When we consider some controversies among scholars about whether brainstem death is death, we should clearly identify what the controversy is about. Is it about whether the brainstem dead can be ca...

Ariane Lewis provided an insightful review of several controversial cases of death by neurologic criteria (“brain death”) in the UK, focusing on Archie Battersbee, a boy whose tragic illness provok...

In The Human Animal I argued that we are animals, and that those animals do not persist by virtue of any sort of psychological continuity. Rather, personal identity in this sense consists in having the same biological life. And I said that a human life requires a functioning brainstem. Rina Tzinman takes this and other remarks to imply that personal identity consists in the continued functioning of the brainstem, which looks clearly false. I say it doesn’t follow. But (...) Alan Shewmon appears to have refuted my claim about the brainstem. (shrink)

Developmental coordination disorder is a neurodevelopmental disorder that significantly impairs a child’s ability to learn motor skills and to perform everyday activities. The cause of DCD is unknown; however, evidence suggests that children with DCD have altered brain structure and function. While the cerebellum has been hypothesised to be involved in developmental coordination disorder, no studies have specifically examined cerebellar structure in this population. The purpose of our study was to examine cerebellar differences in children with DCD compared to typically-developing (...) children. Using voxel-based morphometry, we assessed cerebellar morphology in children 8–12 years of age. Forty-six children were investigated using high resolution T1-weighted images, which were then processed using the spatially unbiased atlas template of the cerebellum and brainstem toolbox for a region of interest-based examination of the cerebellum. Results revealed that children with DCD had reduced grey matter volume in several regions, namely: the brainstem, right/left crus I, right crus II, left VI, right VIIb, and right VIIIa lobules. Further, Pearson correlations revealed significant positive associations between the total motor percentile score on the Movement Assessment Battery for Children-2 and regions that had reduced grey matter volume in our cohort. These findings indicate that reductions in cerebellar grey matter volume are associated with poorer motor skills. Given the cerebellum’s involvement in internal models of movement, results of this study may help to explain why children with DCD struggle to learn motor skills. (shrink)

Some patients who have been diagnosed as “dead by neurologic criteria” continue to exhibit certain brain functions, most commonly, neuroendocrine functions. This preservation of neurologic function after the diagnosis of “brain death” or “brainstem death” is an ongoing source of controversy and concern in the medical, bioethics, and legal literatures. Most obviously, if some brain function persists, then it is not the case that all functions of the entire brain have ceased and hence, declaring such a patient to be (...) “dead” would be a false positive, in any nation with so-called “whole brain death” laws. Furthermore, and perhaps more concerning, the preservation of any brain function necessarily entails the preservation of some amount of brain perfusion, thereby raising the concern as to whether additional areas of neural tissue may remain viable, including areas in the brainstem. These and other considerations cast significant doubt on the reliability of diagnosing either “brain death” or “brainstem death.”. (shrink)

This paper examines the development of the concept of brain death and of the criteria necessary for its recognition. Competing formulations of brain death are assessed and the case for a ‘brainstem’ concept of death is argued. Attention is finally drawn to some of the ethical issues raised by the use of neurological criteria in the diagnosis of human death.

This paper examines the development of the concept of brain death and of the criteria necessary for its recognition. Competing formulations of brain death are assessed and the case for a ‘brainstem’ concept of death is argued. Attention is finally drawn to some of the ethical issues raised by the use of neurological criteria in the diagnosis of human death.

Doubtless, the conscious brain integrates masses of information. But declaring that consciousness simply “emerges” when enough has accumulated, doesn't really explain how first person experience is implemented by neurons. Moreover, empirical observations challenge integrated information theory's (IIT) reliance on thalamo–cortical interactions as the information integrator. More likely, the cortex streams processed information to a still-enigmatic consciousness generator, one perhaps located in the brainstem.

