Tube feedings and persistent vegetative state patients: ordinary or extraordinary means?

This article looks at the late John Paul II's allocution on artificial nutrition and hydration (ANH) and the implications his statement will have on the ordinary-extraordinary care distinction. The purpose of this article is threefold: first, to examine the medical condition of a persistent vegetative state (PVS); second, to examine and analyze the Catholic Church's tradition on the ordinary-extraordinary means distinction; and third, to analyze the ethics behind the pope's recent allocution in regards to PVS patients as a matter of conscience. Rather than providing clarification, I argue that the papal allocution has raised many difficult questions. People in situations where decisions must be made about withdrawal or continued ANH are in need of guidance. Moreover, additional analysis is needed to determine whether the papal allocution is in conflict with the traditional Catholic medical ethics understanding of the ordinary-extraordinary care distinction.     

The burdens-benefits ratio consideration for medical administration of nutrition and hydration to persons in the persistent vegetative state.

In this article, Harvey notes the initial confusion about the statement made by the pope concerning artificial nutrition and hydration on patients suffering persistent vegetative states (PVS) due to misunderstanding through the translation of the pope's words. He clarifies and assesses what was meant by the statement. He also discusses the problems of terminology concerned with the subject of PVS. Harvey concludes that the papal allocution was in line with traditional Catholic bioethics, and that while maintaining the life of a patient is favorable, in particular cases this presumption wanes when it is clear that this treatment modality would be futile or very burdensome.     

More dead than dead: perceptions of persons in the persistent vegetative state

Patients in persistent vegetative state (PVS) may be biologically alive, but these experiments indicate that people see PVS as a state curiously more dead than dead. Experiment 1 found that PVS patients were perceived to have less mental capacity than the dead. Experiment 2 explained this effect as an outgrowth of afterlife beliefs, and the tendency to focus on the bodies of PVS patients at the expense of their minds. Experiment 3 found that PVS is also perceived as “worse” than death: people deem early death better than being in PVS. These studies suggest that people perceive the minds of PVS patients as less valuable than those of the dead – ironically, this effect is especially robust for those high in religiosity.     

植物人研究中的一些神经心理学问题

自从Ｊｅｎｎｅｔｔ等提出＂持久的植物状态＂概念之后,有关植物人的问题已经引起中国医疗卫生界的广泛重视,并且在临床治疗方面取得了一定的成绩。该文对国内及国际植物人研究状况作了简要的评述．作者认为统一关于植物人定义的认识,研究植物人的病理生理机制以及确定临床观察的心理学定量指标乃是中国科学工作者当务之急。     

No effects of executive control depletion on prospective memory retrieval processes

Research has suggested that prospective memory retrieval is reliant on executive control processes, and the degree to which these processes are necessary for intention fulfillment is dependent on a host of variables related to the prospective memory task. Based on results suggesting that aspects of the prospective memory task vary in their need for executive control, the current study examined the possibility that executive control depletion from the Stroop task would negatively transfer to prospective memory performance. Depletion of executive control, measured objectively in a Stroop task, did not impair prospective memory performance in either low or high cue-target association conditions. However, participants’ subjective assessments of their own cognitive fatigue correlated significantly with their prospective memory performance, regardless of the association between cues and target responses.     

Persistent Vegetative State: A Presumption to Treat

The article briefly analyzes the concept of a person, arguing that personhood does not coincide with the actual enjoyment of certain intellectual capacities, but is coextensive with the embodiment of a human individual. Since in PVS patients we can observe a human individual functioning as a whole, we must conclude that these patients are still human persons, even if in a condition of extreme impairment. It is then argued that some forms of minimal treatment may not be futile for these patients; they may constitute a form of respect for their human dignity and benefit these patients, even if they are not aware of that. Moreover, it is important to consider the symbolic significance of care: while many believe that PVS is a kind of imprisonment, for others providing food and fluids is the only way to testify our proximity to these persons. The best policy would be to provide, as a general rule, artificial nutrition and hydration to PVS patients: this treatment could be withdrawn, after a period of observation and reflection by the family and proxies, on the basis of the proxies' objection to the continuation or of the patient's advance directives specifically referring to this situation.     

