations provide an access point not only to the “motor systems”, but also access to much broader central and peripheral sensorimotor and regulatory systems. Lastly, we posit that this new lens can also be used to capture influences from systems of multiple entry points or collaborative control and regulation, such as those that emerge during dyadic social interactions. (shrink)

Phenomenology and physiology become commensurable through a self-organizational physiology and an "enactive" view of consciousness. Self-organizing processes appropriate and replace their own needed substrata, rather than merely being caused by interacting components. Biochemists apply this notion to the living/nonliving distinction. An enactive approach sees consciousness as actively executed by an agent rather than passively reacting to stimuli. Perception does not result from mere stimulation of brain areas by sensory impulses; unless motivated organismic purposes first anticipate and "look (...) for" emotionally relevant.stimuli, brain-sensory processing is not accompanied by perceptual consciousness. To see a soccer ball requires looking for it in the right place. The sell-organizing, emotionally motivated agent instigates this looking-for activity. (shrink)

Much of the philosophical work on perception has focused on vision. Recently, however, philosophers have begun to correct this ‘tunnel vision’ by considering other modalities. Nevertheless, relatively little has been written about the chemical senses—olfaction and gustation. The focus of this paper is olfaction. In light of new physiological and psychophysical research on olfaction, I consider whether olfactory experience is object-based. In particular, I explore the claim that “odor objects” constitute sensory individuals. It isn’t obvious—at least at the outset—whether (...) they meet the widely accepted principles of object individuation and recognition at work in the visual and auditory cases. Among the general issues I consider, then, is whether these traditional principles form necessary, or simply sufficient, conditions on object perception. As we see, at the very least, considering the object-recognition model of olfaction challenges us to look more closely at well-entrenched models of object perception. But the payoff of doing so is high. We not only learn something about a modality that philosophers have historically neglected; by asking new questions and challenging old assumptions, we also further our understanding of perception in general. (shrink)

In this paper, I argue that looking at the concept of neural function through the lens of cognition alone risks cognitive myopia: it leads neuroscientists to focus only on mechanisms with cognitive functions that process behaviorally relevant information when conceptualizing “neural function”. Cognitive myopia tempts researchers to neglect neural mechanisms with noncognitive functions which do not process behaviorally relevant information but maintain and repair neural and other systems of the body. Cognitive myopia similarly affects philosophy of neuroscience because scholars overlook (...) noncognitive functions when analyzing issues surrounding e.g., functional decomposition or the multifunctionality of neural structures. I argue that we can overcome cognitive myopia by adopting a patchwork approach that articulates cognitive and noncognitive “patches” of the concept of neural function. Cognitive patches describe mechanisms with causally specific effects on cognition and behavior which are likely operative in transforming sensory or other inputs into motor outputs. Noncognitive patches describe mechanisms that lack such specific effects; these mechanisms are enabling conditions for cognitive functions to occur. I use these distinctions to characterize two noncognitive functions at the mesoscale of neural circuits: subsistence functions like breathing are implemented by central pattern generators and are necessary to maintain the life of the organism. Infrastructural functions like gain control are implemented by canonical microcircuits and prevent neural system damage while cognitive processing occurs. By adding conceptual patches that describe these functions, a patchwork approach can overcome cognitive myopia and help us explain how the brain’s capacities as an information processing device are constrained by its ability to maintain and repair itself as a physiological apparatus. (shrink)

A recently proposed model of sensory processing suggests that perceptual experience is updated in discrete steps. We show that the data advanced to support discrete perception are in fact compatible with a continuous account of perception. Physiological and psychophysical constraints, moreover, as well as our awake-primate imaging data, imply that human neuronal networks cannot support discrete updates of perceptual content at the maximal update rates consistent with phenomenology. A more comprehensive approach to understanding the physiology of perception (and (...) experience at large) is therefore called for, and we briefly outline our take on the problem. (shrink)

Many traditional attempts to show that nonhuman animals are deserving of moral consideration have taken the form of an argument by analogy. However, arguments of this kind have had notable weaknesses and, in particular, have not been able to convince two kinds of skeptics. One of the most important weaknesses of these arguments is that they fail to provide theoretical justifications for why particular physiological similarities should be considered relevant. This paper examines recent empirical research on pain and, in particular, (...) explores the implications of the dissociation between the sensory and the affective pain pathways. It is argued that these results show that the belief that nonhuman animals experience pain in a morally relevant way is reasonable, though not certain. It is further argued that the proposal to explore the relationship between consciousness and various forms of learning challenges the aforementioned skeptics to provide more physiological details for their claims that nonhuman mammals are probably not conscious. (shrink)

Hunger is a psychological state that serves physiological energy homeostasis. I argue that it is a pure underived desire to eat and examine its role in homeostasis. After scene-setting explanations of homeostasis and desire, I argue that hunger is a close phenomenological match with underived desire. Then, I show why desire is an apt instrument for energy homeostasis. Finally, I argue that energy homeostasis is a multi-factorial future-regarding behavioural strategy. Hunger is a special purpose sensory state that serves only (...) to implement the strategy. Thus, it is a sensory desire. I conclude by reflecting on the credibility of this desire. (shrink)

The dual role of olfaction in both smelling and tasting, i.e. flavour perception, makes it an important test case for philosophical theories of sensory individuation. Indeed, the psychologist Paul Rozin claimed that olfaction is a “dual sense”, leading some scientists and philosophers to propose that we have not one, but two senses of smell: orthonasal and retronasal olfaction. In this paper I consider how best to understand Rozin’s claim, and upon what grounds one might judge there to be one (...) or two distinct olfactory modalities. I conclude that while Rozin may be right that humans have dual occurrences of an olfactory ‘sense’, the concept of a sense-modality, and hence the ‘sense’ of smell, is ambiguous between two different notions: a physiological sensory channel and an experiential modality, along the lines suggested by J. J. Gibson. Furthermore, recognising that these are complementary rather than competing conceptions of a sense-modality enables the formulation of a powerful ‘dual-concept’ framework for posing and addressing questions concerning the complex architecture of human multisensory experience. (shrink)

This paper aims to outline the foundations for an ethics of digital touch. Digital touch refers to hardware and software technologies, often collectively referred to as ‘haptics’, that provide somatic sensations including touch and kinaesthesis, either as a stand-alone interface to users, or as part of a wider immersive experience. Digital touch has particular promise in application areas such as communication, affective computing, medicine, and education. However, as with all emerging technologies, potential value needs to be considered against potential risk. (...) We therefore identify some areas where digital touch raises ethical concerns, and we identify why these concerns arise, based on the distinctive physiological and functional properties of the human somatosensory system. Most scientific research in digital touch has focused on user interaction with external objects (active touch). However, the most pressing ethical concerns with digital touch technologies arise when users are being passively touched. Our analysis identifies several important questions about control, transparency, and epistemic procedure in digital touch scenarios. First, human somatosensation is “always on”, and many digital touch technologies take advantage of this (e.g., alerting systems). As a result, digital touch technologies can undermine individuals’ sensory autonomy (i.e., the right to choose what sensations one experiences). Second, users may reasonably want to know who or what is touching them, and for what purpose. Consent for digital touch will therefore need to be carefully and transparently transacted. Third, because touch gives us a special, direct experience of interacting with our physical environment, digital touch technologies that manipulate this interaction could potentially provide a major epistemic challenge, by changing a user’s basic understanding of reality and their relation to it. Informed by this discussion, we conclude by suggesting a basis for an ethical design framework for digital touch systems. (shrink)

Consciousness is seen as a difficult “binding” problem. Binding, a process where different sensations evoked by an item are associated in the nervous system, can be viewed as a process similar to associative learning. Several reports that consciousness is associated with some form of memory imply that different forms of memories have a common feature contributing to consciousness. Based on a proposed synaptic mechanism capable of explaining different forms of memory, we developed a framework for consciousness. It is based on (...) the formation of semblance of sensory stimulus from (1) synaptic semblances when excitatory postsynaptic potentials arrive at functionally LINKed postsynaptic membranes, and (2) network semblances when these potentials summate to elicit action potential initiating activity in a network of neurons. It is then possible to derive a framework for consciousness as a multi-dimensional semblance. According to this framework, a continuum of semblances formed from background sensory stimuli and oscillating neuronal activities serve to maintain consciousness. Feasibility of this framework to explain various physiological and pathological states of consciousness, its subjective nature and qualia is examined. (shrink)

Consciousness is seen as a difficult “binding” problem. Binding, a process where different sensations evoked by an item are associated in the nervous system, can be viewed as a process similar to associative learning. Several reports that consciousness is associated with some form of memory imply that different forms of memories have a common feature contributing to consciousness. Based on a proposed synaptic mechanism capable of explaining different forms of memory, we developed a framework for consciousness. It is based on (...) the formation of semblance of sensory stimulus from (1) synaptic semblances when excitatory postsynaptic potentials arrive at functionally LINKed postsynaptic membranes, and (2) network semblances when these potentials summate to elicit action potential initiating activity in a network of neurons. It is then possible to derive a framework for consciousness as a multi-dimensional semblance. According to this framework, a continuum of semblances formed from background sensory stimuli and oscillating neuronal activities serve to maintain consciousness. Feasibility of this framework to explain various physiological and pathological states of consciousness, its subjective nature and qualia is examined. (shrink)