Merker offers a remarkable statement about the neural integration essential to conscious states provided by the mesodiencephalon. The model for triangular interaction between action selection, target selection, and emotion is heuristic. Unfortunately, there is little interest (relatively speaking) in neuroscience in the mesodiencephalon, and attention is currently heavily directed to the telencephalon. This suggests that there may be less real momentum than commonly assumed towards the Holy Grail of neuroscience, a scientific theory of mind, despite the major upsurge in interest. (...) (Published Online May 1 2007). (shrink)

The self/non-self distinction is essential for survival, but its neural bases are poorly understood. Studies have sought neural specificity for 'self ' in cortical regions. However, behavioural evidence showing that humans are able to single out self-relevant information in the absence of awareness suggests that the cognitive self/non-self distinction might be rooted in subcortical structures involved in automatic, unconscious functions. Here we employ subliminal presentation of self and non-self faces and repetition suppression to show neural specificity for 'self ' in (...) the brainstem reticular formation, providing the first evidence for self/non-self distinction in subcortical structures. Our finding suggests that the brainstem may act as a neural substrate for the sense of 'self '. (shrink)

We thank the authors of commentaries for their thoughtful discussion of our target article. Here we briefly summarize the points made in the target article (Nair-Collins and Joffe 2023). Then we em...

The paradigmatic assumption that REM sleep is the physiological equivalent of dreaming is in need of fundamental revision. A mounting body of evidence suggests that dreaming and REM sleep are dissociable states, and that dreaming is controlled by forebrain mechanisms. Recent neuropsychological, radiological, and pharmacological findings suggest that the cholinergic brain stem mechanisms that control the REM state can only generate the psychological phenomena of dreaming through the mediation of a second, probably dopaminergic, forebrain mechanism. The latter mechanism (and thus (...) dreaming itself) can also be activated by a variety of nonREM triggers. Dreaming can be manipulated by dopamine agonists and antagonists with no concomitant change in REM frequency, duration, and density. Dreaming can also be induced by focal forebrain stimulation and by complex partial (forebrain) seizures during nonREM sleep, when the involvement of brainstem REM mechanisms is precluded. Likewise, dreaming is obliterated by focal lesions along a specific (probably dopaminergic) forebrain pathway, and these lesions do not have any appreciable effects on REM frequency, duration, and density. These findings suggest that the forebrain mechanism in question is the final common path to dreaming and that the brainstem oscillator that controls the REM state is just one of the many arousal triggers that can activate this forebrain mechanism. The “REM-on” mechanism (like its various NREM equivalents) therefore stands outside the dream process itself, which is mediated by an independent, forebrain “dream-on” mechanism. Key Words: acetylcholine; brainstem; dopamine; dreaming; forebrain; NREM; REM; sleep. (shrink)

It would be unwise to dismiss the possibility of human brain organoids developing sentience. However, scepticism about this idea is appropriate when considering current organoids. It is a point of consensus that a brainstem-dead human is not sentient, and current organoids lack a functioning brainstem. There are nonetheless troubling early warning signs, suggesting organoid research may create forms of sentience in the near future. To err on the side of caution, researchers with very different views about the neural (...) basis of sentience should unite behind the “brainstem rule”: if a neural organoid develops or innervates a functioning brainstem that registers and prioritizes its needs, regulates arousal, and leads to sleep-wake cycles, then it is a sentience candidate. If organoid research leads to the creation of sentience candidates, a moratorium or indefinite ban on the creation of the relevant type of organoid may be appropriate. A different way forward, more consistent with existing approaches to animal research, would be to require ethical review and harm-benefit analysis for all research on sentience candidates. (shrink)

The sudden infant death syndrome (SIDS) is the sudden, unexpected death of an infant that is not explained by autopsy, death scene examination, and history. The etiology is unknown. Recent postmortem studies have discovered abnormalities in brainstem serotonergic neurons, but how these translate into dysfunction and cause SIDS is uncertain. Recently, lethal effects in transgenic mice with overexpression of the serotonin 1A autoreceptor have been described. Many die spontaneously between postnatal day 40 (P40) and P80, and some spontaneously exhibit (...) bradycardias and drops in body temperature. The severity of the autonomic dysfunction and its age dependence suggest relevance to SIDS. However, SIDS cases have decreased serotonin 1A autoreceptor binding, which is opposite to its overexpression in the mice, and the peak incidence of SIDS is between 2 and 6 months of age, which is arguably younger (in relative terms) than the ages at which the mice die. Nevertheless, the description of an animal model with serotonin defects that has autonomic dysfunction and spontaneous mortality at a young age is an exciting finding of possible importance for understanding SIDS. (shrink)

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)

