So I tried an experiment. ...
Would the added "computer motivation" be enough for a child with an attention problem to pull himself together for a test? Is not having internal motivation part of ADHD? I had been thinking that his "not caring" attitude was a way of covering up feeling inadequate because he wasn't able to show his understanding on tests. But maybe I'm off base. . .
In the short run, especially, a higher value reinforcer can certainly change behavior in a kid with ADHD. There is even a study that shows that when the 'time to reward' is short, ADHD kids will perform as well on tasks as other kids, and they fall apart when the 'time to reward' is long.