What do reading times tell us about the effect of orthographic regularity? Evidence from English and Italian readers

Introduction We examine the impact of orthographic depth focusing on English and Italian—two languages with quite different orthographies. Materials and Methods We review a set of studies comparing English and Italian readers on time measures, in particular, reaction times (RTs). An advantage of using time measures is the availability of processing models that provide a useful interpretative framework (i.e., rate and amount model, RAM; difference engine model, DEM). The data indicate that English children are generally less accurate but not slower than Italian children; furthermore, they are more variable than Italian readers, a tendency confirmed with different paradigms (e.g., rapid serial visual presentation) and age groups (i. e., young adults). While data from Italian children fit very closely with the predictions of the RAM and DEM, those of English children showed several deviations from these models. Thus, we examined whether differences in strategy (or a response criterion) might explain such deviations. In a lexical decision study based on the diffusion model, English young adults showed a more lenient criterion, i. e., they needed less evidence to decide on the lexical quality of the stimulus. Drawing on the multiple read-out model (MROM), we propose that the irregularity of the English orthography may favor reference on the Σ criterion (based on general evidence), while the regular Italian orthography may favor reliance on the M criterion (based on evidence for a specific word). Results Overall, we put forward two working hypotheses to interpret the overall pattern of experimental findings. First, the characteristics of the English orthography (possibly emphasized by the teaching method used) foster a global, lexical, approach to recognizing words. Second, not all children can effectively rely on such global processing, and this may be the main source of large individual differences in the English sample. Conclusion Understanding the source of these individual differences still represents a challenging task for future research.