Treatment of diseases of the brain by drugs or surgery necessitates an understanding of its structure and functions. The philosophical neurosurgeon soon encounters difficulties when localising the abstract concepts of mind and soul within the tangible 1300-gram organ containing 100 billion neurones. Hippocrates had focused attention on the brain as the seat of the mind. The tabula rasa postulated by Aristotle cannot be localised to a particular part of the brain with the confidence that we can localise spoken speech to (...) Broca's area or the movement of limbs to the contralateral motor cortex. Galen's localisation of imagination, reasoning, judgement and memory in the cerebral ventricles collapsed once it was evident that the functional units-neurones-lay in the parenchyma of the brain. Experiences gained from accidental injuries (Phineas Gage) or temporal lobe resection (William Beecher Scoville); studies on how we see and hear and more recent data from functional magnetic resonance studies have made us aware of the extensive network of neurones in the cerebral hemispheres that subserve the functions of the mind. The soul or atman, credited with the ability to enliven the body, was located by ancient anatomists and philosophers in the lungs or heart, in the pineal gland (Descartes), and generally in the brain. When the deeper parts of the brain came within the reach of neurosurgeons, the brainstem proved exceptionally delicate and vulnerable. The concept of brain death after irreversible damage to it has made all of us aware of 'the cocktail of brain soup and spark' in the brainstem so necessary for life. If there be a soul in each of us, surely, it is enshrined here. (shrink)

For hundreds of years, death had been defined by cardiopulmonary criteria. When heart and respiratory functions were permanently absent, doctors declared their patients dead. Three developments in intensive care medicine called into question these widely-accepted criteria, however: the advent of positive pressure ventilation and the promotion of cardiopulmonary resuscitation, both in the early 1950s, and the first successful heart transplantation in 1967. What had previously been diagnosed as the permanent absence of vital functions, suddenly became reversible. Not only could doctors (...) replace a defective heart with a functioning transplant; patients could also be kept oxygenated in the total absence of spontaneous respiratory function. The traditional boundaries between life and death became blurred. Patients for whom there was not the remotest possibility of regaining consciousness following massive brain damage continued to consume valuable medical resources. Moreover, their organs could not be procured for transplantation. Were those patients still alive or could the ventilators be switched off? A criterion suited to indicate a patient’s death despite the provision of external life support was needed. In 1968 an ad hoc committee of the Harvard Medical School published the first comprehensive definition of what would soon become the new clinical standard: brain death. The brain bears a special relation to other organs; it directs bodily functions without carrying them out. When the brain is destroyed, it was argued, this control mechanism is irreversibly dysfunctional, so that the organism becomes unable to maintain its vital functions, loses its somatic unity and, consequently, ceases to exist. This neurological criterion has been controversial ever since its introduction. Whether brain death is indeed death is what I shall be investigating in this thesis. I will be asking three main questions: What are we? Is brain death the death of an organism? Is brain death the death of a psychological being? The question of personal identity and the question of the appropriate definition of death are intimately related. Only when we have determined what kind of entity we essentially are can we specify what conditions must apply for this entity to persist or to cease to exist. I shall argue that we are essentially psychological beings, which entails that our death is distinct from the death of our organisms. Hence, we need two different criteria – one for the death of each entity. I shall try to establish whether brainstem death and whole-brain death correspond to the irreversible cessation of organismic functioning. I will then determine by which criterion the death of a psychological being can be diagnosed. (shrink)

