This paper, presented as the 2019 Cambridge Quarterly Neuroethics Network Charcot Lecture, traces the nosology of disorders of consciousness in light of 2018 practice guidelines promulgated by the American Academy of Neurology, the American College of Rehabilitation Medicine and the National Institute on Disability, Independent Living and Rehabilitation Research. By exploring the ancient origins of Jennett and Plum’s persistent vegetative state and subsequent refinements in the classification of disorders of consciousness—epitomized by the minimally conscious state, cognitive motor dissociation, and the recently described chronic vegetative state—the author argues that there is a counter-narrative to the one linking these conditions to the right to die. Instead, there is a more nuanced schema distinguishing futility from utility, informed by technical advances now able to identify covert consciousness contemplated by Jennett and Plum. Their prescience foreshadows recent developments in the disorders of consciousness literature yielding a layered legacy with implications for society’s normative and legal obligations to these patients.

Long-term patient outcomes after severe brain injury are highly variable, and reliable prognostic indicators are urgently needed to guide treatment decisions. Functional neuroimaging is a highly sensitive method of uncovering covert cognition and awareness in patients with prolonged disorders of consciousness, and there has been increased interest in using it as a research tool in acutely brain injured patients. When covert awareness is detected in a research context, this may impact surrogate decisionmaking—including decisions about life-sustaining treatment—even though the prognostic value of covert consciousness is currently unknown. This paper provides guidance to clinicians and families in incorporating individual research results of unknown prognostic value into surrogate decisionmaking, focusing on three potential issues: (1) Surrogate decisionmakers may misinterpret results; (2) Results may create false hope about the prospects of recovery; (3) There may be disagreement about the meaningfulness or relevance of results, and appropriateness of continued care.

Disturbing cases continue to be published of patients declared brain dead who later were found to have a few intact brain functions. We address the reasons for the mismatch between the whole-brain criterion and brain death tests, and suggest solutions. Many of the cases result from diagnostic errors in brain death determination. Others probably result from a tiny amount of residual blood flow to the brain despite intracranial circulatory arrest. Strategies to lessen the mismatch include improving brain death determination training for physicians, mandating a test showing complete intracranial circulatory arrest, or revising the whole-brain criterion.

Neuroprosthetic speech devices are an emerging technology that can offer the possibility of communication to those who are unable to speak. Patients with ‘locked in syndrome,’ aphasia, or other such pathologies can use covert speech—vividly imagining saying something without actual vocalization—to trigger neural controlled systems capable of synthesizing the speech they would have spoken, but for their impairment.

We provide an analysis of the mechanisms and outputs involved in speech mediated by neuroprosthetic devices. This analysis provides a framework for accounting for the ethical significance of accuracy, control, and pragmatic dimensions of prosthesis-mediated speech. We first examine what it means for the output of the device to be accurate, drawing a distinction between technical accuracy on the one hand and semantic accuracy on the other. These are conceptual notions of accuracy.

Both technical and semantic accuracy of the device will be necessary (but not yet sufficient) for the user to have sufficient control over the device. Sufficient control is an ethical consideration: we place high value on being able to express ourselves when we want and how we want. Sufficient control of a neural speech prosthesis requires that a speaker can reliably use their speech apparatus as they want to, and can expect their speech to authentically represent them. We draw a distinction between two relevant features which bear on the question of whether the user has sufficient control: voluntariness of the speech and the authenticity of the speech. These can come apart: the user might involuntarily produce an authentic output (perhaps revealing private thoughts) or might voluntarily produce an inauthentic output (e.g., when the output is not semantically accurate). Finally, we consider the role of the interlocutor in interpreting the content and purpose of the communication.

These three ethical dimensions raise philosophical questions about the nature of speech, the level of control required for communicative accuracy, and the nature of ‘accuracy’ with respect to both natural and prosthesis-mediated speech.

The question as to whether people with an addiction have control (and to what extent) over their addiction, and voluntarily decide to use substances is an ongoing source of controversy in the context of research on addiction, health policy and clinical practice. We describe and discuss a set of five challenges for further research into voluntariness (definition[s], measurement and study tools, first person perspectives, contextual understandings, and connections to broader frameworks) based on our own research experiences and those of others.

Since the advent of recombinant DNA technology, expectations (and trepidations) about the potential for altering genes and controlling our biology at the fundamental level have been sky high. These expectations have gone largely unfulfilled. But though the dream (or nightmare) of being able to control our biology is still far off, gene editing research has made enormous strides toward potential clinical use. This paper argues that when it comes to determining permissible uses of gene editing in one important medical context—germline intervention in reproductive medicine—issues about enhancement and eugenics are, for the foreseeable future, a red herring. Current translational goals for gene editing research involve a different kind of editing than would be required to achieve manipulation of complex traits such as intelligence, and there are more pressing (and unresolved) questions that need attention if clinical use of gene editing in reproductive medicine ever becomes a possibility.

The microbiome is proving to be increasingly important for human brain functioning. A series of recent studies have shown that the microbiome influences the central nervous system in various ways, and consequently acts on the psychological well-being of the individual by mediating, among others, the reactions of stress and anxiety. From a specifically neuroethical point of view, according to some scholars, the particular composition of the microbiome—qua microbial community—can have consequences on the traditional idea of human individuality. Another neuroethical aspect concerns the reception of this new knowledge in relation to clinical applications. In fact, attention to the balance of the microbiome—which includes eating behavior, the use of psychobiotics and, in the treatment of certain diseases, the use of fecal microbiota transplantation—may be limited or even prevented by a biased negative attitude. This attitude derives from a prejudice related to everything that has to do with the organic processing of food and, in general, with the human stomach and intestine: the latter have traditionally been regarded as low, dirty, contaminated and opposed to what belongs to the mind and the brain. This biased attitude can lead one to fail to adequately consider the new anthropological conceptions related to the microbiome, resulting in a state of health, both physical and psychological, inferior to what one might have by paying the right attention to the knowledge available today. Shifting from the ubiquitous high-low metaphor (which is synonymous with superior-inferior) to an inside-outside metaphor can thus be a neuroethical strategy to achieve a new and unbiased reception of the discoveries related to the microbiome.

In this paper, the author argues that Joseph Fins’ mosaic decisionmaking model for brain-injured patients is untenable. He supports this claim by identifying three problems with mosaic decisionmaking. First, that it is unclear whether a mosaic is a conceptually adequate metaphor for a decisionmaking process that is intended to promote patient autonomy. Second, that the proposed legal framework for mosaic decisionmaking is inappropriate. Third, that it is unclear how we ought to select patients for participation in mosaic decisionmaking.

For individuals whose mental illness impair their ability to accept appropriate care—the depressed, acutely suicidal mother, or the psychotic lawyer too paranoid to eat any food—statutes exist to permit involuntary hospitalization, a temporary override of paternalistic benefice over personal autonomy. This exception to the primacy of personal autonomy at the core of bioethics has the aim of restoring the mental health of the temporarily incapacitated individual, and with it, their autonomy.