Whether or not there is any conscious awareness with a patient's vegetative state is a prominent issue. Three completely different aspects of this should be distinguished. First, some patients can be conscious simply because they are misdiagnosed (see above). In fact, they are not in vegetative states. Second, sometimes a patient was correctly diagnosed but is then examined during the early stages of recovery. Third, perhaps some day the notion itself of vegetative states will change so to include elements of conscious awareness. Inability to disentangle these three example cases causes confusion. An example of such confusion is the response to an experiment using functional magnetic resonance imaging which revealed that a woman diagnosed with PVS was able to activate predictable portions of her brain in response to the tester's requests that she imagine herself playing tennis or moving from room to room in her house. The brain activity in response to these instructions was indistinguishable from those of healthy patients.