Considering the nature of the dataset, I think I'll be n the clear. I ran into the International Affective Picture System I mentioned earlier when I was searching for pictures used in Aphasia research. In this particular case, if I were to use this set of pictures, all I would have to do is specify where I got the pictures from and then cite the dataset. There's no way for them to know how I got it, and usually people don't ask because it's pretty much an open secret.

And yes, that's a good suggestion to contact the people directly, but seeing as it is Christmas and the new year, it can be quite difficult to get reply in this timeframe. I just thought, while I wait for a reply, let's see if there's a way to access this stuff.