The Morris water maze has been put forward in the philosophy of neuroscience as an example of an experimental arrangement that may be used to delineate the cognitive faculty of spatial memory (e.g., Craver and Darden, Theory and method in the neurosciences, University of Pittsburgh Press, Pittsburgh, 2001; Craver, Explaining the brain: Mechanisms and the mosaic unity of neuroscience, Oxford University Press, Oxford, 2007). However, in the experimental and review literature on the water maze throughout the history of its use, (...) we encounter numerous responses to the question of “what” phenomenon it circumscribes ranging from cognitive functions (e.g., “spatial learning”, “spatial navigation”), to representational changes (e.g., “cognitive map formation”) to terms that appear to refer exclusively to observable changes in behavior (e.g., “water maze performance”). To date philosophical analyses of the water maze have not been directed at sorting out what phenomenon the device delineates nor the sources of the different answers to the question of what. I undertake both of these tasks in this paper. I begin with an analysis of Morris’s first published research study using the water maze and demonstrate that he emerged from it with an experimental learning paradigm that at best circumscribed a discrete set of observable changes in behavior. However, it delineated neither a discrete set of representational changes nor a discrete cognitive function. I cite this in combination with a reductionist-oriented research agenda in cellular and molecular neurobiology dating back to the 1980s as two sources of the lack of consistency across the history of the experimental and review literature as to what is under study in the water maze. (shrink)

Recent studies indicate that patients who are diagnosed with vegetative states may retain more awareness than their clinical assessments suggest. Disorders of consciousness traditionally have been diagnosed on the basis of outwardly observable behaviors alone, but new functional imaging studies have shown surprising levels of brain activity in some patients, indicating that even higher-level cognitive functions like language processing and visual imagery may be preserved. For example, one recently developed method purports to detect voluntary mental imagery solely on the basis (...) of neural response patterns observed with functional magnetic resonance imaging. This line of research has already led to some widely reported cases of patients who were discovered to have more brain activity than expected. In November 2009, Rom Houben, a Belgian man who was thought to be in a coma for 23 years, was diagnosed with locked-in syndrome through the use of neuroimaging; however, that assessment was later overturned by further testing. (shrink)

In this paper, we review recent neuroimaging investigations of disorders of consciousness and different disciplines' understanding of consciousness itself. We consider potential tests of consciousness, their legal significance, and how they map onto broader themes in U.S. statutory law pertaining to advance directives and surrogate decision-making. In the process, we outline a taxonomy of themes to illustrate and clarify the variance in state-law definitions of consciousness. Finally, we discuss broader scientific, ethical, and legal issues associated with the advent of neuroimaging (...) for disorders of consciousness and conclude with policy recommendations that could help to mitigate confusion in this realm. (shrink)

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. (shrink)