Lockean views of personal identity maintain that we are essentially persons who persist diachronically by virtue of being psychologically continuous with our former selves. In this article, I present a novel objection to this variant of psychological accounts, which is based on neurophysiological characteristics of the brain. While the mental states that constitute said psychological continuity reside in the cerebral hemispheres, so that for the former to persist only the upper brain must remain intact, being conscious additionally requires that a (...) structure originating in the brainstem—the ascending reticular activating system—be functional. Hence, there can be situations in which even small brainstem lesions render individuals irreversibly comatose and thus forever preclude access to their mental states, while the neural correlates of the states themselves are retained. In these situations, Lockeans are forced to regard as fulfilled their criterion of diachronic persistence since psychological continuity, as they construe it, is not disrupted. Deeming an entity that is never again going to have any mental experiences to be a person, however, is an untenable position for a psychological account to adopt. In their current form, Lockean views of personal identity are therefore incompatible with human neurophysiology. (shrink)

Gray hypothesizes that the contents of consciousness correspond to the outputs of a subicular (hippocampal/temporal lobe) comparator that compares the current state of the organism's perceptual world with a predicted state. I argue that Gray has identified a key contributing system to conscious awareness, but that his model is inadequate for explaining how conscious contents are generated in the brain. An alternative model is offered.

During the latter part of the nineteenth century our description of nerve cell structure underwent a relatively unrecognized, though fundamental, transformation-a quiet revolution of sorts. The central problem facing scientists in neurology (the study of the nervous system) was a related pair: are nerve cells continuous with each other or not, and how is information conducted? Microscope resolution and staining techniques were inadequate at the time to yield definitive proof either way. I contend that explanatory coherence provides a means (...) to elucidate this instance of theory change in the history of science. The means of elucidation will be Thagard's computational model of explanatory coherence, ECHO (). (shrink)

This review considers a number of recent theories on the neural basis of consciousness, with particular attention to the theories of Bogen, Crick, Llinás, Newman, and Changeux. These theories allot different roles to various key brain areas, in particular the reticular and intralaminar nuclei of the thalamus and the cortex. Crick's hypothesis is that awareness is a function of reverberating corticothalamic loops and that the spotlight ofintramodalattention is controlled by the reticular nucleus of the thalamus. He also proposed (...) different mechanisms for attention and intention . The current review presents a new hypothesis, based on elements from these hypotheses, includingintermodalattention and olfaction and pain, which may pose problems for Crick's original theory. This work reviews the possible role in awareness and intermodal attention and intention of the cholinergic system in the basal forebrain and the tegmentum; the reticular, the intralaminar, and the dorsomedial thalamic nuclei; the raphe and locus coeruleus; the reticular formation; the ventral striatum and extended amygdala; insula cortex, and other selected cortical areas. Both clinical and basic research data are covered. The conclusion is reached that the brain may work by largely nonlinear parallel processing and much intramodal shifts of attention may be effected by intracortical, or multiple corticothalamic mechanisms . But this is constrained by the functional anatomy of the circuits concerned and waking “awareness” is modulated by the many “nonspecific” systems . But the principal agents for intermodal attention shifts, the “searchlight,” may be two key nuclei of the cholinergic system in the mesencephalon. Clinical loss of consciousness results from damage to these nuclei but not from damage to the cholinergic nucleus basalis of the basal forebrain. (shrink)

In this report, we describe the case of a patient who has remained in a comatose state for more than one year after a traumatic and hypoxic brain injury. This state, which we refer to as long-lasting coma (LLC), may be a disorder of consciousness with significantly different features from those of conventional coma, the vegetative state, or brain death. On the basis of clinical, neurophysiological and neuroimaging data, we hypothesize that a multilevel involvement of the ascending reticular activating (...) system is required in LLC. This description may be useful for the identification of other patients suffering from this severe disorder of consciousness, which raises important ethical issues. (shrink)

Merker suggests that the thalamocortical system is not an essential system for consciousness, but, instead, that the midbrain reticular system is responsible for consciousness. Indeed, the latter is a crucial system for consciousness, when consciousness is regarded as the waking state. However, when consciousness is regarded as phenomenal consciousness, for which experience and perception are essential elements, the thalamocortical system seems to be indispensable. (Published Online May 1 2007).