Emotion is conscious experience. It is the affective aspect of consciousness. Emotion arises from sensory stimulation and is typically accompanied by physiological and behavioral changes in the body. Hence an emotion is a complex reaction pattern consisting of three components: a physiological component, a behavioral component, and an experiential (conscious) component. The reactions making up an emotion determine what the emotion will be recognized as. Three processes are involved in generating an emotion: (1) identification of the emotional significance of (...) a sensory stimulus, (2) production of an affective state (emotion), and (3) regulation of the affective state. Two opposing systems in the brain (the reward and punishment systems) establish an affective value or valence (stimulus-reinforcement association) for sensory stimulation. This is process (1), the first step in the generation of an emotion. Development of stimulus-reinforcement associations (affective valence) serves as the basis for emotion expression (process 2), conditioned emotion learning acquisition and expression, memory consolidation, reinforcement-expectations, decision-making, coping responses, and social behavior. The amygdala is critical for the representation of stimulus-reinforcement associations (both reward and punishment-based) for these functions. Three distinct and separate architectural and functional areas of the prefrontal cortex (dorsolateral prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex) are involved in the regulation of emotion (process 3). The regulation of emotion by the prefrontal cortex consists of a positive feedback interaction between the prefrontal cortex and the inferior parietal cortex resulting in the nonlinear emergence of emotion. This positive feedback and nonlinear emergence represents a type of working memory (focal attention) by which perception is reorganized and rerepresented, becoming explicit, functional, and conscious. The explicit emotion states arising may be involved in the production of voluntary new or novel intentional (adaptive) behavior, especially social behavior. (shrink)