In 1968 the authors of the so-called Harvard Report, proposed the recognition of an irreversible coma as a new criterion for death. The proposal was accepted by the medical, legal, religious and political circles in spite of the lack of any explanation why the irreversible coma combined with the absence of brainstem reflexes, including the respiratory reflex might be equated to death. Such an explanation was formulated in the President’s Commission Report published in 1981. This document stated, that the (...) brain is the central integrator of the body, therefore the destruction of the brain results in the lack of that integration and the death of the organism. Therefore, according to that document, the so-called “brain dead” patients are really, biologically dead; strictly speaking they are not any more biological organisms but collections of organs and tissues. Their death was masked by the use of the medical equipment, but it was a real, biological death. Thus, the explanation given by the President’s Commission Report constituted a biological rationale for the new concept of death, known as “brain death.” However, after the long discussion, this rationale was refuted because of the evidence given by many medical authorities, that the bodies of the “brain dead” and “brainstem dead” patients are alive. In the context of the discussion about the neurological criteria for death, some authors follow the idea of Plato, that human being is the soul or mind, and the body does not belong to the human essence. Therefore, the loss of consciousness, which may be identified with the mind, constitutes the loss of personhood and may be interpreted as human death. The other group stresses the Aristotelian and Thomistic concept that the body belongs to the essence of every living creature, including human. Therefore, as long as the body is alive, the human being is alive and we cannot call the given patient dead even if he is deeply comatose. Moreover, in spite of the opinions dominating in the mass-media, these patients should be considered not only alive but also may be conscious to some degree and their state can be reversible. Their brains are lacking the electrical functions, but the neuronal tissue is alive and that state is reversible for at least first 48 hours since the onset of coma; this phenomenon is called “global ischemic penumbra” and is responsible for the regularly happening events interpreted as miracles, when some of the “brain dead” or “brainstem dead” patients turn to be alive and come back to normal life. Therefore, the neurological criteria of death are still lacking generally accepted scientific basis and should not be used in medicine and in the legal systems as a basis for diagnosing comatose/having no brainstem reflexes/apneic patients dead. (shrink)

feelings (brainstem, limbic system). The best scientific synchrony and consciousness.21,27 Anesthesiology, V 105, No 2, Aug 2006.

A broad range of evidence regarding the functional organization of the vertebrate brain – spanning from comparative neurology to experimental psychology and neurophysiology to clinical data – is reviewed for its bearing on conceptions of the neural organization of consciousness. A novel principle relating target selection, action selection, and motivation to one another, as a means to optimize integration for action in real time, is introduced. With its help, the principal macrosystems of the vertebrate brain can be seen to form (...) a centralized functional design in which an upper brain stem system organized for conscious function performs a penultimate step in action control. This upper brain stem system retained a key role throughout the evolutionary process by which an expanding forebrain – culminating in the cerebral cortex of mammals – came to serve as a medium for the elaboration of conscious contents. This highly conserved upper brainstem system, which extends from the roof of the midbrain to the basal diencephalon, integrates the massively parallel and distributed information capacity of the cerebral hemispheres into the limited-capacity, sequential mode of operation required for coherent behavior. It maintains special connective relations with cortical territories implicated in attentional and conscious functions, but is not rendered nonfunctional in the absence of cortical input. This helps explain the purposive, goal-directed behavior exhibited by mammals after experimental decortication, as well as the evidence that children born without a cortex are conscious. Taken together these circumstances suggest that brainstem mechanisms are integral to the constitution of the conscious state, and that an adequate account of neural mechanisms of conscious function cannot be confined to the thalamocortical complex alone. (Published Online May 1 2007) Key Words: action selection; anencephaly; central decision making; consciousness; control architectures; hydranencephaly; macrosystems; motivation; target selection; zona incerta. (shrink)

Any account of “what is special about the human brain” (Passingham 2008) must specify the neural basis of our unique ability to produce speech and delineate how these remarkable motor capabilities could have emerged in our hominin ancestors. Clinical data suggest that the basal ganglia provide a platform for the integration of primate-general mechanisms of acoustic communication with the faculty of articulate speech in humans. Furthermore, neurobiological and paleoanthropological data point at a two-stage model of the phylogenetic evolution of this (...) crucial prerequisite of spoken language: (i) monosynaptic refinement of the projections of motor cortex to the brainstem nuclei that steer laryngeal muscles, presumably, as part of a “phylogenetic trend” associated with increasing brain size during hominin evolution; (ii) subsequent vocal-laryngeal elaboration of cortico-basal ganglia circuitries, driven by human-specificFOXP2mutations.;>This concept implies vocal continuity of spoken language evolution at the motor level, elucidating the deep entrenchment of articulate speech into a “nonverbal matrix” (Ingold 1994), which is not accounted for by gestural-origin theories. Moreover, it provides a solution to the question for the adaptive value of the “first word” (Bickerton 2009) since even the earliest and most simple verbal utterances must have increased the versatility of vocal displays afforded by the preceding elaboration of monosynaptic corticobulbar tracts, giving rise to enhanced social cooperation and prestige. At the ontogenetic level, the proposed model assumes age-dependent interactions between the basal ganglia and their cortical targets, similar to vocal learning in some songbirds. In this view, the emergence of articulate speech builds on the “renaissance” of an ancient organizational principle and, hence, may represent an example of “evolutionary tinkering” (Jacob 1977). (shrink)

