Conditional Consciousness: Patients in Vegetative States Can

[Shirleypal]

September 20, 2009 | 9 comments

Conditional Consciousness: Patients in Vegetative States Can Learn, Predicting Recovery
Brain-damaged patients who appear to have lost signs of conscious awareness might still be able to create new memories, showing signs of new neural networks and potential for partial recovery
By Katherine Harmon

LATENT LEARNING?: If some vegetative patients can be shown to acquire conditional learning, should their status be reevaluated?
ISTOCKPHOTO/SEBCHANDLER
In patients who have survived severe brain damage, judging the level of actual awareness has proved a difficult process. And the prognosis can sometimes mean the difference between life and death.

New research suggests that some vegetative patients are capable of simple learning—a sign of consciousness in many who had failed other traditional cognitive tests. The findings are presented in a paper today in Nature Neuroscience (Scientific American is part of the Nature Publishing Group).

To decide whether patients are in a minimally conscious state (MCS), in which there is some evidence of perception, or intentional movement or have sunk into a vegetative state (VS), where there is neither, doctors have traditionally used a battery of tests and observations, many of which require some subjective interpretation, such as deciding whether a patient's movements are purposeful—to indicate a sullied feeding tube, for example—or just random.
http://www.scientificamerican.com/artic ... tive-state