Two proposals have been put forward to account conjointly for the spatial-numerical association of response codes (SNARC) effect and the spatial-positional association of response codes (SPoARC) effect: the working memory account and the dual account. Here, on the basis of experimental and theoretical knowledge acquired in the field of expert memory, we propose an alternative account-named the expertise account-that explains both effects through the acquisition and use of knowledge structures (a generalization of "chunks," "retrieval structures," and "templates"), which have been used extensively in expert memory theory. These knowledge structures can be of two types: nonslotted or slotted schemas. We suggest that the SNARC effect can be explained via the use of nonslotted schemas, and the SPoARC effect via slotted schemas. We conclude our article by presenting the broader implications of our framework for working memory in general, when considering knowledge structures.
Keywords: Expertise; Mathematical cognition; Ordinal position effect; Retrieval structures; SNARC; SPoARC; Spatial cognition; Templates; Verbal working memory; Working memory.