its nothing to worry about. Mental dsorders like DID cannot be detected on the EEG because it is a memory storage not chemical imbalance problem Certain ones like bipolor can be detected with blood tests because they are chemical imbalances - Lithium or dopamine for example. if a blood test shows a persons body doesn't have enough natural lithium the brain cant funtion normally. but they dont show up in EEG's. EEG's look for physical brain illnesses like epilepsy, tumors, apnea, and the sleep cycles like REM thats why they want you good and tired. when a person is tired the brain impulses "alpha" and "beta" show up better for the sleep cycle tests. They will ask you at times to keep your eyes closed or open depending on what they are looking for and which brain impulse Alpha or beta they are testing at that moment. They basically use these to rule out physical problems before ruling in a mental disorder.

When I did it they put a sort of cap on my head , kind of like a swimming cap people wear so they dont get their hair wet. only this cap has holed in it. through the holes the technition squirted this jelly goop that was in a tube like tooth paste. then on top of that he put patches and wires. then I just laid there. he told me at time to open or close my eyes so the computer could see how my brain reacted to seeing light and dark. afterwards it was real fun washing that goop out of my hair. I looked like I had taken a bath with vaseline for a few days. My friends son just had his done but they didnt use a cap on him, just goop and patches that had wires attached.