In this journal article certain symptoms are called "activation" in nature. I have never come across this term prior to coming across this article, so I would like to know quite simply what does it mean.
The authors use the Positive and Negative Syndrome Scale (PANSS) to assess symptoms. One of its cluster scores is activation factor.
Original publication of the article, which doesn't list activation factors: http://schizophreniabulletin.oxfordjournals.org/content/13/2/261.long
Marketed currently here: http://www.mhs.com/product.aspx?gr=cli&id=overview&prod=panss
None of the sources I saw specified what is meant by activation factor, and many didn't even mention it. It's possible that it's the hyperactivity mentioned in the original publication. Also, it's possible that it's a modified category in the version sold at the last link. Hopefully this is enough information to get you started, if you want to hunt down the details.