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. (shrink)