A COGNITIVE THEORY OF GRAPHICAL AND LINGUISTIC REASONING - LOGIC AND IMPLEMENTATION

We discuss external and internal graphical and linguistic representati onal systems. We argue that a cognitive theory of peoples' reasoning p erformance must account for (a) the logical equivalence of inferences expressed in graphical and linguistic form, and (b) the implementation al differences that affect facility of inference. Our theory proposes that graphical representation limit abstraction and thereby aid ''proc essibility.'' We discuss the ideas of specificity and abstraction, and their cognitive relevance. Empirical support both comes from tasks wh ich involve the manipulation of external graphics and tasks that do no t. For the former, we take Euler's (1772) circles, provide a novel com putational reconstruction, show how it captures abstractions, and cont rast if with earlier construals and with Johnson-Lairds (1983) mental models representations. We demonstrate equivalence of the graphical Eu ler system, and the nongraphical mental models system, For tasks not i nvolving manipulation of external graphics, we discuss text comprehens ion, and the mental performance of syllogisms. By positing an internal system with the some specificity as Euler's circles, we cover the men tal models data, and generate new empirical predictions. Finally. we c onsider how the architecture of working memory explains why such speci fic representations are relatively easy to store.