Persistent Vegetative State: Clinical and Ethical Issues

Coma, vegetative state, lock-in syndrome and akinetic mutism are defined. Vegetative state is a state with no evidence of awareness of self or environment and showing cycles of sleep and wakefulness. PVS is an operational definition including time as a variable. PVS is a vegetative state that has endured or continued for at least one month. PVS can be diagnosed with a reasonable amount of medical certainty; however, the diagnosis of PVS must be kept separate from the outcome. The patient outcome can be predicted based on etiology and age. Using outcome probabilities and etiology as criteria, patients can be subdivided in 5 groups and reasonable management guidelines can be suggested. Three levels of care can be provided to PVS patients: high technology, supportive and compassionate care. Pragmatic options for the various subgroups of patients are suggested. Management decisions will remain difficult for both the family and the health-care team. The role of the physician in these difficult cases is to share the decision-making with the family.     

Affordances and Prospective Control: An Outline of the Ontology

Actions must be controlled prospectively. This requires that the behavioral possibilities of surface layouts and events be perceived. In this article, the ontolog- ical basis for an understanding of prospective control in realist terms is outlined. The foundational idea is that of affordances and the promoted ontology is materialist and dynamicist. It is argued that research in the ecological approach to prospective control is ultimately the search for objective laws. Because lawfulness is equated with real possibility, this amounts to the study of the affordances (the real possibilities) underlying prospective control and the circumstances that actualize them. The ontological assumptions and hypotheses bearing on this latter proposal are articulated. It is suggested that critical evaluation of the identified ontological themes may benefit the experimental and theoretical study of perception in the service of activity.     

Does any aspect of mind survive brain damage that typically leads to a persistent vegetative state? Ethical considerations

Recent neuroscientific evidence brings into question the conclusion that all aspects of consciousness are gone in patients who have descended into a persistent vegetative state (PVS). Here we summarize the evidence from human brain imaging as well as neurological damage in animals and humans suggesting that some form of consciousness can survive brain damage that commonly causes PVS. We also raise the issue that neuroscientific evidence indicates that raw emotional feelings (primary-process affects) can exist without any cognitive awareness of those feelings. Likewise, the basic brain mechanisms for thirst and hunger exist in brain regions typically not damaged by PVS. If affective feelings can exist without cognitive awareness of those feelings, then it is possible that the instinctual emotional actions and pain "reflexes" often exhibited by PVS patients may indicate some level of mentality remaining in PVS patients. Indeed, it is possible such raw affective feelings are intensified when PVS patients are removed from life-supports. They may still experience a variety of primary-process affective states that could constitute forms of suffering. If so, withdrawal of life-support may violate the principle of nonmaleficence and be tantamount to inflicting inadvertent "cruel and unusual punishment" on patients whose potential distress, during the process of dying, needs to be considered in ethical decision-making about how such individuals should be treated, especially when their lives are ended by termination of life-supports. Medical wisdom may dictate the use of more rapid pharmacological forms of euthanasia that minimize distress than the de facto euthanasia of life-support termination that may lead to excruciating feelings of pure thirst and other negative affective feelings in the absence of any reflective awareness.     

Disability versus futility in rationing health care services: defining medical futility based on permanent unconsciousness--PVS,coma, and anencephaly

All societies must ration health care services in the face of unlimited demand. The concept of medical futility may appear to be an uncontroversial means by which to ration services. Depending upon how it is applied, however, limiting services based on alleged medical futility may violate prohibitions against disability-based discrimination. In particular, use of medical futility to require removal of life-sustaining interventions has been held to violate the Americans with Disabilities Act. The ADA protects both people with disabilities who are conscious and people in unconscious states, such as permanent vegetative state (PVS), coma, and anencephaly. Ultimately, as the number of people in permanently unconscious states increases, our society will have to recognize that consciousness is an essential characteristic defining human beings and determining whether a legal right to unlimited life-sustaining intervention should apply. This article proposes to define medical futility to preclude life-sustaining interventions after a stated period of permanent unconsciousness and to redefine the end of life consistently as neocortical death.     

