In science, a "control group" is a group of test subjects that do not receive any of the experimental food/ gas/ poison/ bizarre additions to their environment, etc., that the other groups in the...
"things that the person doing the experiment changes"
Both, because you need to control your mind in order for it to control you
Your Cerebellum. (: It's your memory cortex.
the group that does not change in the experiment VIVI :)