Discrepancies between the Uniform Determination of Death Act (UDDA) and the adult and pediatric diagnostic guidelines for brain death (BD) (the “Guidelines”) have motivated proposals to revise the UDDA. A revision proposed by Lewis, Bonnie and Pope (the RUDDA), has received particular attention, the three novelties of which would be: (1) to specify the Guidelines as the legally recognized “medical standard,” (2) to exclude hypothalamic function from the category of “brain function,” and (3) to authorize physicians to conduct an apnea (...) test without consent and even over a proxy’s objection. One hundred seven experts in medicine, bioethics, philosophy, and law, spanning a wide variety of perspectives, have come together in agreement that while the UDDA needs revision, the RUDDA is not the way to do it. Specifically, (1) the Guidelines have a non-negligible risk of false-positive error, (2) hypothalamic function is more relevant to the organism as a whole than any brainstem reflex, and (3) the apnea test carries a risk of precipitating BD in a non-BD patient, provides no benefit to the patient, does not reliably accomplish its intended purpose, and is not even absolutely necessary for diagnosing BD according to the internal logic of the Guidelines; it should at the very least require informed consent, as do many procedures that are much more beneficial and less risky. Finally, objections to a neurologic criterion of death are not based only on religious belief or ignorance. People have a right to not have a concept of death that experts vigorously debate imposed upon them against their judgment and conscience; any revision of the UDDA should therefore contain an opt-out clause for those who accept only a circulatory-respiratory criterion. (shrink)

The present study aims to examine the relationship between the cortical midline structures (CMS), which have been regarded to be associated with selfhood, and moral decision making processes at the neural level. Traditional moral psychological studies have suggested the role of moral self as the moderator of moral cognition, so activity of moral self would present at the neural level. The present study examined the interaction between the CMS and other moral-related regions by conducting psycho-physiological interaction analysis of functional images (...) acquired while 16 subjects were solving moral dilemmas. Furthermore, we performed Granger causality analysis to demonstrate the direction of influences between activities in the regions in moral decision-making. We first demonstrate there are significant positive interactions between two central CMS seed regions—i.e., the medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC)—and brain regions associated with moral functioning including the cerebellum, brainstem, midbrain, dorsolateral prefrontal cortex, orbitofrontal cortex and anterior insula (AI); on the other hand, the posterior insula (PI) showed significant negative interaction with the seed regions. Second, several significant Granger causality was found from CMS to insula regions particularly under the moral-personal condition. Furthermore, significant dominant influence from the AI to PI was reported. Moral psychological implications of these findings are discussed. The present study demonstrated the significant interaction and influence between the CMS and morality-related regions while subject were solving moral dilemmas. Given that, activity in the CMS is significantly involved in human moral functioning. (shrink)

Theories of superior collicular and hippocampal function have remarkable similarities. Both structures have been repeatedly implicated in spatial and attentional behaviour and in inhibitory control of locomotion. Moreover, they share certain electrophysiological properties in their single unit responses and in the synchronous appearance and disappearance of slow wave activity. Both are phylogenetically old and the colliculus projects strongly to brainstem nuclei instrumental in the generation of theta rhythm in the hippocampal EECOn the other hand, close inspection of behavioural and (...) electrophysiological data reveals disparities. In particular, hippocampal processing mainly concerns stimulus ambiguity, contextual significance, and spatial relations or other subtle, higher order characteristics. This requires the use of largely preprocessed sensory information and mediation of poststimulus investigation. Although collicular activity must also be integrated with that of “higher” centres, its primary role in attention is more “peripheral” and specific in controlling orienting/localisation via eye and body movements toward egocentrically labelled spatial positions. In addition, the colliculus may exert a nonspecific influence in alerting higher centres to the imminence of information potentially worthy of focal attention. Nevertheless, it is noteworthy that collicular and hippocampal lesions produce deficits on similar tasks, although the type of deficit is usually different in each case. Functional overlap between hippocampus and colliculus is virtually certain vis-à-vis stimulus sampling, for example in the acquisition of information via vibrissal movements and visual scanning. In addition, insofar as stimulus significance is a factor in collicular orienting mechanisms, the hippocampus — cingulate – cortex — colliculus pathway may play a significant role, modulating collicular responsiveness and thus ensuring an attentional strategy appropriate to current requirements. A tentative “reciprocal loop” model is proposed which bridges physiological and behavioural levels of analysis and which would account for the observed degree and nature of functional overlap between the superior colliculus and hippocampus. (shrink)

