What Would a Thought Look Like?

For the last couple of years The Hastings Center has been running a research project with the title, “On the Uses and Misuses of Neuroimaging Technology.” The central purpose of the project is to understand what really can be learned from neuroimaging. What does an image of changes in blood flow in a person’s head actually tell us?

This question is also the driving concern in two essays in this issue of the Hastings Center Report. Recent and much-publicized research into disorders of consciousness, such as the persistent vegetative state, seems to suggest that cases of conscious persons buried inside inert bodies may be somewhat more common than we thought, and that we might be able to devise strategies for communicating with these people even though their bodies remain inert. The research depends on functional magnetic resonance imaging scans that purportedly allow one to recognize when a person has certain patterns of thought.

The problem is that, if one is impressed by the technology’s power and potential benefit at all, then it seems all too easy to be overimpressed by it. People looking at a scan of blood flow changes tend to believe they’re seeing a thought. As the authors in the first essay observe, “some interpretations of the fascinating new fMRI studies seem to conflate findings associated with willful consciousness with the actual occurrence of willful consciousness.”

Both essays try to sort out the limits of what the scans can tell us and how they can be used. J. Andrew Billings and colleagues draw out the implications of the fact that the scans do not show us actual mental phenomena, such as consciousness and reasoning. Joseph Fins and Nicholas Schiff caution that at most, the scans present the possibility of posing a series of yes/no questions, and they caution that such a simple exchange will not allow a patient suffering a serious disorder of consciousness to evince a depth and nuance of understanding that is commensurate with the gravity of the medical decisions the patient faces.

Of course, the problem with calling attention to a technology’s limitations is that one can come off looking like nothing but a critic. The neuroimaging technology at stake here is genuinely important. The authors agree that the scans establish that we do not yet adequately understand disorders of consciousness and that we occasionally misdiagnose patients. The scans also raise the possibility that we do not understand what a person with a disorder of consciousness is experiencing. Not all human experience depends on higher levels of cortical functioning. Even if only a few patients turn out to be reasoning, many more patients may be suffering than we have recognized.

— GEK [End Page 2]