It is traditionally believed that cerebral activation (the presence of low voltage fast electrical activity in the neocortex and rhythmical slow activity in the hippocampus) is correlated with arousal, while deactivation (the presence of large amplitude irregular slow waves or spindles in both the neocortex and the hippocampus) is correlated with sleep or coma. However, since there are many exceptions, these generalizations have only limited validity. Activated patterns occur in normal sleep (active or paradoxical sleep) and during states of anesthesia (...) and coma. Deactivated patterns occur, at times, during normal waking, or during behavior in awake animals treated with atropinic drugs. Also, the fact that patterns characteristic of sleep, arousal, and waking behavior continue in decorticate animals indicates that reticulo-cortical mechanisms are not essential for these aspects of behavior. (shrink)

A unifying theory of general anesthetic-induced unconsciousness must explain the common mechanism through which various anesthetic agents produce unconsciousness. Functional-brain-imaging data obtained from 11 volunteers during general anesthesia showed specific suppression of regional thalamic and midbrain reticular formation activity across two different commonly used volatile agents. These findings are discussed in relation to findings from sleep neurophysiology and the implications of this work for consciousness research. It is hypothesized that the essential common neurophysiologic mechanism underlying anesthetic-induced unconsciousness is, as (...) with sleep-induced unconsciousness, a hyperpolarization block of thalamocortical neurons. A model of anesthetic-induced unconsciousness is introduced to explain how the plethora of effects anesthetics have on cellular functioning ultimately all converge on a single neuroanatomic/neurophysiologic system, thus providing for a unitary physiologic theory of narcosis related to consciousness. (shrink)

Based on recent insight into the thalamocortical system and its role in perception and conscious experience, a unified pathophysiological framework for hallucinations in neurological and psychiatric conditions is proposed, which integrates previously unrelated neurobiological and psychological findings. Gamma-frequency rhythms of discharge activity from thalamic and cortical neurons are facilitated by cholinergic arousal and resonate in networks of thalamocortical circuits, thereby transiently forming assemblies of coherent gamma oscillations under constraints of afferent sensory input and prefrontal attentional mechanisms. If perception is (...) based on synchronisation of intrinsic gamma activity in the thalamocortical system, then sensory input to specific thalamic nuclei may merely play a constraining role. Hallucinations can be regarded as underconstrained perceptions that arise when the impact of sensory input on activation of thalamocortical circuits and synchronisation of thalamocortical gamma activity is reduced. In conditions that are accompanied by hallucinations, factors such as cortical hyperexcitability, cortical attentional mechanisms, hyperarousal, increased noise in specific thalamic nuclei, and random sensory input to specific thalamic nuclei may, to a varying degree, contribute to underconstrained activation of thalamocortical circuits. The reticular thalamic nucleus plays an important role in suppressing random activity of relay cells in specific thalamic nuclei, and its dysfunction may be implicated in the biological vulnerability to hallucinations in schizophrenia. Combined with general activation during cholinergic arousal, this leads to excessive disinhibition in specific thalamic nuclei, which may allow cortical attentional mechanisms to recruit thalamic relay cells into resonant assemblies of gamma oscillations, regardless of their actual sensory input, thereby producing an underconstrained perceptual experience. Key Words: Charles Bonnet syndrome; gamma oscillations; hallucinations; late paraphrenia; Lewy body dementia; perception; schizophrenia; thalamocortical system. (shrink)