Does it matter that the hearts of 'brainstem dead' patients may persist in beating spontaneously? Hostile reactions, to the Danish inclusion of cardiac criteria in the determination of death, betray reductionist views of human life at the core of 'brainstem' conceptions of death. Such views (whether centred on neurological function or on abstractions concerning 'personhood') supplant the richness of human life and death with the poverty of essentialism: and mask the lethal nature of beating-heart organ retrieval. The affirmation (...) of cardiac criteria for death is not an alternative form of essentialism as some critics suppose, but part of an understanding of human life and death which rejects essentialism altogether. The spontaneously persistent heartbeat does not constitute human life, but most certainly counts for it. (shrink)

Although most aspects of world and self-consciousness are inherently subjective, neuroscience studies in humans and non-human animals provide correlational and causative indices of specific links between brain activity and representation of the self and the world. In this article we review neuroanatomic, neurophysiological and neuropsychological data supporting the hypothesis that different levels of self and world representation in vertebrates rely upon i) a 'basal' subcortical system that includes brainstem, hypothalamus and central thalamic nuclei and that may underpin the primary (...) (or anoetic) consciousness likely present in all vertebrates; and ii) a forebrain system that include the medial and lateral structures of the cerebral hemispheres and may sustain the most sophisticated forms of consciousness (e.g. noetic (knowledge based) and autonoetic, reflective knowledge). We posit a mutual, bidirectional functional influence between these two major brain circuits. We conclude that basic aspects of consciousness like primary self and core self (based on anoetic and noetic consciousness) are present in many species of vertebrates and that, even self-consciousness (autonoetic consciousness) does not seem to be a prerogative of humans and of some non-human primates but may, to a certain extent, be present in some other mammals and birds. (shrink)

In 1959 two French neurologists, Pierre Mollaret and Maurice Goullon, coined the term coma dépassé to designate a state beyond coma. In this state, patients are not only permanently unconscious; they lack the endogenous drive to breathe, as well as brainstem reflexes, indicating that most of their brain has ceased to function. Although legally recognized in many countries as a criterion for death, brain death has not been universally accepted by bioethicists, by the medical community, or by the public. (...) I this paper, I defend brain death as a biological concept. I challenge two assumptions in the brain death literature that have shaped the debate and have stood in the way of an argument for brain death as biological. First, I challenge the dualism established in the debate between the body and the brain. Second, I contest the emphasis on consciousness, which prevents the inclusion of psychological phenomena into a biological criterion of death. I propose that the term organism should apply both to the functioning of the body and the brain. I argue that the cessation of the organism as a whole should take into account three elements of integrated function. Those three elements are: 1) the loss of integrated bodily function; 2) the loss of psychophysical integration required for processing of external stimuli and those required for behavior; and, 3) the loss of integrated psychological function, such as memory, learning, attention, and so forth. The loss of those three elements of integrated function is death. (shrink)

For decades, physicians, philosophers, theologians, lawyers, and the public considered brain death a settled issue. However, a series of recent cases in which individuals were declared brain dead yet physiologically maintained for prolonged periods of time has challenged the status quo. This signals a need for deeper reflection and reexamination of the underlying philosophical, scientific, and clinical issues at stake in defining death. In this paper, I consider four levels of philosophical inquiry regarding death: the ontological basis, actual states of (...) affairs, epistemological standards, and clinical criteria for brain death. I outline several candidates for the states of affairs that may constitute death, arguing that we should strive for a single, unified ontological definition of death as a loss of integrated functioning as a unified organism, while acknowledging that two states of affairs may satisfy this concept. I argue that the clinical criteria for determining whole-brain death should be bolstered to meet the epistemic demand of sufficient certainty in defining death by adding indicators of cerebro-somatic dis-integration to the traditional triad of loss of consciousness, loss of brainstem function, and absence of confounding explanations. (shrink)

Baby A1 was born prematurely with severe encephalopathy, injured brainstem, and a potentially injured spinal cord. He had no response to pain or other external stimuli. The neonatal team unanimousl...

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)