Vegetative State and Coma

Some patients, following brain injury, do not outwardly respond to spoken commands, yet show patterns of brain activity that indicate responsiveness. This is “cognitive-motor dissociation” (CMD). Recent research has used machine learning to diagnose CMD from electroencephalogram (EEG) recordings. These techniques have high false discovery rates, raising a serious problem of inductive risk. It is no solution to communicate the false discovery rates directly to the patient’s family, because this information may confuse, alarm and mislead. Instead, we need a procedure (...) for generating case-specific probabilistic assessments that can be communicated clearly. This article constructs a possible procedure with three key elements: (1) a shift from categorical “responding or not” assessments to degrees of evidence; (2) the use of patient-centred priors to convert degrees of evidence to probabilistic assessments; and (3) the use of standardized probability yardsticks to convey those assessments as clearly as possible. (shrink)

Can octopuses feel pain and pleasure? What about crabs, shrimps, insects, or spiders? How do we tell whether a person unresponsive after severe brain injury might be suffering? When does a fetus in the womb start to have conscious experiences? Could there even be rudimentary feelings in miniature models of the human brain, grown from human stem cells? And what about AI? These are questions about the edge of sentience, and they are subject to enormous, disorienting uncertainty. The stakes are (...) immense, and neglecting the risks can have terrible costs. We need to err on the side of caution, yet it’s often far from clear what ‘erring on the side of caution’ should mean in practice. When are we going too far? When are we not doing enough? The Edge of Sentience presents a comprehensive precautionary framework designed to help us reach ethically sound, evidence-based decisions despite our uncertainty. (shrink)

This paper defends the persistence of the subjective or self-intimating dimension of experience in non-ordinary and pathological states of consciousness such as non-dual awareness, full absorption, drug-induced ego dissolution, and the minimal conscious state. In considering whether non-ordinary and pathological conscious states display any subjective features, we confront a dilemma. Either they do, in which case there needs to be some way of accounting for these features in phenomenal terms, or they do not, in which case there is nothing it (...) is like to be in them. But the dilemma only arises if we assume that opacity rather than phenomenality is a pervasive feature of these non-ordinary states. However, non-ordinary conscious states are deemed phenomenally opaque only by overly restrictive standards of conceivability that: (i) fail to account for the variety of nonordinary and pathological experience in non-arbitrary ways; (ii) sidestep the problem of the attribution and location of mental content (given intelligibility requirements for experience) or relegate them to illusory constructs; (iii) assume an unproblematic appeal to testimonial evidence. I discuss some cases from contemplative traditions and psychopathology and offer some plausible alternative explanations. (shrink)

Animalism is prima facie the most plausible view about what we are; it aligns better with science and common sense, and is metaphysically more parsimonious. Thought experiments involving the brain, however, tend to elicit intuitions contrary to animalism. In this paper, I examine two classical thought experiments from the literature, brain transplant and cerebrum transplant, and a new one, cerebrum regeneration. I argue that they are theoretically possible, but that a scientifically informed account of what would actually happen shows that (...) in none of the cases would the person be separated from the animal. Our intuitions in these cases, when adequately informed by neuroscience, do not conflict with animalism – rather, they suggest a correction of the animalist position: the persisting animal should be at least minimally sentient. Sentience animalism is a new formulation of the animalist account of personal identity that allows us to reconcile facts about our biological persistence conditions with the intuition that human persistence should involve some kind of psychological continuity. (shrink)

Mackenzie Graham has made an important contribution to the literature on decisionmaking for patients with disorders of consciousness. He argues, and I agree, that decisions for unresponsive patients who are known to retain some degree of covert awareness ought to focus on current interests, since such patients likely retain the kinds of mental capacities that in ordinary life command our current respect and attention. If he is right, then it is not appropriate to make decisions for such patients by appealing (...) to the values they had in the past, either the values expressed in an advance directive or the values recalled by a surrogate. There are two things I wish to add to the discussion. My first point is somewhat critical, for although I agree with his general conclusion about how, ideally, such decisions should be approached, I remain skeptical about whether his conclusion offers decisionmakers real practical help. The problem with these cases is that the evidence we have about the nature of the patient’s current interests is minimal or nonexistent. However—and this is important—Graham’s conclusion will be extremely relevant if in the future, our ability to communicate with such patients improves, as I hope it will. This leads to my second point. Graham’s conclusion illustrates a more general problem with our standard framework for decisionmaking for previously competent patients, a problem that has not been adequately recognized. So, in what follows, I explain the problem I see and offer some brief thoughts about solutions. (shrink)

