It says nothing about the severity of their illness, only about how typical they are of this cluster you see. So that's what we picked. Then we brought them in and showed in fact that they had more severe brain dysfunction than the controls. Now when neurologists tested these selected 23 individuals that you found, they couldn't find anything abnormal. And if you took the group of 23 as a whole, the results of these tests were not that different from normative data, but were different from a control group.
Normative data is a control group, but it's a control group of a cross-section of the population.