Working memory and referential communication: An investigation of the cognitive factors affecting the production of overspecified referring expressions

Abstract

Language production often requires speakers to convey information to a conversational partner about objects in their environment. According to Grice’s Maxim of Quantity (1975), speakers should provide only the precise amount of information needed to identify an object. However, it is frequently observed that speakers will include redundant adjectives in their referring expressions, rendering their descriptions overspecified. The majority of the research investigating overspecification has focused on how scene characteristics influence the likelihood of this behaviour. To date, less is known about the internal characteristics of the speaker that may play a role in the production of overspecified descriptions, and in referential communication more generally. The current experiment investigates the role of working memory in the generation of referential descriptions and examines how this interacts with manipulations of scene characteristics and cognitive load. Participants were asked to provide instructions to a confederate about which object to select from an array of either three or six unrelated objects while they simultaneously remembered a series of either zero, three, or five numbers. Participants also completed an operation span task to measure their individual working memory capacity (WMC). Results showed a main effect of array size for speech onset times, confirming that speakers are faster to initiate their speech when there are fewer objects in the display. Further, there was a significant three-way interaction between array size, cognitive load, and operation span scores, indicating that speakers with lower WMC are more likely to use redundant adjectives for three object arrays under low levels of load. Finally, there was a significant, negative correlation between speech rate and adjective use, indicating that speakers adjust their rate of speech depending on their choice of referring expression. The results of this research suggest a potential role for individual WMC in the production of overspecified descriptions.