My ADHD is measurable on EEG (I had the appropriate medical professional do it at a hospital, not some home-made braincap). Has nothing to do with anything external IME.
I'm sorry but I don't know. I was laying down, eyes closed with light patterns blasting into them, and instructed to try to not focus on anything. Afterwards, I got a written report from the concilium (3 people were studying the recording for a few days), but that did not include these details, it's intended for layperson like me and it simply says "Conclusion: ADHD very likely, hints of Asperger syndrome too.". I inquired about getting the brain-recording file, but they said I'd have to get it in person (I had it done in my home town where I don't live).
That's probably why the report said only "very likely" and not "has it". Afterwards I went to a psychologist who gave me a report with "Conclusion: ADHD confirmed, ... [lengthy description of my impairment]" and referred me to a psychiatrist.
It wasn't a standard procedure. My mother works at a neurochirurgy-focused hospital clinic and the doctor who measured it basically told her "hold my beer, I can see it", and so I went to see it. It was nice because this doctor also referred me to MRI just to be safe.
Cool. I have a consumer-grade Muse EEG thing. I learned about theta and ADHD links and thought it was probably bullshit. I figured out how to get the raw data with nodejs after years of using their app.
The patterns were jaw-dropping. My graphs were all theta. It's like I'm driving my brain around with the handbrake on. It was pretty startling. I dropped that EEG project after a few hours lol I should get back to it to see if I can change my brainwaves...
Anyways, here's some links to give a cardinal direction on this:
None based on the EEG itself, I was referred to a psychologist who did a questionnaire with me + attention tests - I was building patterns out of small bricks based on images, repeating numerical series forwards and backwards, listening to a story and talking about it, etc. I got a much more final conclusion (the report says "ADHD confirmed") there and now I'm supposed to go to a psychiatrist with that.
ADHD is absolutely measurable on an EEG (I've seen it done), but asperger is A. not a real current diagnosis and B. is not clearly measurable on an EEG AFAIK. Because of how old of a diagnosis Asperger is, I would have real doubts with one.
I was then referred to a psychologist who nearly immediately dismissed that one (and confirmed the ADHD with attention tests etc), so you're probably right.