FISIOLOGIA DO PARTO E DA LACTAÇÃO ANIMAL -/- ANIMAL REPRODUCTION: PHISIOLOGY OF PARTURITION AND ANIMAL LACTATION -/- Emanuel Isaque Cordeiro da Silva Departamento de Zootecnia da UFRPE WhatsApp: (82)98143-8399 -/- 1. INTRODUÇÃO O sucesso biológico do processo de reprodução culmina com a sobrevivência das crias. Durante a gestação, o feto desenvolve-se no útero materno protegido das influências externas, e obtendo os nutrientes e o oxigênio através da mãe. O parto é o processo biológico que marca o fim da gestação e (...) o início da vida extrauterina do animal. Para garantir a sobrevivência do recém-nascido o parto deve ser um processo controlado para que se inicie unicamente quando o feto tiver alcançado desenvolvimento suficiente que lhe permita enfrentar a vida extrauterina. Após o nascimento, a secreção de leite pela glândula mamária proporciona ao neonato tanto os nutrientes necessários para seu desenvolvimento como as defesas (imunoglobulinas) que lhe protegerão contra as possíveis infecções durante as primeiras fases de sua vida. Parto e lactação constituem a última etapa de um ciclo reprodutivo completo nas fêmeas dos animais domésticos, estando ambos os processos regulados e sincronizados por complexas mudanças hormonais na mãe. Estas mudanças são, em última análise, provocadas e governadas pelo próprio feto ou recém-nascido, o qual acomoda as respostas maternas às suas necessidades garantindo a sua sobrevivência. 2. O PARTO O parto é definido como o processo fisiológico pelo qual ocorre a expulsão de um ou mais fetos maduros, bem como das membranas fetais existentes no útero materno. Este processo é desencadeado por uma interação complexa entre as hormonas maternas (fatores maternos) e fetais (fatores fetais). Para que se realize a expulsão do feto é necessário que o útero deixe de ser um órgão quiescente, essencial para a manutenção da gestação, para ser um órgão contrátil. Ao mesmo tempo, o cérvix ou colo uterino, que durante a gestação permanece firmemente fechado para impedir a expulsão prematura do feto e evitar a entrada de agentes infecciosos, relaxa e dilata para facilitar a passagem do feto na hora do parto. Esta modificação na atividade do útero e do colo uterino, ocorrem como consequência das mudanças hormonais que o organismo materno experimenta à medida que a data do parto se aproxima. 2.1 Fatores maternos A gestação dos animais domésticos ocorre com elevada concentração de progesterona que, dependendo da espécie animal, é secretada seja pelo corpo lúteo do ovário (vaca, porca e cabra) ou pela placenta (ovelha e égua). A progesterona desempenha um papel fundamental durante a gestação, inibindo as contrações da musculatura lisa do útero (miométrio), permitindo assim a acomodação do feto durante o seu crescimento. Os estrogênios, estimulantes da atividade contrátil do miométrio, mantêm-se a baixas concentrações durante a maior parte da gestação. À medida que se aproxima o momento do parto, os níveis destes hormônios esteroides modificam-se, produzindo-se a diminuição nos níveis circulantes da progesterona ao mesmo tempo que se incrementam os valores sanguíneos dos estrogênios (figura 1). A redução dos níveis de progesterona suprime a sua ação inibitória sobre a atividade contrátil do miométrio, permitindo que se manifestem os efeitos estimulantes dos estrogênios sobre este órgão. A concentração de estrogênios começa a aumentar geralmente no final da gestação, atingindo os seus valores máximos no momento do parto (figura 1). O aumento da concentração de estrogênios favorece a atividade contrátil espontânea do útero ao: a) estimular a síntese de proteínas contráteis; b) aumentar, sob medida, a sensibilidade do miométrio uterino à ação estimulante das prostaglandinas; c) induzir a formação de receptores de oxitocina no útero. -/- Figura 1. Níveis de progesterona e estrógenos durante a gestação e parto das espécies ovina, caprina, suína e bovina. Fonte: HAFEZ, 2013. Os estrogênios estimulam a síntese e secreção de prostaglandina (PGF2a), que constitui o elemento essencial para o início do parto devido aos efeitos que esta substância provoca. Assim, nas fêmeas, cujos níveis de progesterona gestacional dependem da presença do corpo lúteo, a secreção de PGF, origina a regressão deste (luteólise), com a consequente diminuição da progesterona a níveis basais. Além disso, a PGF2a origina contrações de crescente intensidade no útero sensibilizado pela ação dos estrogênios. Esta ação contrátil da PGF2a deve-se a um aumento da concentração de cálcio intracelular das fibras musculares uterinas. A PGF2a também está envolvida no relaxamento do colo do útero, inibindo a formação de colágeno cervical ao mesmo tempo que estimula a síntese de enzimas (colagenase) que degradam a matriz de colágeno formado no início da gestação. A dilatação do colo do útero está também associada à pressão que o feto exerce sobre o mesmo e, no caso da porca, a relaxina pode também estar envolvida. Esta hormona é também de grande importância para a preparação do parto em todas as espécies animais, uma vez que é responsável pelo relaxamento dos ligamentos e músculos que rodeiam o canal pélvico para favorecer a separação da sínfise púbica durante a expulsão do feto. Nos grandes animais (vaca, égua) as mudanças que ocorrem nos tecidos e ligamentos pélvicos são muito evidentes e constituem um sintoma de parto iminente. O início do parto, ou primeira fase do parto, caracteriza-se pelo aumento das contrações uterinas provocadas pela PGF2a coincidindo com a dilatação do colo uterino para permitir a passagem do feto para o canal do parto, momento em que começa a segunda fase do parto. A distensão vaginal que produz-se para a passagem do feto pelo canal do parto origina um estímulo nervoso que viaja através da medula espinal para o hipotálamo, onde se encontram os neurônios responsáveis pela síntese de oxitocina. As terminações nervosas destes neurónios são projetadas para o lobo posterior da hipófise (neurohipófise), onde a oxitocina é secretada para ser, posteriormente , transportada pela circulação sanguínea. Este reflexo neuroendócrino chamado reflexo de Ferguson determina a secreção súbita de oxitocina, provocando o aumento tanto na intensidade como na frequência das contrações uterinas necessárias para a expulsão final do feto. O papel da oxitocina é ativar a conclusão do processo de expulsão, uma vez que esta hormona não está envolvida no início do parto. A alteração mais significativa entre a gestação e o parto é a alteração na atividade contrátil do miométrio uterino. Esta mudança é devido às alterações hormonais que ocorrem na mãe quando a gestação chegou a fim. No entanto, para que estes mecanismos maternos sejam acionados, é necessário que o feto indique de alguma forma à mãe o seu estado de desenvolvimento, de modo que o nascimento realize-se quando o feto estiver preparado para enfrentar a vida extrauterina. 2.2 Fatores fetais A destruição experimental da hipófise e/ou das glândulas adrenais do feto origina o prolongamento da gestação nos animais domésticos. Pelo contrário, a administração exógena de cortisol (corticosteroides adrenais), ou do seu precursor hipofisário (ACTH), à circulação fetal provoca, em poucas horas, o início do parto. Estes fatos evidenciam a importância do eixo hipófise-adrenal do feto para desencadear o início do parto (figura 2). Figura 2. Mecanismos fetais que controlam o parto em ovelhas. Fonte: LIGGINS et al, 1972. No final da gestação, o feto maduro apresenta um aumento da concentração de corticosteroides plasmáticos devido ao efeito estimulante da hormona adrenocorticotróide (ACVH) secretada pela hipófise fetal sobre as glândulas adrenais do feto. Os corticosteroides fetais por sua vez estimulam as enzimas placentárias para transformar a progesterona em estrogênio. O resultado final é a diminuição dos níveis de progesterona ao mesmo tempo que se eleva a concentração de estrogênios que, por sua vez, estimulam a libertação de PGF2a responsável pelas contrações uterinas. Este raciocínio explica algumas doenças caracterizadas por gestação prolongada em ovelhas, como ocorre na África do Sul, onde estes animais são obrigados, durante as épocas de seca, a ingerir as folhas de um arbusto chamado Salsola tuberculate. O prolongamento da gestação ocorre quando estas folhas são ingeridas durante o último terço da gestação cujos efeitos estão relacionados com a supressão do eixo hipotálamo-hipófise, com o qual as adrenais não recebem o estímulo necessário (ACTH) para a síntese e liberação de corticoides. O efeito contrário é observado nas cabras da raça Angorá, nas quais se produzem, com relativa frequência, partos prematuros que podem estar relacionados com um desenvolvimento precoce das glândulas adrenais. Isto significa que, nos animais domésticos, o feto determina a data do parto. O sinal hormonal que indica à mãe o grau de maturidade do feto é o desenvolvimento do eixo hipotálamo-hipófise-adrenal que origina o aumento na secreção de corticoides fetais que são os responsáveis por desencadear as alterações hormonais no organismo materno necessárias para iniciar o parto. A figura 2 mostra como a remoção da hipófise e as adrenais do feto prolongam a gestação, enquanto a administração exógena de ACTH ou corticoides (cortisol) ao feto originam um parto prematuro. O momento em que ocorre o aumento da concentração plasmática de corticoides no feto varia de acordo com a espécie: de 25 a 30 dias antes do parto na vaca, de 7 a 10 dias na porca e de 2 a 3 dias na ovelha. 2.3 Desenvolvimento e fases do parto O parto inicia-se com o início das contrações peristálticas e regulares do miométrio uterino ao mesmo tempo que o colo do útero se dilata progressivamente. Nas fêmeas que gestam um único feto (monotecas), as contrações começam na extremidade anterior do córneo uterino, enquanto que nas espécies que gestam vários fetos (politocas) as contrações começam pela extremidade cervical para começar a expulsar o feto que se encontra mais próximo do cérvix. Durante o parto são reconhecidas três fases: 1. Fase preparatória - Na qual as contrações uterinas estimulam a rotação do feto (fêmeas monotecas) para adotar a posição dorsal (extremidades anteriores e cabeça forçadas contra o cérvix) que lhe permite oferecer a menor resistência para sua expulsão. A PGF2a provoca as contrações miometriais e a dilatação do cérvix, deslocando o feto contra e através desta estrutura. 2. Fase de expulsão - A passagem do feto através do colo uterino e da vagina causam a completa dilatação destas estruturas, originando a secreção de oxitocina (reflexo de Ferguson), que provoca contrações de maior frequência e intensidade. Por sua vez, estas contrações uterinas são reforçadas pela pressão e contração dos músculos abdominais, chegando estes últimos a ser a força principal (forças de expulsão) envolvida no processo de expulsão do feto. O cordão umbilical rompe-se bem ao levantar-se a mãe ou pelos movimentos do recém-nascido. 3. Fase de expulsão da placenta - Após o parto, as contrações rítmicas do útero continuam a facilitar a expulsão da(s) placenta(s). O tempo necessário para este processo varia de acordo com a espécie animal. Este processo é rápido na égua, já que a separação do corion (membrana fetal) de sua inserção uterina ocorre durante a expulsão do feto, com o qual o parto deve ser concluído rapidamente ou, caso contrário, o potro se asfixiaria. Nos ruminantes, a expulsão da placenta cotiledonaria é um processo mais lento que exige a separação dos cotilédones (membrana fetal) das carúnculas do útero. Por conseguinte, a troca de nutrientes e oxigênio entre a mãe e o feto continua até que este tenha sido totalmente expelido, devido ao cordão umbilical destes animais ser bastante longo. Nas fêmeas politocas, como a porca, geralmente as placentas de vários leitões são expulsadas no final, quando os leitões já foram expelidos, se bem que o último leitão poderá ser expelido durante a expulsão da massa placentária. 3. LACTAÇÃO A lactação constitui o processo que define os mamíferos como classe biológica. O desenvolvimento pós-natal dos mamíferos vai depender, em grande medida, dos nutrientes e defesas fornecidos pela mãe através da secreção de leite (imunoglobulinas). Assim, uma vez concluído o desenvolvimento gestacional do feto, a glândula mamária irá substituir, de certa forma, a função nutritiva e protetora da placenta durante a gestação. 3.1 Anatomia funcional da glândula mamária A estrutura funcional da glândula mamária é muito semelhante em todos os mamíferos, embora o tamanho, forma e número de glândulas varia dependendo da espécie animal. As glândulas mamárias desenvolvem-se como estruturas pares cujo número varia de um par (égua, cabra e ovelha), dois pares (vaca) até sete ou nove (porca). A localização das glândulas também difere sendo inguinal em vaca, égua, cabra e ovelha, enquanto que na porca, cadela e gata se estendem por todo o comprimento do tórax e abdômen. Nos animais domésticos em geral as glândulas mamárias recebem o nome de úberes. Tomando como modelo a vaca, a glândula mamária se organiza em duas estruturas: o estroma, formado por tecido conjuntivo procedente dos ligamentos suspensório medial, localizado entre os dois pares de glândulas, dando suporte à segunda estrutura que é o tecido secretor. Este é formado por acúmulos de células secretoras formando estruturas ocas chamadas alvéolos, que são as unidades fundamentais secretoras de leite. Os alvéolos estão circulados internamente por células epiteliais (secretoras) e rodeados externamente por células mioepiteliais contráteis, cuja contração origina a ejeção do leite (figura 3). O agrupamento de vários alvéolos adjacentes formam um lobo secretor. Figura 3. Diagrama de um agregado de alvéolos na glândula mamária de uma cabra. Fonte: COWIE et al, 1980. Os lobos expelem a secreção através de ductos que, por sua vez, drenam os ductos galactóforas (ductos lácteos) de maior diâmetro, para desembocar em áreas especializadas em armazenar o leite chamadas cisternas (vaca, cabra). Finalmente, a cisterna abre-se para o exterior através do canal papilar da teta. A presença do músculo liso na teta permite-lhe agir como esfíncter para impedir que o leite seja expelido passivamente do interior da glândula. O mamilo/teta é provido de numerosos receptores sensitivos cuja excitação durante a ordenha ou amamentação vai desencadear estímulos nervosos de grande importância para a manutenção da lactação. 3.2 Desenvolvimento da glândula mamária (mamogênese) A glândula mamária difere das demais glândulas do organismo no escasso desenvolvimento que apresenta no nascimento da fêmea, o qual não se inicia até que esta não atinja a puberdade. O início da atividade cíclica do ovário (puberdade) dá origem à síntese de estrogênios (fase folicular do ciclo estral) e progesterona (fase lútea). Os estrogênios originam o alongamento e ramificação dos ductos e a formação de pequenas massas esféricas de células (os futuros alvéolos). Embora este desenvolvimento seja dependente do estrogênio, é também necessária a ação sinérgica da prolactina, hormona do crescimento (GH) e corticoides adrenais, como demonstrado pelos estudos realizados em ratos aos quais foi removida a hipófise, glândulas suprarrenais e ovários (figura 4). A função da progesterona no desenvolvimento da glândula mamária é estimular o crescimento do lobo-alveolar, mas como no caso anterior também requer a ação conjunta dos hormônios acima mencionados. Figura 4. Hormonas relacionadas com o crescimento da glândula mamária e início da secreção de leite na rata hipofisectomizada-adrenoectomizada-ovariectomizada. Fonte: COWIE, 1980. O desenvolvimento da glândula, durante cada ciclo estral, vai depender da duração da fase folicular (níveis elevados de estrogênio), já que nas restantes fases do ciclo, quando os níveis de estrogênio são baixos, os ductos sofrem uma ligeira regressão. Nas espécies com ciclos curtos (rata), em que a fase folicular do ciclo é predominante, enquanto a fase lútea é quase inexistente, verifica-se um grande desenvolvimento dos ductos; enquanto que aquelas que apresentam um corpo lúteo funcional de longa duração (cadela e primatas), além do crescimento dos ductos, mostram um grande desenvolvimento lóbulo-alveolar semelhante ao que ocorre na gestação. É durante a gestação que o sistema alveolar sofre uma hipertrofia considerável, resultando em lobos proeminentes e no desenvolvimento da luz interna dos alvéolos, fato que é evidente na maioria dos animais domésticos por volta da metade do período gestacional. Em algumas espécies, as células que circundam interiormente os alvéolos contêm produtos secretores, indicando que a glândula mamária já está preparada para a fase da lactação. O desenvolvimento glandular durante a gestação deve-se ao efeito conjunto da progesterona e dos estrogênios com as hormonas hipofisárias acima mencionadas: prolactina, hormona do crescimento (GH) e adrenocorticotropina (ACTH). A proporção entre estrogênios e progesterona varia de acordo com a espécie, mas geralmente é necessária uma maior concentração de progesterona (proveniente do corpo lúteo ou da placenta). Quanto às hormonas hipofisárias, a prolactina desempenha um papel fundamental na diferenciação da glândula mamária (mesmo a baixas concentrações) ao estimular o desenvolvimento do epitélio secretor dos alvéolos. A GH favorece o crescimento dos ductos e a ACTH estimula a secreção de corticoides nas adrenais que, por sua vez, favorecem de forma generalizada o crescimento das glândulas. 