对植物状态生存的理性思考

分析植物状态生存的判定和分类,从人的本质分析植物状态的生存价值,从生物学、社会学角度分析植物状态生存与死亡的区别与联系,认为植物人仅仅是生物学上的不完全生命状态,在社会学意义上,他是死亡个体。对我国卫生费用的现状进行评估,从医学、社会学和经济学角度对植物状态生存者维持或放弃治疗进行了理性分析。     

Abandon the dead donor rule or change the definition of death?

Research by Siminoff and colleagues reveals that many lay people in Ohio classify legally living persons in irreversible coma or persistent vegetative state (PVS) as dead that additional respondents, although classifying such patients as living, would be willing to procure organs from them. This paper analyzes possible implications of these findings for public policy. A majority would procure organs from those in irreversible coma or in PVS. Two strategies for legitimizing such procurement are suggested. One strategy would be to make exceptions to the dead donor rule permitting procurement from those in PVS or at least those who are in irreversible coma while continuing to classify them as living. Another strategy would be to further amend the definition of death to classify one or both groups as deceased, thus permitting procurement without violation of the dead donor rule. Permitting exceptions to the dead donor rule would require substantial changes in law--such as authorizing procuring surgeons to end the lives of patients by means of organ procurement--and would weaken societal prohibitions on killing. The paper suggests that it would be easier and less controversial to further amend the definition of death to classify those in irreversible coma and PVS as dead. Incorporation of a conscience clause to permit those whose religious or philosophical convictions support whole-brain or cardiac-based death pronouncement would avoid violating their beliefs while causing no more than minimal social problems. The paper questions whether those who would support an exception to the dead donor rule in these cases and those who would support a further amendment to the definition of death could reach agreement to adopt a public policy permitting organ procurement of those in irreversible coma or PVS when proper consent is obtained.     

前瞻性记忆的生理基础

中国科学院心理研究所,北京 100101     

On Categories and A Posteriori Necessity: A Phenomenological Echo

This article argues for two related theses. First, it defends a general thesis: any kind of necessity, including metaphysical necessity, can only be known a priori. Second, however, it also argues that the sort of a priori involved in modal metaphysical knowledge is not related to imagination or any sort of so‐called epistemic possibility. Imagination is neither a proof of possibility nor a limit to necessity. Rather, modal metaphysical knowledge is built on intuition of philosophical categories and the structures they form.     

Quick to Act,Quick to Forget: The Link Between Impulsiveness and Prospective Memory

Several traits of impulsiveness (e.g. lack of planning and perseverance, difficulty focusing attention) seem intimately connected to the skills required for successful prospective memory performance. This is the first study to examine whether the various inter‐correlated dimensions of impulsiveness are related to problems with prospective memory. Undergraduate students (N = 184) completed the Barratt Impulsiveness Scale 11, the Prospective Memory Questionnaire, the Prospective and Retrospective Memory Questionnaire, and two objective prospective memory tests. Results revealed consistent correlations between the various dimensions of impulsiveness (attentional, motor, non‐planning) and self‐reported problems with prospective memory. Subsequent regression analyses indicated that attentional impulsiveness is a unique predictor of self‐reported problems with internally cued prospective memory, and non‐planning impulsiveness is a unique predictor of self‐reported problems with episodic and overall prospective memory. Similarly, findings from the objective prospective tests showed that non‐planning impulsiveness was related to worse performance on the two prospective memory tests. Whereas non‐planning impulsiveness was also related to using fewer prospective memory‐aiding strategies, mediation analyses showed that use of these strategies does not account for any of the detected relationships. Because the findings suggest that a failure to plan does not underlie the detected effects, other potential explanations for the relationships are discussed. Copyright © 2013 European Association of Personality Psychology     

From “the Ethical Treatment of Patients in a Persistent Vegetative State” to a Philosophical Reflection on Contemporary Medicine

