Observable behavior, such as test scores, is the gold standard by which we make judgments about levels of function, grade placements, and the presence/absence of pathology. Individual differences in test performance have long intrigued researchers and clinicians, and some have noted how people can come up with essentially the same answers using different strategies. Thus, product, or overt test score, does not always tell us about the underlying cognitive or neurological process involved. We provide results from an ongoing brain imaging study of spatially superior--reading disabled adults, showing how different, hitherto unseen, neural processes can yield similar overt test behavior in some domains and not others. These data raise our awareness of how individual differences in neurology might be considered alongside behavioral observations. Implications for practice and how these data address assumptions in the twice-exceptional field are discussed.