Proceedings of the Annual Meeting of the Cognitive Science Society

It takes approximately one second for an adult to respond to the problem "7 x 8" The results of that second are well documented, and there are a number of competing theories attempting to explain the phenomena [Campbell & Graham 1985; Ashcroft 1987; Siegler 1988]. However. there are few fully articulated models available to test specific assumption [McCloskey, Harley, & Sokol 1991]. This paper presents a connectionist account of mental multiplication which models adult reaction time and error patterns. The phenomenon is viewed as spreading activation between stimulus digits and target products, and is implemented by a multilayered network augmented with a version of the "cascade" equations [McClelland 1979]. Simulations are performed to mimic Campbell & Graham s [1985] experiments measuring adults' memory for single-digit multiplication. A surprisingly small number assumptions are needed to replicate the results found in the psychological literature—fewer than some (less explicit) theories presuppose.