The reflections put forward in this text concern the clinical and practical difficulties posed by the existence of patients in PVS, and the essential ethical issues raised, combining these ethical questions with practical and theoretical experience. Section 1 presents the methodology of the ethical reflection as we see it. Section 2 describes the clinical condition of patients in PVS. Section 3 develops the ethical difficulties relative to PVS from the French point of view. Section 4 illustrates the relevance of debating the ethical significance of such problematic situations, whilst defending a practical position based on a philosophical conviction. Section 5 points out the limits of ethical reflection in a biomedical context, and calls for reflection closer to the source of the problems described. For a comprehensive appraisal of biomedical rationality, the final section suggests combining the bioethical debates with traditional philosophical ethical reflection so as to get a clearer understanding of the real, if limited, relevance of these debates.     

Family,peer, and neighborhood influences on academic achievement among African-American adolescents: One-year prospective effects

Using a 1-year prospective design, this study examined the influence of family status variables (family income, parental education, family structure), parenting variables (maternal support and restrictive control), peer support, and neighborhood risk on the school performance of 120 African American junior high school students. In addition to main effects of these variables, neighborhood risk was examined as a moderator of the effects of parenting and peer support. Family status variables were not predictive of adolescent school performance as indexed by self-reported grade point average. Maternal support at Time 1 was prospectively related to adolescent grades at Time 2. Neighborhood risk was related to lower grades, while peer support predicted better grades in the prospective analyses. Neighborhood risk also moderated the effects of maternal restrictive control and peer support on adolescent grades in prospective analyses. These findings highlight the importance of an ecological approach to the problem of academic underachievement within the African American community.     

Metamemory,distinctiveness, and event-related potentials in recognition memory for faces

A neglected topic in metamemory research is the ability of subjects to predict their own recognition performance for faces. We investigated whether subjects can make such judgments of learning (JOL) for unfamiliar faces and whether JOLs relate to facial distinctiveness, a powerful determinant of face recognition. One group of subjects made JOLs, and a second group rated the same faces for distinctiveness; subsequently, both groups tried to recognize these faces among new faces. There was significant prospective metamemory for faces that appeared to be based on facial distinctiveness. Both prospective metamemory and distinctiveness ratings related to long-lasting effects in event-related brain potentials (ERPs), closely resembling an ERP component that predicted face recognition. Therefore, the brain processes underlying JOLs, distinctiveness, and recognition memory for faces appear to be intimately related.     

Development,Ethics, and the Ethics of Development

This article investigates three things: (1) what development might be, (2) how development and ethics might be related, and (3) what an ethics of development might look like. First, I show how if we move away from an essentialist metaphysics of being to a possibilist-functionalist metaphysics of becoming in our understanding of development, we can reconceptualize ethics as self-directed ontogeny. Thus, ethics turns out to be a part of development. Secondly, I sketch out the possibility of an ethics of development, showing how it should be based on three desiderata: (1) sustainability, promoting the long-term existence of the maximum human and non-human biodiversity, (2) democracy, promoting human-human relationships that are bidirectional and, to the extent possible, non-imposing, and (3) non-ethnocentrism, promoting true modernity; a modernity not predicated on a non-existent abstract universality but on concrete syncretism. The ultimate aim of this ethics of development is the optimization of individual and collective subjectivity and agency across time.     

Innovations in computational type theory using Nuprl

For twenty years the Nuprl (“new pearl”) system has been used to develop software systems and formal theories of computational mathematics. It has also been used to explore and implement computational type theory (CTT)—a formal theory of computation closely related to Martin-Löf's intuitionistic type theory (ITT) and to the calculus of inductive constructions (CIC) implemented in the Coq prover.

This article focuses on the theory and practice underpinning our use of Nuprl for much of the last decade. We discuss innovative elements of type theory, including new type constructors such as unions and dependent intersections, our theory of classes, and our theory of event structures.

We also discuss the innovative architecture of Nuprl as a distributed system and as a transactional database of formal mathematics using the notion of abstract object identifiers. The database has led to an independent project called the Formal Digital Library, FDL, now used as a repository for Nuprl results as well as selected results from HOL, MetaPRL, and PVS. We discuss Howe's set theoretic semantics that is used to relate such disparate theories and systems as those represented by these provers.