Has the effects of fighting all them years, effected Roy Jones jr?

I was watching some of the pre fight/post fight interviews Roy did for the Montel Griffin fight on youtube and I noticed how clear, lively and charismatic a younger Roy Jones jr was in his speeches. Then I watched a couple of his build up promotional speeches for the Roy Jones vs Calzaghe fight and the first thing that struck me is how Roy Jones just seems a shell of his former self, if you listen to him speaking he slurs his words and generally is slower in his speech, like it is a slight effort for him, the thinking process has slowed down. I was just wondering if the effects of all them 56 fights over the course of 18 or so years has had an effect on him mentally. Don't get me wrong i am not trying to knock Roy Jones in anyway i think the bloke is a legend but it was just something i picked up on, he definitely doesn't sound the same as the young Roy once did, anyone else noticed this?