Document Type




Journal Title

Proceedings of the 41st Annual Meeting of the Cognitive Science Society

Pub Date


Place of Publication

Montreal, Canada


Many studies on memory retrieval in language processing have identified similarity-based interference as a key determinant of comprehension. The broad consensus is that similarity-based interference reflects erroneous retrieval of a non-target item that matches some of the retrieval cues. However, the mechanisms responsible for such effects remain debated. Activation-based models of retrieval (e.g., Lewis & Vasishth, 2005) claim that any differences in processing difficulty due to interference in standard RT measures and judgments reflect differences in the speed of retrieval (i.e., the amount of time it takes to retrieve a memory item). But this claim is inconsistent with empirical data showing that retrieval time is constant due to the use of a direct-access procedure (e.g., McElree, 2000, 2006). According to direct-access accounts, differences in judgments or RTs due to interference arise from differences in the quality or availability of the candidate memory representations, rather than differences in retrieval speed. To adjudicate between these accounts, we employed a novel methodology that combined a high-powered (N = 200) twoalternative forced-choice study on interference effects with drift diffusion modeling to disassociate the effects of retrieval speed and representation quality. Results showed that the presence of a distractor that matched some of the retrieval cues lowered asymptotic accuracy, reflecting an effect of representation quality, but did not affect retrieval speed, consistent with a direct-access procedure. These results suggest that the differences observed in RTs and judgment studies reflect differences in the ease of integrating the retrieved item back into the current processing stream, rather than differences in retrieval speed.