Aim: To elicit preferences for prognostic information, attitudes towards withdrawal of life-sustaining treatment (WLST) and perspectives on acceptable quality of life after post-anoxic coma within the adult general population of Germany, Italy, the Netherlands and the United States of America. Methods: A web-based survey, consisting of questions on respondent characteristics, perspectives on quality of life, communication of prognostic information, and withdrawal of life-sustaining treatment, was taken by adult respondents recruited from four countries. Statistical analysis included descriptive analysis and chi2-tests for (...) dierences between countries. Results: In total, 2012 respondents completed the survey. In each country, at least 84% indicated they would prefer to receive early prognostic information. If a poor outcome was predicted with some uncertainty, 37-54% of the respondents indicated that WLST was not to be allowed. A conscious state with severe physical and cognitive impairments was perceived as acceptable quality of life by 17–44% of the respondents. Clear differences between countries exist, including respondents from the U.S. being more likely to allow WLST than respondents from Germany (OR = 1.99, p < 0.001) or the Netherlands (OR = 1.74, p < 0.001) and preferring to stay alive in a conscious state with severe physical and cognitive impairments more than respondents from Italy (OR = 3.76, p < 0.001), Germany (OR = 2.21, p < 0.001), or the Netherlands (OR = 2.39, p < 0.001). Conclusions: Over one-third of the respondents considered WLST unacceptable when there is any remaining prognostic uncertainty. Respondents had a more positive perspective on acceptable quality of life after coma than what is currently considered acceptable in medical literature. This indicates a need for a closer look at the practice of WLST based on prognostic information, to ensure responsible use of novel prognostic tests. (shrink)

意識是如此不可捉摸又抽象的概念，「測量」意識簡直就像科幻小說情節。科學家近年來在這方面已大有進展，藉由各項腦造影技術和實驗手法，能夠分析不同意識狀態下的大腦活動型態。.

I consider the current best interests of patients who were once thought to be either completely unaware (to be in PVS) or only minimally aware (MCS), but who, because of advanced fMRI studies, we now suspect have much more “going on” inside their minds, despite no ability to communicate with the world. My goal in this chapter is twofold: (1) to set out and defend a framework that I think should always guide thinking about the best interests of highly cognitively (...) compromised patients, and then (2) to defend a particular conclusion that applies to this specific patient population. The framework requires us to ask two questions: Is the individual suffering? Is the individual gaining any benefit from life? There must be benefit of some sort for life to be worth preserving, and the benefit must outweigh any suffering (if there is suffering present). I then argue it would be best overall to allow these patients to die. Either these patients are not really very aware at all, in which case they are most likely not suffering, but not benefiting from life either, or they are mentally intact enough to make benefit a theoretical possibility, but in fact they are not benefiting because they cannot communicate with anyone. Such patients would most likely suffer. As there is no way currently to address their suffering, we should allow them to die. No matter the truth about their cognitive lives, death would either be a neutral event, or a blessing. (shrink)

Bioethics, neuroscience, medicine are contributing to a debate on the definition and criteria of death. This topic is very controversial, and it demonstrates clashing views on the meaning of human life and death. Official medical and legal positions agree upon a biological definition of death as irreversible cessation of integrated functioning of the organism as a whole, and whole-brain criterion to ascertain death. These positions have to face many criticisms: some scholars speak of logical and practical inconsistency, some others of (...) invalid scientific theory about the supreme integrator. In this paper some criticisms are exposed and discussed in order to reconstruct the state of the art in bioethical debate. -/- . (shrink)

Disorders of consciousness (DoC)—that is, unresponsive wakefulness syndrome/vegetative state and minimally conscious state—are debilitating conditions for which no reliable markers of consciousness recovery have yet been identified. Evidence points to the GABAergic system being altered in DoC, making it a potential target as such a marker.

