Proceedings of the Annual Meeting of the Cognitive Science Society

Geminates (or double letters) are a feature of many languages, including English. Studies of the spelling errors produced by individuals with orthographic working memory deficits have provided evidence that geminates are not produced as two in- dependent instances of the same letter. Instead, there must be a special mechanism in the orthographic system that produces geminates. Several theories have attempted to model such mechanisms. However, in most cases, the predictions of such theories have been tested using data from single-case neuro- psychological studies. In the current study, we re-evaluate these theories using the largest corpus of geminate errors in typing collected to date, and show that no theory can explain all the findings. We then propose an enhanced model of gem- ination that can.