3.3 Secreção da glândula mamária (lactogênese) A lactogênese, ou o processo pelo qual se produz a síntese e secreção do leite pela glândula mamária, começa no final da gestação coincidindo com o desencadeamento do parto. O primeiro leite formado imediatamente antes ou depois do parto é denominado colostro. No entanto, a lactação não pode desenvolver- se completamente até que se inicie o processo de parto. Isto deve-se ao fato de que o processo de lactação resulta de uma interação complexa de hormonas que preparam a glândula mamária para a secreção do leite. Os requisitos hormonais mínimos para o início da lactogênese são: aumento da secreção de estrogênios, prolactina e corticoides, juntamente com a diminuição da concentração de progesterona, perfis hormonais que estão intimamente relacionados com o desencadeamento do parto. Isto deve-se ao fato de que a progesterona inibe a atividade lactogênica da prolactina bloqueando a formação dos seus receptores na glândula mamária durante a gestação impedindo, assim, a prolactina de sintetizar os componentes fundamentais do leite. Pelo contrário, o aumento da concentração de estrogênios no final da gestação (figura 1, na seção do parto) estimula a síntese, o armazenamento e a secreção hipofisária de prolactina. Assim, apesar da glândula mamária estar preparada para iniciar a secreção de leite, muito antes da data prevista para o parto, a elevada concentração de progesterona (existente durante esse período de gestação) impede a fase láctea (saída do leite pelas tetas) de ocorrer antes da expulsão do feto. Desta forma, o feto poderá beneficiar das vantagens que o fornecimento do colostro materno irá trazer para a sua sobrevivência (imunização, nutrição e favorecimento da exoneração do mecônio). O aumento da concentração de estrogênios nos dias que antecederem o parto resulta num rápido aumento das concentrações plasmáticas de prolactina e corticoides. A prolactina é a hormona lactogênica mais importante na síntese dos componentes do leite. No entanto, para que esta hormona possa exercer a sua função, é necessária a participação dos corticoides, já que os mesmos são os responsáveis pelo desenvolvimento das organelas citoplasmáticas (retículo endoplasmático rugoso e aparelho de Golgi) onde se realiza a síntese do leite. No desenvolvimento da lactogênese, para além da prolactina e dos corticoides, participam também outras hormonas como a insulina, a tiroxina e o hormônio do crescimento. A insulina estimula a proliferação de novas células epiteliais na glândula mamária, enquanto a tiroxina, embora não seja essencial para a lactação, pode influenciar no volume de leite produzido pela fêmea (alta produção leiteira). Por último, a hormona do crescimento favorece, em geral, a lactação, existindo atualmente um interesse considerável no uso desta hormona para promover a produção adicional de leite em vacas através da sua administração exógena (trabalho e projeto desenvolvido pela professora titular e médica-veterinária do IFPB Campus Sousa Marianne Christina Velaqua). 3.3.1 Síntese e secreção dos componentes do leite Os principais constituintes do leite são: proteínas (caseína, alfa-lactalbumina, albumina sérica e imunoglobulinas), açúcares (lactose), gorduras (principalmente sob a forma de triglicerídeos), vitaminas, minerais e citrato (no caso dos ruminantes). As proteínas (caseína e alfa-lactalbumina) são sintetizadas no retículo endoplasmático rugoso e posteriormente embaladas em vesículas secretoras do aparelho de Golgi para serem liberadas da célula para a luz alveolar mediante um processo de exocitose. A lactose é o principal açúcar do leite que, além disso, atua regulando a pressão osmótica do mesmo de modo que o volume de leite que a glândula mamária segrega está diretamente relacionado com a quantidade de lactose presente. A síntese da lactose ocorre no aparelho de Golgi pela condensação de glicose e galactose; esta reação é catalisada por uma enzima (lactose sintetase) presente na membrana do aparelho de Golgi que, por sua vez, é ativada pela proteína alfa-lactalbumina. Esta proteína só aparece na glândula mamária e é essencial para a síntese da lactose, o que demonstra que este açúcar é exclusivamente formado no leite. A lactose é também embalada junto com o cálcio, o fosfato e as proteínas nas vesículas secretoras para ser expulsada ao lúmen alveolar por exocitose. As imunoglobulinas (anticorpos IgA) são formadas pelas células plasmáticas, derivadas dos linfócitos B do sangue, como consequência da exposição da mãe a diferentes microrganismos. Estes anticorpos passam para a glândula mamária por migração dessas células a partir dos tecidos adjacentes. Os triglicerídeos são sintetizados no citoplasma e no retículo endoplasmático liso a partir de ácidos graxos provenientes da circulação sanguínea; em seguida, unem-se formando glóbulos de gordura que se dirigem até o vértice da membrana plasmática para serem finalmente expelidos para a luz do alvéolo, rodeados pela membrana, formando assim uma dispersão de glóbulos de gordura (figura 5). Figura 5. Estrutura de três células alveolares durante a síntese do leite. Fonte: COWIE, 1980. Do ponto de vista quantitativo, a caseína e os triglicerídeos constituem as proteínas e as fontes de energia, respectivamente, mais importantes do leite. Por último, o citrato é um intermediário do metabolismo da glicose que ocorre em grande concentração no leite dos ruminantes. Este composto é também englobado no interior das vesículas secretoras, junto com os outros compostos, para sua expulsão à luz alveolar. A composição do leite varia dependendo da espécie animal, e difere também até entre a mesma espécie. Estas variações estão relacionadas com a raça, idade, estágio de lactação e estado nutricional do animal. O teor de gordura no leite de ovelhas, porcas, cadelas e gatas varia entre 7 e 10%. No gado leiteiro estes valores variam de 3,5 a 5,5%, dependendo da raça. Em relação às cabras, os valores de gordura são muito semelhantes aos das vacas, enquanto o leite das éguas é o que tem menor teor de gordura (tabela 1). Espécie Gordura Proteína Lactosa Cinzas/Cálcio Gata 7,1 10,1 4,2 0,5 Vaca holandesa 3,5 3,1 4,9 0,7 Cadela 9,5 9,3 3,1 1,2 Cabra 3,5 3,1 4,6 0,8 Égua 1,6 2,4 6,1 0,5 Tabela 1. Composição do leite em várias espécies (%). Fonte: JACOBISON, 1984. 3.4 Manutenção da lactação (galactopoiese) A capacidade da glândula mamária de secretar um grande volume de leite começa em/ou imediatamente antes do parto, para aumentar no período pós-parto durante um tempo variável e, posteriormente, diminuir de forma gradual. Em geral, existe um paralelismo entre a atividade secretora da glândula e a procura de leite por parte do lactente. Isto deve-se ao fato de sucção pelo lactente, ou a extração por ordenha, que constituem o fator fundamental para a manutenção da lactação. A sucção estimula a lactação de duas formas: a) reduzindo os efeitos inibitórios da pressão intramamária produzida pela acumulação de leite, e b) estimulando intensamente a secreção de hormonas necessárias para manter a síntese e secreção de leite nos alvéolos. As hormonas que desempenham um papel fundamental na manutenção da lactação são: I) a prolactina, que é responsável pela estimulação da síntese e secreção de leite nas células epiteliais nos alvéolos, e 2) a oxitocina, que provoca a contração das células musculares que circundam externamente os alvéolos e os ductos (células mioepiteliais). A libertação de ambos os hormônios ocorre como resultado de um reflexo neuroendócrino originado pela estimulação do mamilo. 3.4.1 Secreção reflexa de prolactina A secreção de prolactina é regulada por dois fatores hipotalâmicos: a dopamina, que inibe a secreção de prolactina e um fator cuja identidade não está bem definida, conhecido como fator liberador de prolactina (PRF)que estimula a liberação deste hormônio. O estímulo sensorial originado como sequência da estimulação do mamilo, pela sucção do lactente, é transportado através da medula espinhal para o hipotálamo, onde atua na inibição da dopamina ou estimulando a secreção do PRF para desencadear a secreção de prolactina da adenohipófise para a circulação sanguínea (figura 6). Figura 6. Reflexos neuroendócrinos secretores de prolactina e oxitocina. Fonte: HAFEZ, 2000. A prolactina estimula a secreção dos componentes do leite para a luz dos alvéolos, afim de repor o volume de leite extraído durante a última ordenha ou sucção. Ao mesmo tempo, a prolactina induz a síntese das proteínas, incluindo a alfa-lactalbumina para estimular novamente a síntese da lactosa, bem como as enzimas necessárias para a produção dos triglicerídeos. Desta forma, a secreção de prolactina originada pelo lactente durante o aleitamento proporciona um mecanismo simples para combinar o volume de produção de leite com as necessidades do lactente. A quantidade de prolactina liberada durante cada período de sucção depende do número de crias, da duração do estímulo e dos intervalos de tempo decorridos entre os períodos de sucção (ou ordenha). No caso das vacas leiteiras, as ordenhas são geralmente realizadas de doze em doze horas, intervalo de tempo suficiente para manter a lactogênese. Os valores plasmáticos de prolactina aumentam imediatamente após o início da ordenha, mas os valores mais elevados são obtidos cerca de meia hora após o início do estímulo (ordenha ou sucção). A secreção de prolactina e a produção de leite são influenciadas de alguma forma pelo fotoperíodo, uma vez que, em alguns animais se comprovou como o aumento do número de horas de exposição à luz dá origem a um aumento da concentração de prolactina circulante, bem como uma maior produção de leite (entre 6 e 10%) (trabalho e projeto elaborado pelos estudantes do curso técnico em agropecuária e da graduação em Medicina Veterinária do IFPB Campus Sousa sob a coordenação e orientação da profa. Me. Esp. Marianne C. Velaqua). 3.4.2 Reflexo da ejeção do leite A sucção do mamilo pelo lactente estimula os receptores sensoriais presentes nesta estrutura, originando a geração de impulsos nervosos que são transmitidos pelas vias nervosas ascendentes da medula espinhal para os corpos celulares produtores de oxitocina no hipotálamo. O estímulo desencadeia a síntese e liberação de um bolo de oxitocina através das terminações nervosas dos núcleos hipotalâmicos para a neurohipófise, da qual é transmitida, através do sangue, para a glândula mamária, provocando a contração das células mioepiteliais que rodeiam os alvéolos (figura 6). Além da estimulação direta do mamilo provocada pela sucção, qualquer estímulo relacionado à ordenha é capaz de gerar o reflexo da ejeção, por exemplo: os estímulos sensoriais auditivos (ruído dos cubos na hora da ordenha), visuais (ambiente da sala de ordenha), táteis (lavagem manual dos mamilos antes da ordenha) e os estímulos olfatórios que se produzem em torno do animal. O desencadeamento do reflexo de ejeção pelos estímulos sensoriais, que não estão diretamente relacionados com a sucção ou ordenha, indica a possível participação de centros superiores do sistema nervoso central para controlar a secreção de oxitocina. Esta teoria é baseada em que os estímulos relacionados com situações de estresse em animais de estimação (medo, ansiedade, frio, etc.) inibem a ejeção do leite. A contração das células mioepiteliais gera um aumento da pressão intra-alveolar mamária, provocando o deslocamento do leite para os ductos maiores da glândula. Este efeito é popularmente conhecido como diminuição do leite e constitui um mecanismo fisiológico muito eficaz para controlar a expulsão do leite para o mamilo, assegurando que a ejeção do leite se realize unicamente quando o lactente o demanda. O efeito estimulante da oxitocina é de grande importância já que a maior parte do leite se encontra nos alvéolos e nos ductos, com o qual, a ausência deste hormônio provocaria um lento movimento do leite para a cisterna do úbere e, portanto, uma menor quantidade de leite. Assim, quando os alvéolos e ductos menores são contraídos, ocorre o relaxamento dos ductos principais, bem como da cisterna (ruminantes) e do mamilo, o que dá origem a um aumento destas estruturas para alojar o volume de leite expelido. Como resultado da volumosa ejeção do leite dos alvéolos e ductos menores, ocorre um aumento da pressão intramamária de modo que o lactente terá que vencer a resistência do esfíncter do mamilo para poder extrair o leite. A produção de leite pela glândula mamária diminui gradualmente à medida que os intervalos de tempo entre os dois períodos de amamentação do lactente diminuem e os estímulos necessários para manter as concentrações de prolactina e oxitocina na circulação sanguínea. A diminuição ou cessação da secreção de leite, geralmente coincide com a mudança na alimentação das crias (desmame) para passar à dieta característica da espécie. 3.5 Colostro O colostro é o primeiro leite que se forma na glândula mamária coincidindo com o parto. A ingestão de colostro por recém-nascidos é de grande importância para a sua sobrevivência, não só pelo seu elevado valor nutritivo, mas também pelo seu teor em imunoglobulinas (IgA) que lhe confere a imunização passiva necessária para o proteger contra patologias. Em algumas espécies (homem, coelho e cobaia) grande parte dos anticorpos passam para a circulação do feto através da placenta durante a gestação. Nos animais domésticos (vaca, égua, ovelha, cabra, porco) as características da placenta (número de camadas entre a circulação materna e fetal) não permitem a passagem destas proteínas. Como resultado, a imunização das crias nestas espécies animais vai depender da transferência das imunoglobulinas através do colostro. O epitélio intestinal dos recém-nascidos permite a passagem destas imunoglobulinas durante as primeiras 24 a 48 horas de vida. Passado este tempo, o epitélio torna-se impermeável à passagem dos anticorpos, fato que põe em evidência a importância que tem para os animais recém-nascidos e desprovidos de defesas a ingestão do colostro durante os primeiros dias. A composição do colostro caracteriza-se (em relação ao leite normal) por um teor mais elevado de proteínas, vitaminas, minerais e uma menor concentração de lactose. A composição do colostro muda gradualmente durante os primeiros três dias após o parto para se transformar em leite normal. 4. RESUMO E PRIMEIRAS CONCLUSÕES O parto, ou processo fisiológico pelo qual se expulsa o feto, é o resultado da maturação sequencial de um sistema de comunicação hormonal. A sequência inicia-se no sistema nervoso central do feto de onde os sinais são transmitidos e amplificados, através da hipófise, para as glândulas adrenais fetais, as quais respondem ao estímulo mediante a secreção de cortisol. O aumento da concentração de cortisol por parte do feto indica que este conseguiu o desenvolvimento necessário para enfrentar a vida extrauterina e, portanto, é hora de interromper a gestação. O cortisol atua sobre a placenta para aumentar a secreção de estrogênios que, por sua vez, estimulam a síntese e a liberação de prostaglandinas. O resultado é a diminuição da progesterona, que é a hormona encarregada de manter a gestação ao inibir as contrações espontâneas do útero, impedindo assim a expulsão prematura do feto. O útero, sob os efeitos da prostaglandina, começa a contrair-se ao mesmo tempo que o colo uterino amolece e dilata progressivamente (fase preparatória do parto). A passagem do feto ao canal do parto origina a secreção reflexa de oxitocina (fase de expulsão), causando contrações de maior frequência e intensidade que culminam com a expulsão do feto. Finalmente, as contrações uterinas continuam durante algum tempo até que finalmente é expulsa a placenta (fase de expulsão da placenta). O desenvolvimento da glândula mamária durante a gestação e a subsequente capacidade desta estrutura para secretar leite, coincidindo com o parto, oferece aos animais pertencentes à classe biológica dos mamíferos a vantagem de alimentar as suas crias para assegurar a sua sobrevivência durante as primeiras fases do seu desenvolvimento e, portanto, a continuidade da espécie. A lactação constitui um dos processos fisiológicos mais complexos em consequência do grande número de hormonas que, segregadas de forma coordenada, controlam as diferentes fases pelo que atravessa este processo: I) mamogênese ou desenvolvimento dos dutos e estruturas lóbulo-alveolares durante a gestação; 2) lactogênese ou síntese láctea por células epiteliais e sua secreção para a luz alveolar coincidindo com o parto, e 3) galactopoiese ou manutenção da síntese e secreção do leite como consequência da sua extração da glândula mamária seja pela sucção da cria ou pela ordenha. -/- Emanuel Isaque Cordeiro da Silva – Departamento de Zootecnia da UFRPE. Recife, 2020. -/- REFERÊNCIAS BIBLIOGRÁFICAS -/- BEIGHLE, D. E. The effect of gestation and lactation on bone calcium, phosphorus and magnesium in dairy cows. Journal of the South African Veterinary Association, v. 70, n. 4, p. 142-146, 1999. BRACKELL, B. G.; JR SEIDEL, G. E.; SEIDEL, S. Avances en zootecnia nuevas técnicas de reproducción animal. Zaragoza: Acribia, 1988. COLE, H. H.; CUPPS, P. T. Reproduction in domestic animals. 1ª ed. Londres: Academic Press, 1977. COWIE, Alfred T.; FORSYTH, Isabel A.; HART, Ian C. Lactation. In: Hormonal control of lactation. Springer, Berlin, Heidelberg, 1980. p. 146-229. CUNNINGHAM, James G. Fisiología veterinaria. São Paulo: Elsevier, 2003. DERIVAUX, Jules; BARNABÉ, Renato Campanarut. Reprodução dos animais domésticos. Zaragoza: Acribia, 1980. DA SILVA, Emanuel Isaque Cordeiro. Definição de Conceitos Básicos na Reprodução Animal: Fertilidade, Fecundidade e Prolificidade-Suínos. Philarchive. Disponível em: -----. Acesso em: Fevereiro de 2020. DA SILVA, Emanuel Isaque Cordeiro. Características Gerais dos Bovinos/General Characteristics of Cattle Bovine. Philarchive. Disponível em: -----. Acesso em: Fevereiro de 2020. DA SILVA, Emanuel Isaque Cordeiro. Reprodução Animal: Fecundação e Gestação. Disponível em: Acervo IFPE. Acesso em: Março de 2020. FERNÁNDEZ ABELLA, Daniel Héctor. Principios de fisiología reproductiva ovina. Montevidéu: Hemisferio Sur1993. GONZÁLEZ, Félix HD. Introdução a endocrinologia reprodutiva veterinária. Porto Alegre: UFRGS, v. 83, 2002. HAFEZ, E. S. E.; HAFEZ, B. Reprodução animal. São Paulo: Manole, 2004. HAFEZ, Elsayed Saad Eldin; HAFEZ, B. (Ed.). Reproduction in farm animals. Nova Jersey: John Wiley & Sons, 2013. HUNTER, R. H. F. Reproducción de los animales de granja. Zaragoza: Acribia, 1987. HUNTER, Ronald Henry Fraser et al. Physiology and technology of reproduction in female domestic animals. Londres: Academic Press, 1980. ILLERA, M. Endocrinología Veterinaria y Fisiología de la Reproducción. Zaragoza: Fareso, 1994. JACOBSON, N. L.; MCGILLIARD, A. D. The mammary gland and lactation. Duke’s Physiology of Domestic Animals. 10th edition. Comstock Publishing Associates, Cornell University Press, Ithaca, New York, USA, p. 863-880, 1984. JAINUDEEN, M. R.; HAFEZ, E. S. E. Gestação, fisiologia pré-natal e parto. Revista Brasileira de Reprodução animal, v. 7, p. 141-142, 2004. LIGGINS, G. C. et al. physiological roles of progesterone, oestradiol-17beta and prostaglandin F2alpha in the control of ovine parturition. J Reprod and Fert Suppl, 1972. PÉREZ PÉREZ, F.; PÉREZ GUTIÉRREZ, F. Reproducción animal, inseminación animal y transplante de embriones. Barcelona: Cientifico-medica, 1985. ROBERTS, Stephen J. Obstetricia veterinaria y patología de la reproducción. Montevidéu: Hemiferio Sur, 1979. SALISBURY, G. W.; VANDERMARK, N. L. Phisiology of the reproduction and artificial insemination of cattle. San Francisco : Freeman e Company, 1961, 630 p. SHILLE, V. M. Fisiologia reprodutiva e endocrinologia da fêmea e do macho. Tratado de medicina interna veterinária. São Paulo: Manole, p. 1857-68, 1992. RUTTER, Bruno; RUSSO, Angel F. Fundamentos de la fisiología de la gestación y el parto de los animales domésticos. Buenos Aires: Eudeba, 2002. UNGERFELD, Rodolfo. Reproducción en los animales domésticos. Montevidéu: Melibea, 2002. (shrink)

