Okay great. Come back and enlighten us. :^)
After reading the study and a couple of additional articles, this is what I is what I understand.
If a person's brain is injured his or her level of consciousness may be impaired. The levels of impaired awareness are:
A person in a 'vegetative state' can no longer reason, think, recognize the presence of loved ones, or feel emotions or discomfort. If this state lasts more than four weeks, it is called a 'persistent vegetative state.'
Minimally conscious patients may show a very small awareness of themselves and their surroundings and may feel pain.
Now, to the study, and it's a doozy.
The researchers studied 38 people - 8 healthy adults and 30 patients who were either in a persistent vegetative state or minimally conscious.
Test results for nine of the thirty impaired patients were tossed out due to "excessive noise artefact." Results were analyzed from the healthy adults, from 9 patients in a persistent vegetative state, and from 12 minimally conscious patients. That's a total of 29 total test subjects.
Subjects were wired to special EEG machines and fitted with headphones. The researchers then played 90-second blocks of random monosyllabic words such as "moss, stone, house" with "yes" and "no" randomly included. The random-word test was repeated twenty times for each subject. For each test, the subject would be told either to count the times "yes" was said, or the times the word "no" was said. If "yes" was the target word, the researchers looked at the subject's EEG reaction to the word "no." If "no" was the target, EEG reaction to the word "yes" was examined.
EEG results of the impaired patients were compared to the EEG results of the eight 'healthy' patients.
In the experiment, ONE subject in a persistent vegetative state experienced a similar EEG reaction to the yes/no test as did the healthy subjects. She was young, had only been in a PVS for fifth months, and had minimal brain damage.
Three minimally conscious subjects reacted to novel words said during the test, but not to the yes/no directions.
Subjects were then asked to imagine a tennis game being played. One singular PVS/MC subject demostrated EEG results similar to the healthy subjects. It was the same young lady who had reacted to the yes/no test.
I greatly simplified this explanation, because I didn't fully understand elements such as the statistically compared single-subject reference-free magnitudes of electrical potential over the head of the grand averaged event-related potentials elicited by explicit targets in healthy volunteers, all as a function of time, within the 100–400 ms frontal P3a window and the 400–700 ms parietal P3b window to the − 300–0 ms baseline window using a non-parametric randomisation test. I admit my attempt to understand what that means was rather brief.
If you know, then I'd appreciate you explaining it to me as if I were a five year old.