Online research in philosophy

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.

We suggest that consciousness (C) should be addressed as a multilevel concept. We can provisionally identify at least three, rather than two, levels: Gray's system should relate at least to the lowest of these three levels. Although it is unlikely to be possible to develop a behavioural test for C, it is possible to speculate as to the evolutionary advantages offered by C and how C evolved through succeeding levels. Disturbances in the relationships between the levels of C could underlie mental illness, especially schizophrenia.

A pressing issue in neuroscience is the high rate of misdiagnosis of disorders of consciousness. As new research on patients with disorders of consciousness has revealed surprising and previously unknown cognitive capacities, the need to develop better and more reliable methods of diagnosing these disorders becomes more urgent. So too the need to expand our ethical and social frameworks for thinking about these patients, to accommodate new concerns that will accompany new revelations. A recent study on trace conditioning and learning in vegetative and minimally conscious patients shows promise as a potential diagnostic and prognostic tool, both for differentiating between states of diminished consciousness, and for predicting patient outcomes, but it also generates fresh concerns about quality of life in patients previously thought to be completely unaware. Optimism about progress in diagnosing and treating disorders of consciousness must be tempered by the understanding that not all progress will necessarily be good for all patients. The prognosis for most patients remains bleak, and we must remain vigilant to acute questions and concerns about welfare and quality of life.

The main goal of Brain Death and Disorders of Consciousness is to provide a suitable scientific platform to discuss all topics related to human death and coma.

The application of neuroimaging technology to the study of the injured brain has transformed how neuroscientists understand disorders of consciousness, such as the vegetative and minimally conscious states, and deepened our understanding of mechanisms of recovery. This scientific progress, and its potential clinical translation, provides an opportunity for ethical reflection. It was against this scientific backdrop that we convened a conference of leading investigators in neuroimaging, disorders of consciousness and neuroethics. Our goal was to develop an ethical frame to move these investigative techniques into mature clinical tools. This paper presents the recommendations and analysis of a Working Meeting on Ethics, Neuroimaging and Limited States of Consciousness held at Stanford University during June 2007. It represents an interdisciplinary approach to the challenges posed by the emerging use of neuroimaging technologies to describe and characterize disorders of consciousness.