Consciousness is seen as a difficult “binding” problem. Binding, a process where different sensations evoked by an item are associated in the nervous system, can be viewed as a process similar to associative learning. Several reports that consciousness is associated with some form of memory imply that different forms of memories have a common feature contributing to consciousness. Based on a proposed synaptic mechanism capable of explaining different forms of memory, we developed a framework for consciousness. It is based on (...) the formation of semblance of sensory stimulus from 1)synaptic semblances when excitatory postsynaptic potentials arrive at functionally LINKed postsynaptic membranes, and 2) network semblances when these potentials summate to elicit action potential initiating activity in a network of neurons. It is then possible to derive a framework for consciousness as a multi-dimensional semblance. According to this framework, a continuum of semblances formed from background sensory stimuli and oscillating neuronal activities serve to maintain consciousness. Feasibility of this framework to explain various physiological and pathological states of consciousness, its subjective nature and qualia is examined. (shrink)

Purpose – This paper aims to extend the companion paper on “infant psychophysics”, which concentrated on the role of in-lab observers (watchers). Infants cannot report their own perceptions, so for five decades their detection thresholds for sensory stimuli were inferred from their stimulus-evoked behavior, judged by watchers. The inferred thresholds were revealed to inevitably be those of the watcher–infant duo, and, more broadly, the entire Laboratory. Such thresholds are unlikely to represent the finest stimuli that the infant can detect. (...) What, then, do they represent? Design/methodology/approach – Infants’ inferred stimulus-detection thresholds are hypothesized to be attentional thresholds, representing more-salient stimuli that overcome distraction. Findings – Empirical psychometric functions, which show “detection” performance versus stimulus intensity, have shallower slopes for infants than for adults. This (and other evidence) substantiates the attentional hypothesis. Research limitations/implications – An observer can only infer the mechanisms underlying an infant’s perceptions, not know them; infants’ minds are “Black Boxes”. Nonetheless, infants’ physiological responses have been used for decades to infer stimulus-detection thresholds. But those inferences ultimately depend upon observer-chosen statistical criteria of normality. Again, stimulus-detection thresholds are probably overestimated. Practical implications – Owing to exaggerated stimulus-detection thresholds, infants may be misdiagnosed as “hearing impaired”, then needlessly fitted with electronic implants. Originality/value – Infants’ stimulus-detection thresholds are re-interpreted as attentional thresholds. Also, a cybernetics concept, the “Black Box”, is extended to infants, reinforcing the conclusions of the companion paper that the infant-as-research-subject cannot be conceptually separated from the attending laboratory staff. Indeed, infant and staff altogether constitute a new, reflexive whole, one that has proven too resilient for anybody’s good. (shrink)