A tacit assumption since the 19th Century has been that the neocortex serves as the "seat of consciousness." An unexpected challenge to that assumption arose in 1949 with the discovery that high-frequency EEG activation associated with an alert state requires the intactness of the brainstem reticular formation. This discovery became the impetus for nearly three decades of research on what came to be known as the reticular activating system. By the 1970s, however, methodological and philosophical controversies led (...) to general abandonment of subcortical theories of attention and consciousness, with a return to an almost exclusive focus upon the cortex. With recent advances in the neurosciences the focus is shifting once more, this time to the unique contributions of cortical, thalmic, and brainstem structures in mediating selective attention and perceptual awareness. This paper offers a nontechnical review of the history of these developments up to contemporary interest in the putative role of oscillatory EEG patterns in the integration of perceptual features of experience. It puts forward the thesis that a key to understanding attention and consciousness is an appreciation of contributions of the thalmus to these cognitive processes. (shrink)

Primordial emotions are the subjective element of the instincts which are the genetically programmed behaviour patterns which contrive homeostasis. They include thirst, hunger for air, hunger for food, pain and hunger for specific minerals etc.There are two constituents of a primordial emotion—the specific sensation which when severe may be imperious, and the compelling intention for gratification by a consummatory act. They may dominate the stream of consciousness, and can have plenipotentiary power over behaviour.It is hypothesized that early in animal evolution (...) complex reflex mechanisms in the basal brain subserving homeostatic responses, in concert with elements of the reticular activating system subserving arousal, melded functionally with regions embodied in the progressive rostral development of the telencephalon. This included the emergent limbic and paralimbic areas, and the insula. This phylogenetically ancient organization subserved the origin of consciousness as the primordial emotion, which signalled that the organisms existence was immediately threatened. Neuroimaging confirms major activations in regions of the basal brain during primordial emotions in humans. The behaviour of decorticate humans and animals is discussed in relation to the possible existence of primitive awareness.Neuroimaging of the primordial emotions reveals that rapid gratification of intention by a consummatory act such as ingestion causes precipitate decline of both the initiating sensation and the intention. There is contemporaneous rapid disappearance of particular regions of brain activation which suggests they may be part of the jointly sufficient and severally necessary activations and deactivations which correlate with consciousness [Crick, F. & Koch, C. . A framework for consciousness. NatureNeuroscience,6, 119–126]. (shrink)

Many traditions in the East have proposed that consciousness without content is possible and could be achieved with mental training. However, it is not clear whether such a state is possible given that intentionality is a critical property of mentality and consciousness in many theories of consciousness. A prominent recent attempt to account for such states of “minimal phenomenal experience” is the ascending reticular arousal system (ARAS) model, which proposes a specific type of non-conceptual representational content to address (...) such a state. Consciousness without content can also be understood by studying related or similar states of minimal phenomenal experience and this paper discusses such findings from such states including dreamless sleep experience and their implications. One way to argue for the need for proposing consciousness without content is to locate a property of consciousness that would necessitate postulating it. A continuous state of consciousness without content may be needed to understand continuity of conscious experience. Finally, I discuss the implications of consciousness without content for current theories of consciousness. (shrink)

I have argued in other work that emotion, attentional functions, and executive functions are three interpenetrant global state variables, essentially differential slices of the consciousness pie. This paper will outline the columnar architecture and connectivities of the PAG (periaqueductal gray), its role in organizing prototype states of emotion, and the re-entry of PAG with the extended reticular thalamic activating system (“ERTAS”). At the end we will outline some potential implications of these connectivities for possible functional correlates of PAG (...) networks that are just starting to be mapped. Overall, we will look at many lines of evidence that PAG should be conceptualized as a peri-reticular structure that has a foundational role in emotion, in generating the meaningful organization of behavior by the brain through prototype emotional states, and in allowing the various emotional systems to globally influence and tune both the forebrain and brainstem. Finally, we address implications of these concepts for what is currently understood about consciousness, underlining the need for somewhat more humility within consciousness studies about our current level of understanding of consciousness in the brain, combined with a deeper appreciation of the intrinsic connections between emotion and consciousness. One hopes that more concerted empirical interest in structures underneath the thalamus, combined with a deeper appreciation for the fundamental role that organismic and social value must have in bootstrapping awareness in the developing brain, would begin more widely to influence the fundamental lines of neuroscientific research in both emotion studies and consciousness studies. (shrink)

