This is interesting. I have a deep brain stimulator installed in my brain and it has completely fixed the underlying problem. I have a couple of strange side effects, first when I turn the device up my eyes go crossed eyed the wrong way and then return to normal after a few seconds, the second is that I can absorb information much quicker. Now I always have had a photographic memory but thats declining over the years but the information I can gather is greatly enhanced.
It could be subjective but I went to do a research project with DARPA and they played around with the settings of my implant to test if they could affect things in people with an implanted device - so one day i was very pissed off and annoyed with them, the second I flew through the tests with flying colours.