`  == citation needed ==  ``usually retain their intellectual abilities`` Not even in the handbook for higher education that I used as a reference for some of what I added to this article, not even in that, could I find anything referring to the impairment of intellectual abilities. From what evidence I can find, there is nothing indicating such an impairment is at all an aspect of ABI, and therfore I am hereby removing the word ``usually`` from the sentence.   `