The Global Workspace Theory and Information Integration Theory are two of the most currently accepted consciousness models; however, these models do not address many aspects of conscious experience. We compare these models to our previously proposed consciousness model in which the thalamus fills-in processed sensory information from corticothalamic feedback loops within a proposed 3D default space, resulting in the recreation of the internal and external worlds within the mind. This 3D default space is composed of all cells of the body, (...) which communicate via gap junctions and electrical potentials to create this unified space. We use 3D llustrations to explain how both visual and non-visual sensory information may be filled-in within this dynamic space, creating a unified seamless conscious experience. This neural sensory memory space is likely generated by baseline neural oscillatory activity from the default mode network, other salient networks, brainstem, and reticular activating system. (shrink)

_Spiritual practices have been proposed to have many beneficial effects as far as mental health is concerned. The exact neural basis of these effects is slowly coming to light and different imaging techniques have elucidated the neural basis of meditative practices. The evidence though preliminary and based on studies replete with methodological constraints, points toward the involvement of the prefrontal and parietal cortices. The available data on meditation focus on activated frontal attentional network. Neuroimaging studies have shown that meditation results (...) in an activation of the prefrontal cortex, activation of the thalamus and the inhibitory thalamic reticular nucleus and a resultant functional deafferentation of the parietal lobe. The neurochemical change as a result of meditative practices involves all the major neurotransmitter systems. The neurotransmitter changes contribute to the amelioration of anxiety and depressive symptomatology and in part explain the psychotogenic property of meditation. This overview highlights the involvement of multiple neural structures, the neurophysiological and neurochemical alterations observed in meditative practices._. (shrink)

This paper presents a case in whom a differential diagnosis of akinetic mutism with a disorder of consciousness was made using diffusion tensor tractography. A 69-year-old female patient was diagnosed with subarachnoid hemorrhage, intraventricular hemorrhage, and intracerebral hemorrhage produced by the subarachnoid hemorrhage. She exhibited impaired consciousness with a Coma Recovery Scale-Revised score of 13 until 1 month after onset. Her impaired consciousness recovered slowly to a normal state according to the Coma Recovery Scale-Revised at 7 weeks after onset. On (...) the other hand, she exhibited the typical clinical features of akinetic mutism. On the DTT performed at 1-month, the upper, and lower dorsal ascending reticular activating systems, which are related to a disorder of consciousness, showed an almost normal state. In contrast, the prefronto-caudate and prefronto-thalamic tracts, which are related to akinetic mutism, showed severe injuries. These DTT results suggested that the patient's main clinical features were not a disorder of consciousness but akinetic mutism. Therefore, DTT for the ascending reticular activating system, and the prefronto-caudate and prefronto-thalamic tracts could provide additional evidence for a differential diagnosis of DOC and AM at the early stages of stroke. (shrink)

Possible systemic effects of general anesthetic agents on neural information processing are discussed in the context of the thalamocortical suppression hypothesis presented by Drs. Alkire, Haier, and Fallon (this issue) in their PET study of the anesthetized state. Accounts of the neural requisites of consciousness fall into two broad categories. Neuronal-specificity theories postulate that activity in particular neural populations is sufficient for conscious awareness, while process-coherence theories postulate that particular organizations of neural activity are sufficient. Accounts of anesthetic narcosis, on (...) the other hand, explain losses of consciousness in terms of neural signal-suppressions, transmission blocks, and the disruptions of signal interpretation. While signal-suppression may account for the actions of some anesthetic agents, the existence of anesthetics, such as choralose, that cause both loss of consciousness and elevated discharge rates, is problematic for a general theory of narcosis that is based purely on signal suppression and transmission-block. However, anesthetic agents also alter relative firing rates and temporal discharge patterns that may disrupt the coherence of neural signals and the functioning of the neural networks that interpret them. It is difficult at present, solely on the basis of regional brain metabolic rates, to test process-coherence hypotheses regarding organizational requisites for conscious awareness. While these pioneering PET studies have great merit as panoramic windows of mind-brain correlates, wider ranges of theory and empirical evidence need to be brought into the formulation of truly comprehensive theories of consciousness and anesthesia. (shrink)

