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This chapter discusses the metaphysical and ethical implications of severe brain injury, considering the respects in which individuals with these injuries survive or fail to survive them. It underscores the difficulty in diagnosing disorders of consciousness. Even when individuals survive brain injuries, they may or may not benefit from medical interventions that keep them alive and restore a greater degree of consciousness. Survival and consciousness by themselves have no value. What matters is which physical and cognitive functions are restored, the degree to which they are restored, and how they compare with the functions the individual had before the injury. In some cases, recovering a greater degree of consciousness can be worse for a person and result in significant harm.

This chapter evaluates the tenability of the unity thesis by examining the evidence for phenomenal disunity within the context of number of quite different domains. The first third of the chapter addresses the question of whether the unity of consciousness might break-down in the context of the perceptual phenomena of apparent motion and meta‐contrast masking. The second third of the chapter examines objections to the unity thesis that appeal to data derived from studies drawn from developmental psychology. The final third of the chapter evaluates objections to the unity thesis derived from a cluster of conditions that are characterized by minimal responsiveness: the persistent vegetative state, the minimally conscious state, and epileptic fugue states. It is argued that none of these objections undermines the unity thesis.

In recent years, rapid technological developments in the field of neuroimaging have provided new methods for revealing thoughts, actions and intentions based solely on the pattern of activity that is observed in the brain. In specialized centres, these methods are now being employed routinely in the assessment of patients diagnosed with so-called ‘disorders of consciousness’, mapping patterns of residual function and dysfunction and helping to reduce diagnostic errors between related conditions such as the vegetative and minimally conscious states. In some cases, functional neuroimaging has even been used to detect covert awareness in behaviourally non-responsive patients when standard clinical techniques have been unable to provide that information. In this chapter, those circumstances in which functional neuroimaging data can be used to infer awareness in the absence of a behavioural response will be contrasted with those circumstances in which it cannot. This distinction is fundamental for understanding and interpreting patterns of brain ‘activation’ following acute brain injury.

Disorders of consciousness are devastating to patients and present profound challenges to clinicians, scientists, philosophers, and ethicists alike. In the past, distinguishing between levels of these disorders has been vital to guiding important decisions. This chapter argues that these disorders are not sufficiently distinct, however, to dictate such decisions: diagnostic criteria are not discrete, nor do they reflect the conceptual definitions of these disorders. It argues that these non-distinct diagnostic boundaries reflect an inherent continuity between disorders of consciousness. In light of these points, a new way of thinking about disorders of consciousness is presented in the chapter to more effectively guide clinical decision-making. The chapter argues that these considerations bring clarity to disorders of consciousness and can improve the ethical management of patients suffering from these disorders.

Despite the impressive progress that has been made in neuroscience, little has changed for patients with disorders of consciousness who struggle for access to even basic diagnostic and rehabilitative services as they remain sequestered from the scientific advances, which might make a difference in their lives. Although this is certainly a question of access to care, it is more than an entitlement issue. It is fundamentally a question of human rights in which a class of patients have been denied voice and been victimized by segregation and disinterest. This chapter considers how current practices and ethical norms should evolve to reflect progress in the neurosciences for this neglected population. In making these recommendations, it draws parallels to the US Civil Rights Movement, a struggle worthy of emulation as we consider ways to achieve integration and parity in civic life for a population society has forgotten.

This chapter reviews the diagnostic classification of disorders of consciousness, severe brain injuries that span a spectrum of brain states ranging from coma to the vegetative and minimally conscious states. The chapter makes the key point that brain states can – and do – evolve over time and that it is critical to be vigilant of changes that indicate that a patient who was unconscious is now conscious, albeit minimally so. The chapter describes how this traditional nosology is being challenged, and refined, by emergent technologies like neuroimaging and the ethical implications of this evolution for clinical practice and research. Specifically, the chapter addresses the challenge posed by discordant assessments when the clinical examination is brought into question by neuroimaging data that suggests that the patient is operating at a higher functional status than indicated by purely behavioral measures of assessment. Finally, drawing upon in-depth interviews of families touched by disorders of consciousness, the chapter explores family experiences and expectations, and suggests that these data indicates that the overriding goal of care, as understood by families, is the restitution of functional communication for this population silenced, at least in part, by disorders of consciousness.

In conformity with previous practice, consciousness is broken into two forms, here called the state of consciousness and the acts of consciousness. In contrast to previous practice, they are defined not by mental processes but by observable behaviors. The state of consciousness is defined by the person’s ability to respond to simple stimuli such as those used by the anesthesiologist in judging the return from anesthesia. A high level of global brain energy, and its accompanying neuronal activity, is shown by PET and MRS experiments to be necessary for maintaining the person in the observable state of consciousness.

This chapter examines neuromodulation for some neurological and psychiatric disorders. Deep brain stimulation (DBS) has been used experimentally in attempts to increase the levels of awareness and other cognitive and motor functions in patients with prolonged disorders of consciousness. Studies showing limited functional recovery after use of this technique raise questions about whether or to what extent these patients can benefit from it. DBS and responsive neurostimulation (RNS) may prevent or reduce the incidence of epileptic seizures by modulating electrical activity in the cortex. Although activation of electrodes modulates the electrical activity in their brains, people with these implants can turn them on and off and regulate the frequency and duration of the stimulation. There is both unconscious control by the implant and conscious control by the person with the implant. This conscious control can make persons responsible for how they use the devices and the consequences of this use. DBS can also enable people with addiction and aggressivity to inhibit hyperactivity in brain regions associated with these disorders and regain control of their behaviour. This includes not only physical actions but also the cognitive ability to foresee the probable consequences of activating and deactivating the device. The chapter also examines questions about fairness in access to neurostimulation devices in studies and clinical trials.

This chapter discusses metaphysical and ethical issues regarding the neurological and psychological effects of injuries to the brain. It examines the issue of personal identity by examining how these injuries can cause amnesia, disrupting the psychological continuity necessary for one to survive as the same person, and how they can harm individuals by defeating their interest in surviving. It also discusses disorders of consciousness resulting from these injuries, whether an individual with such a disorder continues to exist as a person, and how he can be harmed by it. It considers whether consciousness has value or disvalue. It also explores the respects in which interventions designed to restore physical and cognitive functions for these individuals can benefit or harm them.

When scholars write about personalized medicine, most refer to the interpretation of molecular biomarkers for the development of therapeutics tailored to an individual’s disease. By moving beyond pathological phenotypes to better characterize disease and guide treatment, next-generation personalized medicine moves more deeply into the biology of the malady to refine diagnostics at a genotypic, or molecular level. By understanding the unique biology of an individual’s disease, in most cases a malignancy, personalized therapies can be directed against specific biological targets. This focus maximizes therapeutic effect, decreases the variance of therapeutic response through more accurate diagnostic classification, and minimizes side-effects. This chapter suggests another domain where the metaphor of personalized medicine is apt and considers its application to the emerging diagnostics, therapeutics, and neuroethics informing the care of patients with disorders of consciousness. These conditions comprise a range of brain states that span coma, the vegetative, and minimally conscious states. Each of these states has behavioural and biological characteristics that warrant review and consideration for our discussion of personalized medicine. As in other domains of personalized medicine, patients presenting similarly at the bedside may have meaningful differences in their underlying neural circuitry. These distinctions, or the discordance between observed phenomenology and unobserved neurobiology, may have normative implications for the diagnosis and treatment of these conditions.