HI Jerker, a couple of things. First we will have a comparison of two tasks, 1) sentence processing as a single task and 2) sentence processing under dual task situation (in the latter people have to track changes in a fixation cross, quite hard to do, but it works, we just piloted this.).
Apart from this we will run a few cognitive tests: Wortschatztest (a German vocabulary test that is assumed to measure verbal intelligence), digit span backwards, trail making test and reading span test.