Understanding the mechanics of consciousness remains one of the most important challenges in modern cognitive science. One key step toward understanding consciousness is to associate unconscious physiological processes with subjective experiences of sensory, motor, and emotional contents. This article explores the role of various cellular membrane potential differences and how they give rise to the dynamic infrastructure of conscious experience. This article explains that consciousness is a body-wide, biological process not limited to individual organs because the mind and body (...) are unified as one entity; therefore, no single location of consciousness can be pinpointed. Consciousness exists throughout the entire body, and unified consciousness is experienced and maintained through dynamic repolarization during inhalation and expiration. Extant knowledge is reviewed to provide insight into how differences in cellular membrane potential play a vital role in the triggering of neural and non-neural oscillations. The role of dynamic cellular membrane potentials in the activity of the central nervous system, peripheral nervous system, cardiorespiratory system, and various other tissues (such as muscles and sensory organs) in the physiology of consciousness is also explored. Inspiration and expiration are accompanied by oscillating membrane potentials throughout all cells and play a vital role in subconscious human perception of feelings and states of mind. In addition, the role of the brainstem, hypothalamus, and complete nervous system (central, peripheral, and autonomic)within the mind-body space combine to allow consciousness to emerge and to come alive. This concept departs from the notion that the brain is the only organ that gives rise to consciousness. (shrink)