The study of consciousness is poised today at interesting crossroads. There has been a surge of research into various neurobiological underpinnings of consciousness in the past decade. The present article looks at the theories regarding this complex phenomenon, especially the ones that neurobiology, cognitive neuroscience and cognitive psychology have to offer. We will first discuss the origin and etymology of word consciousness and its usage. Neurobiological correlates of consciousness are discussed with structures like the ascending reticular activating system, (...) the amygdala, the cerebellum, the thalamus, the frontoparietal circuits, the prefrontal cortex and the precuneus. The cellular and microlevel theories of consciousness and cerebral activity at the neuronal level contributing to consciousness are highlighted, along with the various theories posited in this area. The role of neuronal assemblies and circuits along with firing patterns and their ramifications for the understanding of consciousness are discussed. A section on the role of anaesthesia and its links to consciousness is presented, along with details of split-brain studies in consciousness and altered states of awareness, including the vegetative states. The article finally discusses the progress cognitive psychology has made in identifying and theorising various perspectives of consciousness, perceptual awareness and conscious processing. Both recent and past researches are highlighted. The importance and salient features of each theory are discussed along with the pitfalls, if present. A need for integration of various theories to understand consciousness from a holistic perspective is stressed, to enable one to reach a theory that explains the ultimate neurobiology of consciousness. (shrink)

A neurosurgical view of consciousness is presented. It is biased by our need to deal with coma. The concept of primary or neurosurgical consciousness is discussed, and the anatomy, physiology, pathology and clinical features described in a simple a way. It is suggested that the dynamic interaction between the reticular activating system and the cerebral cortex is the anatomic and physiologic basis for primary consciousness. It is emphasised that this in no way diminishes the role of the cortex (...) in either primary or higher-order consciousness. In essence, a presentation is made of the neurosurgical view of cortex-brainstem inter- relationships, and the importance of this interrelationship to consciousness. (shrink)

Part I of this two-part paper provided a broad overview of clinical and experimental findings bearing on the neural correlates of conscious processes. It was argued that several neurocognitive models related to: orienting to the outer world, dream sleep, and the integration of sensory-motor representations, converge upon a core ‘conscious system’, dubbed the extended reticular-thalamic activating system . The functions of the ERTAS, which shares extensive projections with the cerebral cortex, are mostly ‘implicit’, in contrast to the (...) explicit representation of conscious content within the neocortex. Part II expands this ERTAS model to encompass: the generation of coherent patterns of EEG activation, the integration of distributed cortical processes into a stream of unified percepts , and selective attention, as well as links between the ERTAS and systems providing the neural substrates for episodic memory and volition. (shrink)

The will is one of the three pillars of the trilogy of mind that has pervaded Western thought for millennia, the other two being affectivity and cognition (Hilgard 1980). In the past century, the concept of will was imperceptibly replaced by the cognitive-oriented behavioral qualifiers “voluntary,” “goal-directed,” “purposive,” and “executive” (Tranel et al. 1994), and has lost much of its heuristic merits, which are related to the notion of “human autonomy” (Lhermitte 1986). We view catatonia as the clinical expression of (...) impairment of the brain mechanisms that promote human will. Catatonia is to the brain systems engaged in will, as coma is to the reticular ascending systems that promote sleep and wakefulness (Plum 1991). (shrink)

Subcortical substrates for behavioural integration include the fore/midbrain nuclei of the basal ganglia and the hindbrain medial reticular formation. The midbrain superior colliculus requires basal ganglia disinhibition in order to generate orienting movements. The colliculus should therefore be seen as one of many competitors vying for control of the body's effector systems with the basal ganglia acting as the key arbiter. (Published Online May 1 2007).

