The third part of the Timaeus, where the account is focused on the cooperation of reason and necessity, has received far less attention than the opening two sections. Particularly, the description of irrigation, digestion and respiration constitutes a challenging passage that has been conspicuously overlooked by scholarly research. Virtually the only modern explanation for the passage was devised by Cornford, and despite several inaccuracies it has been unanimously accepted by all commentators. This paper will challenge Cornford’s interpretation, and use (...) some modern biological concepts to provide an alternative approach to the passage more compatible with an actual human body. (shrink)

Previous research has suggested that bodily signals from internal organs are associated with diverse cortical and subcortical processes involved in sensory-motor functions, beyond homeostatic reflexes. For instance, a recent study demonstrated that the preparation and execution of voluntary actions, as well as its underlying neural activity, are coupled with the breathing cycle. In the current study, we investigated whether such breathing-action coupling is limited to voluntary motor action or whether it is also present for mental actions not involving any overt (...) bodily movement. To answer this question, we recorded electroencephalography (EEG), electromyography (EMG), and respiratory signals while participants were conducting a voluntary action paradigm including self-initiated motor execution (ME), motor imagery (MI), and visual imagery (VI) tasks. We observed that the voluntary initiation of ME, MI, and VI are similarly coupled with the respiration phase. In addition, EEG analysis revealed the existence of readiness potential (RP) waveforms in all three tasks (i.e., ME, MI, VI), as well as a coupling between the RP amplitude and the respiratory phase. Our findings show that the voluntary initiation of both imagined and overt action is coupled with respiration, and further suggest that the breathing system is involved in preparatory processes of voluntary action by contributing to the temporal decision of when to initiate the action plan, regardless of whether this culminates in overt movements. -/- . (shrink)

Scholarship on Plato's Timaeus has paid relatively little attention to Tim. 77a–81, a seemingly disjointed passage on topics including plants, respiration, blood circulation, and musical sounds. Despite this comparative neglect, commentators both ancient and modern have levelled a number of serious charges against Timaeus' remarks in the passage, questioning the coherence and explanatory power of what they take to be a theory of respiration. In this paper, I argue that the project of 77a–81e is not to sketch theories (...) of respiration, circulation, and digestion, but to explain how the human body is maintained in light of and despite constant environmental depletion. Further, I argue that in order to understand this account of “the replenishing system,” we need to understand Timaeus' striking analogy of the fish trap or nassa. Commentators have generally focused directly on the workings of the bodily construction that Timaeus likens to a fish trap, but without considering how we should understand the analogy qua analogy. I develop a functional reading of the analogy that yields a coherent account of the replenishing system on which previous criticisms of Timaeus' remarks on respiration do not arise. Aside from lending greater unity to the passage, both internally and within its immediate context in the dialogue, this account of the replenishing system contributes to our understanding of Timaeus' reason-and-necessity explanatory framework as applied to the human body and has noteworthy implications for specific explanatory principles, in particular like-to-like motion and circular thrust. (shrink)

Respiration influences various pacemakers and rhythms of the body during inspiration and expiration but the underlying mechanisms are relatively unknown. Understanding this phenomenon is important, as breathing disorders, breath holding, and hyperventilation can lead to significant medical conditions. We discuss the physiological modulation of heart rhythm, blood pressure, sympathetic nerve activity, EEG, and other changes observed during inspiration and expiration. We also correlate the intracellular mitochondrial respiratory metabolic processes with real-time breathing and correlate membrane potential changes with inspiration and (...) expiration. We propose that widespread minor hyperpolarization occurs during inspiration and widespread minor depolarization occurs during expiration. This depolarization is likely a source of respiratory drive. Further knowledge of intracellular and extracellular ionic changes associated with respiration will enhance our understanding of respiration and its role as a modulator of cellular membrane potential. This could expand treatment options for a wide range of health conditions, such as breathing disorders, stress-related disorders, and further our understanding of the Hering–Breuer reflex and respiratory sinus arrhythmia. (shrink)

There are currently two legally established criteria for death: the irreversible cessation of circulation and respiration and the irreversible cessation of neurologic function. Recently, there have been technological developments that could undermine the irreversibility requirement. In this paper, I focus both on whether death should be identified as an irreversible state and on the proper scope of irreversibility in the biological definition of death. In this paper, I tackle the distinction between the commonsense definition of death and the biological (...) definition of death to show that even the commonsense concept of death is specified by biological facts. Resting on this argument, I argue that any definition of death is a posteriori. Thus, irreversibility is part of any definition of death because the actual phenomenon of death is irreversible. In addition, I show that the proper domain of irreversibility in a definition of death is circumscribed by physical possibilities and that irreversibility in the definition of death refers to current possibilities for the reversal of relevant biological processes. I conclude that, despite recent technological advancements, death is still irreversible. (shrink)