After severe brain injury, one of the key challenges for medical doctors is to determine the patient’s prognosis. Who will do well? Who will not do well? Physicians need to know this, and families need to do this too, to address choices regarding the continuation of life supporting therapies. However, current prognostication methods are insufficient to provide a reliable prognosis. -/- Functional Magnetic Resonance Imaging (MRI) holds considerable promise for improving the accuracy of prognosis in acute brain injury patients. Nonetheless, (...) research on functional MRI in the intensive care unit context is ethically challenging. These studies raise several ethical issues that have not been addressed so far. In this article, Prof. Charles Weijer and his co-workers provide a framework for researchers and ethics committees to design and review these studies in an ethically sound way. (shrink)

Badania przy użyciu rezonansu magnetycznego sugerują, że przynajmniej niektórzy pacjenci w tzw. stanie wegetatywnym mogą być bardziej „świadomi”, niż to się do tej pory wydawało. W artykule zamierzam omówić te badania; następnie rozważę, o jakie rozumienie pojęcia świadomości może w nich chodzić; a wreszcie zastanowię się nad etycznymi implikacjami tych odkryć. Zamierzam też rozważyć, czy posiadanie wyższych form świadomości zawsze ma być dodatkową racją przemawiającą przeciwko zaprzestaniu podtrzymywaniu funkcji życiowych. Tym samym, w artykule chciałbym wskazać istotność badań z zakresu kognitywistyki (...) dotyczących pojęcia świadomości dla etycznej oceny pewnych praktyk medycznych. (shrink)

Consciousness in experimental subjects is typically inferred from reports and other forms of voluntary behaviour. A wealth of everyday experience confirms that healthy subjects do not ordinarily behave in these ways unless they are conscious. Investigation of consciousness in vegetative state patients has been based on the search for neural evidence that such broad functional capacities are preserved in some vegetative state patients. We call this the standard approach. To date, the results of the standard approach have suggested that some (...) vegetative state patients might indeed be conscious, although they fall short of being demonstrative. The fact that some vegetative state patients show evidence of consciousness according to the standard approach is remarkable, for the standard approach to consciousness is rather conservative, and leaves open the pressing question of how to ascertain whether patients who fail such tests are conscious or not. We argue for a cluster-based ‘natural kind’ methodology that is adequate to that task, both as a replacement for the approach that currently informs research into the presence or absence of consciousness in vegetative state patients and as a methodology for the science of consciousness more generally. 1. Introduction2. The Vegetative State3. The Standard Approach4. The Natural Kind Methodology5. Is Consciousness a Special Case? 5.1 Is consciousness a natural kind?5.2 A special obstacle?6. Conclusion. (shrink)

Disorders of consciousness include coma, the vegetative state and the minimally conscious state. Such patients are often regarded as unconscious. This has consequences for end of life decisions for these patients: it is much easier to justify withdrawing life support for unconscious than conscious patients. Recent brain imaging research has however suggested that some patients may in fact be conscious.

Recent work in neuroimaging suggests that some patients diagnosed as being in the persistent vegetative state are actually conscious. In this paper, we critically examine this new evidence. We argue that though it remains open to alternative interpretations, it strongly suggests the presence of consciousness in some patients. However, we argue that its ethical significance is less than many people seem to think. There are several different kinds of consciousness, and though all kinds of consciousness have some ethical significance, different (...) kinds underwrite different kinds of moral value. Demonstrating that patients have phenomenal consciousness — conscious states with some kind of qualitative feel to them — shows that they are moral patients, whose welfare must be taken into consideration. But only if they are subjects of a sophisticated kind of access consciousness — where access consciousness entails global availability of information to cognitive systems — are they persons, in the technical sense of the word employed by philosophers. In this sense, being a person is having the full moral status of ordinary human beings. We call for further research which might settle whether patients who manifest signs of consciousness possess the sophisticated kind of access consciousness required for personhood. (shrink)

I argue that a version of Pascal's Wager applies to the persistent vegetative state with sufficient force that it ought to part of advance directives.