The study of consciousness is poised today at interesting crossroads. There has been a surge of research into various neurobiological underpinnings of consciousness in the past decade. The present article looks at the theories regarding this complex phenomenon, especially the ones that neurobiology, cognitive neuroscience and cognitive psychology have to offer. We will first discuss the origin and etymology of word consciousness and its usage. Neurobiological correlates of consciousness are discussed with structures like the ascending reticular activating system, (...) the amygdala, the cerebellum, the thalamus, the frontoparietal circuits, the prefrontal cortex and the precuneus. The cellular and microlevel theories of consciousness and cerebral activity at the neuronal level contributing to consciousness are highlighted, along with the various theories posited in this area. The role of neuronal assemblies and circuits along with firing patterns and their ramifications for the understanding of consciousness are discussed. A section on the role of anaesthesia and its links to consciousness is presented, along with details of split-brain studies in consciousness and altered states of awareness, including the vegetative states. The article finally discusses the progress cognitive psychology has made in identifying and theorising various perspectives of consciousness, perceptual awareness and conscious processing. Both recent and past researches are highlighted. The importance and salient features of each theory are discussed along with the pitfalls, if present. A need for integration of various theories to understand consciousness from a holistic perspective is stressed, to enable one to reach a theory that explains the ultimate neurobiology of consciousness. (shrink)

In this manuscript Hobson et al. propose a model exploring qualitative differences between the three states of consciousness, waking, NREM sleep, and REM sleep, in terms of state-related brain activity. The model consists of three factors, each of which varies along a continuum, creating a three-dimensional space: activation (A), information flow (I), and mode of information processing (M). Hobson has described these factors previously (1990; 1992a). Two of the dimensions, activation and modulation, deal directly with subcortical influences upon cortical structures (...) – the reticular activation system, with regard to the activation dimension and the locus coeruleus and the pontine raphe neuclei, with regard to the modulation dimension. The focus of this review is a further exploration of the interaction between dreaming and the cortical and subcortical structures relevant to REM sleep eye movements. [Hobson et al. ]. (shrink)

When does a human being cease to exist? For millennia, the answer to this question had remained largely unchanged: death had been diagnosed when heartbeat and breathing were permanently absent. Only comparatively recently, in the 1950s, rapid developments in intensive-care medicine called into question this widely accepted criterion. What had previously been deemed a permanent cessation of vital functions suddenly became reversible. -/- A new criterion of death was needed. It was suggested that the destruction of the brain could indicate (...) the death of the organism in the presence of external life support. Soon the so-called brain death became the new worldwide standard. In recent years, however, doubts about this neurological criterion have been growing. Is brain death really our death? -/- This is the question that this thesis seeks to answer. To this end, we shall connect the medical debate about the definition of death to the philosophical debate about personal identity. While we will find that the destruction of its brain does in fact not correspond to an organism’s death, we shall also ask whether the assumption that we are essentially organisms is correct. May brain death be the ceasing to exist of a different entity? -/- Substituting clinical case reports and considerations about human physiology for the use of thought experiments, the thesis takes a novel and philosophically unconventional approach to the problem of what we essentially are. We shall analyse various pathological conditions and their respective effects on the bodily and mental characteristics of our existence. We will conclude that brain death is indeed our death – but for reasons entirely different from those cited in the original justification of this criterion. (shrink)