This paper proposes an abstract mathematical frame for describing some features of biological time. The key point is that usual physical (linear) representation of time is insufficient, in our view, for the understanding key phenomena of life, such as rhythms, both physical (circadian, seasonal …) and properly biological (heart beating, respiration, metabolic …). In particular, the role of biological rhythms do not seem to have any counterpart in mathematical formalization of physical clocks, which are based on frequencies along the (...) usual (possibly thermodynamical, thus oriented) time. We then suggest a functional representation of biological time by a 2-dimensional manifold as a mathematical frame for accommodating autonomous biological rhythms. The “visual” representation of rhythms so obtained, in particular heart beatings, will provide, by a few examples, hints towards possible applications of our approach to the understanding of interspecific differences or intraspecific pathologies. The 3- dimensional embedding space, needed for purely mathematical reasons, allows to introduce a suitable extra-dimension for “representation time”, with a cognitive significance. (shrink)

This integral investigation explored phenomenological and neurophysiologic, individual and collective dimensions of Christian Trinitarian meditation experiences in a volunteer, convenience sample of 10 practicing Christians, 6 men and 4 women, with a mean age of 48 years and an age range from 21 to 85 years. Participants meditated for a minimum period of 15 minutes, during which neurophysiologic data in the form of electroencephalographic (EEG), electromyographic (EMG), blood volume pulse (BVP) and respiratory activity were recorded. A phenomenological analysis indicated that (...) the meditation process generally involved a movement from body to mind to spirit as evident in reports of an increasingly relaxed, contented and focused state of consciousness characterised by Christian Trinitarian imagery, wonder, surrender, peace, bliss, openness and formlessness. The neuropsychological findings indicated significant increases, from baseline to meditation recordings, in the alpha and beta range, accompanied by increasing mean trends in the theta and gamma range, and decreasing mean trends in the delta range, EMG, BVP and respiration. Integrative findings indicated the practical theological value of small doses of Christian Trinity meditation to enhance spiritual life for those forms of waking, thinking, conscious behaviour needed in everyday world involvement and healing. Findings were discussed in relation to further integrative investigations and interventions with practical theological implications. (shrink)

Lorsque je me réveille le matin, je trouve ma femme à côté de moi et notre chien lové entre nous. Elle est calme et il est petit. Le faible bruit de leur respiration m’enveloppe tandis que je reprends progressivement conscience. Je repousse la couverture ; la fraîcheur de l’air me frappe. Je vais dans la cuisine et tourne le robinet pour me remplir un verre d’eau. Je suis l’aiguille des secondes sur...

In this paper I provide a commentary on and edition of the unpublished and apparently incomplete Medicina contracta of the Flemish philosopher Arnold Geulincx (1624– 1669). This short treatise, dating to c. 1668–1669, was not included in the edition of Geulincx’s works edited by J.P.N. Land, on the ground of its apparent unoriginality. However, it reveals the attempt, by Geulincx, to develop a medicine based on a new account of disease (intended in Cartesian-Platonic terms of the impossibility of the mind (...) using the body through animal spirits), and integrating avant-garde solutions typ- ical of iatrochemistry (in particular those of Franciscus Sylvius) and iatromechanics. The text, which I also consider in the light of Geulincx’s disputations in physiology, is moreover revelatory of his ongoing efforts in understanding the nature of respiration and its related diseases and conditions, such as apoplexy, and of his progressive, albeit not uncritical acceptance of Cartesianism. (shrink)

Descartes was born in La Haye (now Descartes) in Touraine and educated at the Jesuit college of La Fleche` in Anjou. Descartes’modern reputation as a rationalistic armchair philosopher, whose mind–body dualism is the source of damaging divisions between psychology and the life sciences, is almost entirely undeserved. Some 90% of his surviving correspondence is on mathematics and scientific matters, from acoustics and hydrostatics to chemistry and the practical problems of constructing scientific instruments. Descartes was just as interested in the motions (...) of matter as in the supernatural soul, and he advised against spending too much time on metaphysical inquiries which neglect imagination and the senses. After meeting the Dutch engineer Isaac Beeckman in 1618, Descartes became committed to a systematically ‘mechanical’account of nature. This involved explaining all natural processes in terms of interactions between microscopic material bodies in motion. Descartes modelled his physics and cosmology on the behaviour of fluids, which also have a distinctive and central role in his physiology: the key processes for natural philosophical investigation are the circulation and mutual displacement of constrained bodies, rather than the isolated collisions of atoms in a void. Descartes settled in Holland in 1628, and commenced an ambitious programme of physiological research. In 1630 he was ‘studying chemistry and anatomy simultaneously’, and in late 1632 he was ‘dissecting the heads of various animals’, in order to ‘explain what imagination, memory, etc. consist in’. By late 1633 Descartes had almost completed L’homme, the Treatise on Man; but he abandoned plans to publish it along with a work on matter theory and optics which relied on Copernican cosmology, after he heard of the condemnation of Galileo. L’homme was published posthumously in 1662 (Latin) and 1664 (French); not until 1972 was it fully translated into English. L’homme draws on many (mostly unnamed) Renaissance medical writers, and covers, firstly, a range of traditional physiological topics, such as digestion and respiration.. (shrink)