In Cybernetics (1961 Edition), Professor Norbert Wiener noted that “The role of information and the technique of measuring and transmitting information constitute a whole discipline for the engineer, for the neuroscientist, for the psychologist, and for the sociologist”. Sociology aside, the neuroscientists and the psychologists inferred “information transmitted” using the discrete summations from Shannon Information Theory. The present author has since scrutinized the psychologists’ approach in depth, and found it wrong. The neuroscientists’ approach is highly related, but remains unexamined. Neuroscientists (...) quantified “the ability of [physiological sensory] receptors (or other signal-processing elements) to transmit information about stimulus parameters”. Such parameters could vary along a single continuum (e.g., intensity), or along multiple dimensions that altogether provide a Gestalt – such as a face. Here, unprecedented scrutiny is given to how 23 neuroscience papers computed “information transmitted” in terms of stimulus parameters and the evoked neuronal spikes. The computations relied upon Shannon’s “confusion matrix”, which quantifies the fidelity of a “general communication system”. Shannon’s matrix is square, with the same labels for columns and for rows. Nonetheless, neuroscientists labelled the columns by “stimulus category” and the rows by “spike-count category”. The resulting “information transmitted” is spurious, unless the evoked spike-counts are worked backwards to infer the hypothetical evoking stimuli. The latter task is probabilistic and, regardless, requires that the confusion matrix be square. Was it? For these 23 significant papers, the answer is No. (shrink)

This paper reveals errors within Norwich et al.’s Entropy Theory of Perception, errors that have broad implications for our understanding of perception. What Norwich and coauthors dubbed their “informational theory of neural coding” is based on cybernetics, that is, control and communication in man and machine. The Entropy Theory uses information theory to interpret human performance in absolute judgments. There, the continuum of the intensity of a sensory stimulus is cut into categories and the subject is shown exemplar stimuli (...) of each category. The subject must then identify individual exemplars by category. The identifications are recorded in the Garner-Hake version of the Shannon “confusion matrix”. The matrix yields “H”, the entropy (degree of uncertainty) about what stimulus was presented. Hypothetically, uncertainty drops as a stimulus lengthens, i.e. a plot of H vs. stimulus duration should fall monotonically. Such “adaptation” is known for both sensation and firing rate. Hence, because “the physiological adaptation curve has the same general shape as the psychophysical adaptation curve”, Norwich et al. assumed that both have the same time course; sensation and firing rate were thus both declared proportional to H. However, a closer look reveals insurmountable contradictions. First, the peripheral neuron hypothetically cannot fire in response to a stimulus of a given intensity until after somehow computing H from its responses to stimuli of various intensities. Thus no sensation occurs until firing rate adapts, i.e. attains its spontaneous rate. But hypothetically, once adaptation is complete, certainty is reached and perception ends. Altogether, then, perception cannot occur until perception is over. Secondly, sensations, firing rates, and H’s are empirically not synchronous, contrary to assumption. In sum, the core concept of the cybernetics-based Entropy Theory of Perception, that is, that uncertainty reduction is the basis for perception, is irrational. (shrink)

Some sensory experiences are pleasant, some unpleasant. This is a truism. But understanding what makes these experiences pleasant and unpleasant is not an easy job. Various difficulties and puzzles arise as soon as we start theorizing. There are various philosophical theories on offer that seem to give different accounts for the positive or negative affective valences of sensory experiences. In this paper, we will look at the current state of art in the philosophy of mind, present the main (...) contenders, critically compare and contrast them. In particular, we want to examine how they handle the reason-giving power of affective states. We will look into two representationalist proposals (Evaluativism and Imperativism) and a functionalist proposal, and argue that, contrary to their own advertisements, the representationalist proposals don’t have good accounts of why and how sensory affect can motivate, rationalize, and justify subsequent behavior and intentional mental activity. We will show that our own functionalist proposal does a much better job in this regard, and that when the representationalist proposals are modified to do a better job, they fare better not because of their representationalist credentials but due to their functionalist ones. (shrink)

What are the sensory individuals of audition? What are the entities our auditory system attributes properties to? We examine various proposals about the nature of the sensory individuals of audition, and show that while each can account for some aspects of auditory perception, each also faces certain difficulties. We then put forward a new conception of sensory individuals according to which auditory sensory individuals are composite individuals. A feature shared by all existing accounts of sounds and (...) sources is that they postulate sensory individuals that are non-composite. They identify the sensory individual of sound hearing or source hearing with one type of entity in the environment, be they sound waves, vibrations, or interactions. We question this assumption and argue that our perceptual systems represent two or more aspects of the environment as a single sensory individual. Finally, we show that taking auditory individuals to be composite sensory individuals allows for an account of audition that is less problematic than its existing alternatives. (shrink)

Do sensory measurements deserve the label of “measurement”? We argue that they do. They fit with an epistemological view of measurement held in current philosophy of science, and they face the same kinds of epistemological challenges as physical measurements do: the problem of coordination and the problem of standardization. These problems are addressed through the process of “epistemic iteration,” for all measurements. We also argue for distinguishing the problem of standardization from the problem of coordination. To exemplify our claims, (...) we draw on olfactory performance tests, especially studies linking olfactory decline to neurodegenerative disorders. (shrink)

Philosophers of perception have been readier to postulate the existence of a visual field than to acknowledge sensory fields in other modalities. In this paper, I argue that the set of phenomenal features that philosophers have relied on when positing a visual field aptly characterise, mutatis mutandis, bodily sensation. I argue, in particular, that in localised bodily sensations we experience the body as a sensory field. I first motivate this claim for the case of haptic touch, and then (...) generalise it to other kinds of bodily sensation. I demonstrate the theoretical fruitfulness of this notion of a bodily field for the debate on the phenomenology of bodily ownership. (shrink)

The primary intention of this book is to elucidate the relations between sensory perception and art as a form of knowledge. This enables us to understand how different kinds of art are given their meaning not only from observation, resemblance and reason but also from an artist’s sensitivity to the inner form of sensory experience as it is realized in perception, reflection, memory and imagination. By assuming a number of different points of view, Part 1 shows how the (...) physical object and the act of sensory perception are logically interdependent, and I give my elaboration of this argument two kinds of emphasis. In the first place, it opposes all arguments that support a merging of the mental and physical, as in idealism, materialism, neutral monism and panpsychism. A conceptual distinction is observed because sensory perception gives the physical object its identity. This idea also implies that the physical object is only realized by sentient life - self-aware inner life and a world become possible simultaneously. The second emphasis concerns the mind-body problem, and towards the end of Part 1 I offer an argument which places this problem in a certain light by representing the brain not as a physical counterpart to inner experience but as essentially instrumental to perception and self-awareness, and related experience. The argument in Part 2 is distinguished by a sense of continuity between the nature of sensory perception and the formal resources of artists in both physical and literary media. Hence, in a discussion of Titian’s Assumption of the Virgin, I indicate ways in which the painter conveys the inner experience and character of the figures in the painting by means of compositional design, light and colour, and thereby uses these and other sensuous resources to portray human life and experience. This is followed by a discussion of two sonnets by Shakespeare, in which the same general aim is pursued by using the literary resources of figurative language. Finally, a discussion of Hamlet shows how, in this work, the augmentation of figurative language by dramatic form strengthens the view that art can provide a form of knowledge that is based as completely upon intuition about our sensory experience as it is upon reason and observation. Just as my (true) perception of a cup as a vessel for drinking tea or coffee arises immediately from past experience, so the dramatist can see immediately from his or her past experience how a character might perceive things and behave. -/- . (shrink)

Teleological accounts of sensory normativity treat normal functioning for a species as a standard: sensory error involves departure from normal functioning for the species, i.e. sensory malfunction. Straightforward reflection on sensory trade-offs reveals that normal functioning for a species can exhibit failures of accuracy. Acknowledging these failures of accuracy is central to understanding the adaptations of a species. To make room for these errors we have to go beyond the teleological framework and invoke the notion of (...) an ideal observer from vision science. The notion of an ideal observer also sheds light on the important distinction between sensory malfunction and sensory limitation. (shrink)

Is the brain the biological substrate of consciousness? Most naturalistic philosophers of mind have supposed that the answer must obviously be «yes » to this question. However, a growing number of philosophers working in 4e (embodied, embedded, extended, enactive) cognitive science have begun to challenge this assumption, arguing instead that consciousness supervenes on the whole embodied animal in dynamic interaction with the environment. We call views that share this claim dynamic sensorimotor theories of consciousness (DSM). Clark (2009) a founder and (...) leading proponent of the hypothesis of the extended mind, demurs, arguing that as matter of fact the biology of consciousness doesn’t allow for a brain, body and world boundary crossing architecture. We begin by looking at one of the arguments for DSM, the variable neural correlates argument. We then outline two criticisms that Clark has made of this argument and endorse his criticisms. However we finish up by using the case of sensory substitution to argue that something of this argument for DSM nevertheless survives. We suggest that Clark ought to concede sensory substitution as a case in which the conscious mind extends. (shrink)