The theses in this book are: 1) the tension between the Leibnizian theory of the tropes and their use is resolved in a "pragmatic of discourse" that gives the metaphor a richer dimension than the theorized one, that is, that of "a mechanism capable of combining elements coming from different conceptual spaces into a new metaphorical conceptual space, 'shapeless' to which the metaphor itself provides an adequate language to describe and structure it"; 2) the role of metaphors is placed for (...) Leibniz in the context of a 'multi-method' idea that combines the inventive and the formalizing moment and allows for a multiplicity of directions; 3) the Leibniz system is organized according to a 'logic' that is not deductive but analogical; 4) the valid relations in the system are not only connections of a logical nature; on the contrary, the organization is 'reticular', and the primacy of a relation depends from time to time on the prevalence assigned to a metaphor according to the problem being faced; 5) Leibniz's central metaphors are "emerging parts of a wider submerged translation", i.e. they are both expression and conceptualizing vehicle of a cognitive strategy that wants to govern the complexity of knowledge by organizing it around themes; this strategy is alternative to the Cartesian formulation of "Method" based on the disjunction of objects and notions and instead gives philosophical expression to the Baroque sense of the constant mutability that rules the world. (shrink)

When an individual is comatose while parts of her brain remain functional, the question arises as to whether any mental characteristics are still associated with this brain, that is, whether the person still exists. Settling this uncertainty requires that one becomes clear about two issues: the type of functional loss that is associated with the respective profile of brain damage and the persistence conditions of persons. Medical case studies can answer the former question, but they are not concerned with the (...) latter. Conversely, in the philosophical literature, various accounts of personal identity are discussed, but usually detached from any empirical basis. Only uniting the two debates and interpreting the real-life configurations of brain damage through the lens of the philosophical concepts enables one to make an informed judgment regarding the persistence of comatose persons. Especially challenging are cases in which three mental characteristics that normally occur together—wakefulness, awareness and memory storage—come apart. These shall be the focus of this paper. (shrink)

In this essay, I focus on two questions. First, what is Kant's understanding of the sense in which our faculties form a unified system? And, second, what are the implications of this for the metaphysical relationships between the faculties within this system? To consider these questions, I begin with a brief discussion of Longuenesse's groundbreaking work on the teleological unity of the understanding as the faculty for judgment. In doing so, I argue for a generalization of Longuenesse's account (...) along two dimensions. The result is a picture of our faculties as forming a teleological system—unified under the overarching aims of reason as the highest rational faculty. Then I discuss the recent debate between “additive” and “transformative” interpretations of the relationship between sensibility and the understand- ing, before proposing that we should interpret Kant as endorsing a moderate form of the “transformative” reading, which captures important elements of both the “additive” and the “transformative” account. (shrink)

This paper is an edited form of a letter written by the two authors (in the name of Tarski) to Wolfram Schwabhäuser around 1978. It contains extended remarks about Tarski's system of foundations for Euclidean geometry, in particular its distinctive features, its historical evolution, the history of specific axioms, the questions of independence of axioms and primitive notions, and versions of the system suitable for the development of 1-dimensional geometry.

Face perception, perhaps the most highly developed visual skill in humans, is mediated by a distributed neural system in humans that is comprised of multiple, bilateral regions. We propose a model for the organization of this system that emphasizes a distinction between the representation of invariant and changeable aspects of faces. The representation of invariant aspects of faces underlies the recognition of individuals, whereas the representation of changeable aspects of faces, such as eye gaze, expression, and lip movement, (...) underlies the perception of information that facilitates social communication. The model is also hierarchical insofar as it is divided into a core system and an extended system. The core system is comprised of occipitotemporal regions in extrastriate visual cortex that mediate the visual analysis of faces. In the core system, the representation of invariant aspects is mediated more by the face-responsive region in the fusiform gyrus, whereas the representation of changeable aspects is mediated more by the face-responsive region in the superior temporal sulcus. The extended system is comprised of regions from neural systems for other cognitive functions that can be recruited to act in concert with the regions in the core system to extract meaning from faces. (shrink)

This article draws on scientific explanations of obesity to motivate the creation of a system of paternalistic public health interventions into the obesity epidemic. Libertarian paternalists argue that paternalism is warranted in light of the cognitive limits of human decision-making abilities. There are further, specific biological limits on our capacity to choose and maintain a healthy diet. These biological facts strengthen the general motivation for libertarian paternalism. As a consequence, the creation of a system of paternalistic public health (...) interventions into the obesity epidemic is warranted. (shrink)