It is common to distinguish between “holist” and “reductionist” views of brain function, where the former envisions the brain as functioning as an indivisible unit and the latter as a collection of distinct units that serve different functions. Opposing reductionism, a number of researchers have pointed out that cortical network architecture does not respect functional boundaries, and the neuroanatomist V. Braitenberg proposed to understand the cerebral cortex as a “great mixing machine” of neuronal activity from sensory inputs, motor commands, and (...) intrinsically generated processes. In this paper, we offer a contextualization of Braitenberg’s point, and we review evidence for the interactions of neuronal activity from multiple sensory inputs and intrinsic neuronal processes in the cerebral cortex. We focus on new insights from studies on audiovisual interactions and on the influence of respiration on brain functions, which do not seem to align well with “reductionist” views of areal functional boundaries. Instead, they indicate that functional boundaries are fuzzy and context dependent. In addition, we discuss the relevance of the influence of sensory, proprioceptive, and interoceptive signals on cortical activity for understanding brain-body interactions, highlight some of the consequences of these new insights for debates on embodied cognition, and offer some suggestions for future studies. (shrink)

Understanding the autonomic nervous system and homeostatic changes associated with emotions remains a major challenge for neuroscientists and a fundamental prerequisite to treat anxiety, stress, and emotional disorders. Based on recent publications, the inter-relationship between respiration and emotions and the influence of respiration on autonomic changes, and subsequent widespread membrane potential changes resulting from changes in homeostasis are discussed. We hypothesize that reversing homeostatic alterations with meditation and breathing techniques rather than targeting neurotransmitters with medication may be a (...) superior method to address the whole body changes that occur in stress, anxiety, and depression. Detrimental effects of stress, negative emotions, and sympathetic dominance of the autonomic nervous system have been shown to be counteracted by different forms of meditation, relaxation, and breathing techniques. We propose that these breathing techniques could be used as firstline and supplemental treatments for stress, anxiety, depression, and some emotional disorders. (shrink)

A ventilator is a device that provides cool air by moving the air in or out of the lungs, inhaling a patient who is not fit to smell, or breathing properly. In this paper, a resistive chest belt sensorbased mechanical ventilator is designed to provide the COVID-19 patient with the volume of air you need to deliver with the expansion of the patient's chest in need of more air. The resistive band sensor senses the expansion of the patient's chest and (...) controls the solenoid valve attached to the oxygen compressor. The function of the respirator is tested with the MATLAB / Simulink tool with the help of a Proportional Integral Derivative (PID) Controller and a promising result obtained. (shrink)

We have been accustomed at least since Kant and mainstream history of philosophy to distinguish between the ‘mechanical’ and the ‘teleological’; between a fully mechanistic, quantitative science of Nature exemplified by Newton and a teleological, qualitative approach to living beings ultimately expressed in the concept of ‘organism’ – a purposive entity, or at least an entity possessed of functions. The beauty of this distinction is that it seems to make intuitive sense and to map onto historical and conceptual constellations in (...) medicine, physiology and the related natural -philosophical discussions on the status of the body versus that of the machine. In this presentation I argue that the distinction between mechanism and teleology is imprecise and flawed, on the basis of a series of examples: the presence of ‘functional’ or ‘purposive’ features even in Cartesian physiology; work such as that of Richard Lower’s on animal respiration; the fact that the model of the ‘body-machine’ is not at all a mechanistic reduction of organismic properties to basic physical properties but on the contrary a way of emphasizing the uniqueness of organic life; and the concept of ‘animal economy’ in vitalist medical theory, which I present as a kind of ‘teleo-mechanistic’ concept of organism – neither mechanical nor teleological. (shrink)

The focal point of this chapter is to discuss the concept of computer regulated testing and its implications in an era of Severe Acute Respiratory Syndrome (SARS) related infection pandemics. This is especially significant because during the outbreak of most SARS-related diseases (like the COVID-19), social and physical distancing is advocated by the government of different nations. SARS-related diseases are caused by a virus known as the coronavirus which affects the respiration of infected persons or animals. These diseases can (...) be spread through air if droplets from an infected get to a non-tainted individual. (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)