In this article, we address an existing lacuna in the sociology of the senses, by employing sociological phenomenology to illuminate the under-researched sense of temperature, as lived by a social group for whom water temperature is particularly salient: competitive pool swimmers. The research contributes to a developing ‘sensory sociology’ that highlights the importance of the socio-cultural framing of the senses and ‘sensory work’, but where there remains a dearth of sociological exploration into senses extending beyond the ‘classic five’ (...) sensorium. Drawing on data from a three-year ethnographic study of competitive swimmers in the UK, our analysis explores the rich sensuousities of swimming, and highlights the role of temperature as fundamentally affecting the affordances offered by the aquatic environment. The article contributes original theoretical perspectives to the sociology of the senses and of sport in addressing the ways in which social actors in the aquatic environment interact, both intersubjectively and intercorporeally, as thermal beings. (shrink)

Sensory substitution devices make use of one substituting modality to get access to environmental information normally accessed through another modality . Based on behavioural and neuroimaging data, some authors have claimed that using a vision-substituting device results in visual perception. Reviewing these data, we contend that this claim is untenable. We argue that the kind of information processed by a SSD is metamodal, so that it can be accessed through any sensory modality and that the phenomenology associated with (...) the use of a SSD is best described in terms of spatial phenomenology, only. (shrink)

As recently highlighted, despite a burgeoning field of sensory ethnography, the practices, production, and accountability of the senses in specific social interactional contexts remain sociologically under-explored. To contribute original insights to a literature on the sensuous body in physical–cultural contexts, here we adopt an ethnomethodologically sensitive perspective to focus on the accomplishment, social organization, and accountability of sensoriality in interaction. Exploring instances of the senses at work in social interaction, we utilize data from two ethnographic research projects to investigate (...) the production of running-together and swimming-together by skilled, experienced practitioners. We focus on two interlinked sensory modalities: auditory attunement, and vision and intercorporeality, identified as key dimensions of sensory embodiment and “togethering” in these particular domains. (shrink)

The consensus in contemporary philosophy of mind is that how a perceptual experience represents the world to be is built into its sensory phenomenology. I defend an opposing view which I call ‘moderate separatism’, that an experience's sensory phenomenology does not determine how it represents the world to be. I argue for moderate separatism by pointing to two ordinary experiences which instantiate the same sensory phenomenology but differ with regard to their intentional content. Two experiences of an (...) object reflected in a mirror can possess the same spatial phenomenology while representing that object to occupy different spatial locations. So, contrary to the current consensus, the representation of spatial location is not fixed by an experience's sensory phenomenology. (shrink)

Is shadowboxing an effective form of functional exercise? What physiological and morphological changes result from an exercise program based exclusively on shadowboxing for 3 weeks? To date, no empirical research has focused specifically on addressing these questions. Since mixed martial arts (MMA) is the fastest growing sport in the world, and since boxing and kickboxing fitness classes are among the most popular in gyms and fitness clubs worldwide, the lack of research on shadowboxing and martial arts-based fitness programs in the (...) extant literature is a shortcoming that the present article aims to address. This case study involved a previously sedentary individual engaging in an exercise program based exclusively on shadowboxing for 3 weeks. Body composition and heart rate data were collected before, throughout, and upon completion of the 3-week exercise program to determine the effectiveness of shadowboxing for functional fitness purposes. An original shadowboxing program prepared by an Everlast Master Instructor and NASM Certified Personal Trainer (NASM-CPT) and Performance Enhancement Specialist (NASM-PES) was used for this 3-week period. The original shadowboxing program with goals, techniques, and combinations to work on throughout the 3-week program is included in this article. This case study demonstrates that a 3-week exercise program based exclusively on shadowboxing can increase aerobic capacity, muscle mass, bone mass, basal metabolic rate, and daily calorie intake, and decrease resting heart rate, fat mass, body fat percentage, and visceral fat rating in a previously sedentary individual. The results of this research demonstrate that shadowboxing can be a safe and effective form of exercise leading to morphological and physiological improvements including fat loss and increased aerobic capacity. The results of this research also demonstrate that the Tanita BC-1500 is a reliable tool for individuals to evaluate their own fitness progress over time. (shrink)

When a user integrates a sensory substitution device into her life, the process involves perceptual learning, that is, ‘relatively long-lasting changes to an organism’s perceptual system that improve its ability to respond to its environment’ (Goldstone 1998: 585). In this paper, I explore ways in which the extensive literature on perceptual learning can be applied to help improve sensory substitution devices. I then use these findings to answer a philosophical question. Much of the philosophical debate surrounding sensory (...) substitution devices concerns what happens after perceptual learning occurs. In particular, should the resultant perceptual experience be classified in the substituted modality (as vision), in the substituting modality (as auditory or tactile), or in a new sense modality? I propose a novel empirical test to help resolve this philosophical debate. (shrink)

Can a basic sensory property like a bare colour or tone be beautiful? Some, like Kant, say no. But Heidegger suggests, plausibly, that colours ‘glow’ and tones ‘sing’ in artworks. These claims can be productively synthesized: ‘glowing’ colours are not beautiful; but they are sensory forces—not mere ‘matter’, contra Kant—with real aesthetic impact. To the extent that it inheres in sensible properties, beauty is plausibly restricted to structures of sensory force. Kant correspondingly misrepresents the relation of beautiful (...) wholes to their parts. Beautiful form is not extrinsic to sensory force. Sensible beauty is just the holistic impact of agonistically-interacting sensory forces. When sensory forces interact hierarchically, their collective impact is closer to the sublime, in quality if not degree. The simplest sensory experience of sublimity is just the impact of radically intensified sensory forces, similar in kind if not degree to the individual ‘singing’ tones in a beautiful melody. (shrink)

According to a traditional view, perceptual experiences are composites of distinct sensory and cognitive components. This dual-component theory has many benefits; in particular, it purports to offer a way forward in the debate over what kinds of properties perceptual experiences represent. On this kind of view, the issue reduces to the questions of what the sensory and cognitive components respectively represent. Here, I focus on the former topic. I propose a theory of the contents of the sensory (...) aspects of perceptual experience that provides clear criteria for identifying what kinds of properties they represent. (shrink)

[This is the penultimate version, please send me an email for the final version]. Some sensations are pleasant, some unpleasant, and some are neither. Furthermore, those that are pleasant or unpleasant are so to different degrees. In this essay, I want to explore what kind of a difference is the difference between these three kinds of sensations. I will develop a comprehensive three-level account of sensory pleasure that is simultaneously adverbialist, functionalist and is also a version of a satisfied (...) experiential-desire account. (shrink)

This is the text of an invited talk exploring the connections between two apparently distinct notions of affect, sensory versus core affect. It is basically a progress report. It is exploratory and tentative. It starts from a mild puzzle about the apparent mismatch between the notion of affect that affective neuroscientists generally deploy and the notion of affect that emotion psychologists deploy. The notion favored by psychologists is the notion of core affect. The phenomenon studied by affective neuroscientists is (...) usually the notion of sensory affect. It's not clear how these two notions are related to each other. I'll present the main outlines of both notions, make some critical observations, and raise a few questions at the end. (shrink)

One of the central limitations of sensory substitution devices (SSDs) is their inability to reproduce the non-sensory feelings that are normally associated with visual experiences, especially hedonic and aesthetic responses. This limitation is sometimes reported to cause SSD users frustration. To make matters worse, it is unclear that improvements in acuity, bandwidth, or training will resolve the issue. Yet, if SSDs are to actually reproduce visual experience in its fullness, it seems that the reproduction of non-sensory feelings (...) will be of some importance. We offer a novel solution. Researchers can produce hedonic and aesthetic responses by eliciting these feelings artificially, pairing distal objects that should be pleasurable to pleasurable stimulus outputs from the SSD. We outline two strategies for accomplishing this: first, by means of a prefixed, hardwired, association of pleasant distal objects to pleasant stimulus outputs from the SSD; second, by means of a flexible, feedback-based association which creates associations based on a subject-directed matching of distal objects to patterns of stimuli from the SSD which the subject takes to have the corresponding hedonic properties. We evaluate some problems with both strategies, and we argue that the feedback-based strategy is more promising. Researchers can use this strategy to help the blind, allowing them to take pleasure in the objects they perceive using SSDs. (shrink)

It is hoped that modern sensory substitution and augmentation devices will be able to replace or expand our senses. But to what extent has this been achieved to date? To what extent are the experiences created by sensory substitution devices like the sensory experiences that we are trying to replace? To what extent can we augment people’s senses providing them with new information and new experiences? The first aim of this introduction is to delve deeply into this (...) question to discover the usefulness of these devices, to outline the different sorts of experience that might be created, and what the evidence tells us about these experiences. While there are some reasons to be hopeful about the powers of sensory substitution devices, there are also reasons to wonder whether they will ever really have the practical applications that we hope they might have. The second aim is to look to see whether the study of modern sensory substitution and augmentation devices can shed light on the nature of our senses and perception in general. Much of the philosophical, psychological, and neuroscientific work that takes place concerning sensory substitution and augmentation is keenly aware of the possibility that it might help our understanding and it seeks to comprehend many different aspects of perception. (shrink)