Chest pain is the pain felt in the chest by infants, children and adolescents. In most cases the pain is not associated with the heart. It is mainly recognized by the observance or report of pain by the infant, child or adolescent by reports of distress by parents or care givers. Chest pain is not unusual in children. Lots of children are seen in ambulatory clinics, emergency rooms and hospitals and cardiology clinics. Usually there is a benign cause for the (...) pain for utmost children. Certain patients have conditions that are serious and perhaps life-threatening. Chest pain in pediatric patients needs careful physical examination and a detailed history that would point to the possibility of a serious cause. Researches of pediatric chest pain are scarce. It has been difficult to create evidence-based guidelines for evaluation. In this paper we propose an expert system to help doctors and parents, and care giver in diagnosing chest pain in infants and children. This expert System is design and implemented in SL5 Object language. (shrink)

We present an axiom system for basic hybrid logic extended with propositional quantifiers (a second-order extension of basic hybrid logic) and prove its (basic and pure) strong completeness with respect to general models.

Although moral distress is now a well-recognized phenomenon among all of the healthcare professions, few evidence-based strategies have been published to address it. In morally distressing situations, the “presenting problem” may be a particular patient situation, but most often signals a deeper unit- or system-centered issue. This article describes one institution’s ongoing effort to address moral distress in its providers. We discuss the development and evaluation of the Moral Distress Consultation Service, an interprofessional, unit/system-oriented approach to addressing and (...) ameliorating moral distress. (shrink)

In order to understand Hegel's approach to philosophy, we need to ask why, and how, he reacts to the well-known criticism of German Romantics, like Novalis and Friedrich Schlegel, against philosophical system building in general, and against Kant's system in particular. Hegel's encyclopedic system is a topical ordering of categorically different ontological realms, corresponding to different conceptual forms of representation and knowledge. All in all it turns into a systematic defense of Fichte's doctrine concerning the primacy of (...) us as actors with respect to any knowledge claim or scientific theory. Hegel's limitations of the principle of causality and of the possibility of using mathematical methods in science show, in fact, how a merely compatibilist solution of Kant's third antinomy can be overcome. (shrink)

Mozart's great opera, Don Giovanni, poses a number of significant philosophical and aesthetic challenges, and yet it remains, for the most part, little discussed by contemporary philosophers. A notable exception to this is Bernard Williams's important paper, ‘Don Juan as an Idea’, which contains an illuminating discussion of Kierkegaard's ground-breaking interpretation of the opera, ‘The Immediate Erotic Stages or the Musical-Erotic’, in Either/Or. Kierkegaard's pseudonymous author's approach here is, in some respects, reminiscent of a currently rather fashionable narrative-inspired moral philosophy, (...) of which Williams himself is perhaps the most impressive recent exponent. In the light of this apparent methodological confluence, Williams's disagreement with A about the meaning of Don Giovanni's final two scenes seems particularly significant. By offering an interpretation of Don Giovanni that both retains A's fundamental ideas and manages to get round the problems in Williams's account, I will show that the greatness of Mozart's opera is largely a function of the challenge it presents to the ‘morality system’. (shrink)

Modularity is a fundamental doctrine in the cognitive sciences. It holds a preeminent position in cognitive psychology and generative linguistics, as well as a long history in neurophysiology, with roots going all the way back to the early nineteenth century. But a mature field of neuroscience is a comparatively recent phenomenon and has challenged orthodox conceptions of the modular mind. One way of accommodating modularity within the new framework suggested by these developments is to go for increasingly soft versions of (...) modularity. One such version, which I call the “system” view, is so soft that it promises to meet practically any challenge neuroscience can throw at it. In this paper, I reconsider afresh what we ought to regard as the sine qua non of modularity and offer a few arguments against the view that an insipid “system” module could be the legitimate successor of the traditional notion. (shrink)