It Takes Time to Prime: Semantic Priming in the Ocular Lexical Decision Task

Abstract

Two eye-tracking experiments were conducted in which the manual response mode typically used in lexical decision tasks (LDT) was replaced with an eye-movement response through a sequence of three words. This ocular LDT combines the explicit control of task goals found in LDTs with the highly practiced ocular response used in reading text. In Experiment 1, forward saccades indicated an affirmative LD on each word in the triplet. In Experiment 2, LD responses were delayed until all three letter strings had been read. The goal of the study was to evaluate the contribution of task goals and response mode to semantic priming. Semantic priming is very robust in tasks that involve recognition of words in isolation, such as LDT, while limited during text reading as measured using eye movements. Gaze durations in both experiments showed robust semantic priming even though ocular response times were much shorter than manual LDs for the same words in the English Lexicon Project. Ex-Gaussian distribution fits revealed that the priming effect was concentrated in estimates of τ, meaning that priming was most pronounced in the slow tail of the distribution. This pattern shows differential use of the prime information, which may be more heavily recruited in cases where the LD is difficult as indicated by longer response times. Compared to the manual LD responses, ocular LDs provide a more sensitive measure of this task-related influence on word recognition as measured by the LDT.Keywords semantic priming; goal-driven processing; response time distributions; lexical decision; eye tracking during word reading Isolated word recognition tasks are an extremely popular tool for studying language at all levels of processing. In particular, the lexical decision task (LDT) (Meyer & Schvaneveldt, 1971;Rubenstein, Garfield & Millikan, 1970), has become a staple of psycholinguistic research. In addition to its steady growth in popularity as evidence in psychological research, applications now include several mega-studies, such as the English Lexicon Project (ELP) (Balota, et al., 2007) and the Groot Nationaal Onderzoek Taal organized across Flanders and The Netherlands (Brysbaert, Keuleers, Mandera & Stevens, 2013). Studies of the recognition of words presented in isolation and during text reading have yielded highly consistent evidence about many facets of word recognition (Schilling, Rayner Address correspondence to: Peter C. Gordon, Department of Psychology, CB#3270, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3270, pcg@unc.edu. & Chumbley, 1998), suggesting there is a substantial amount of overlap between the processes required for successful performance on isolated word recognition tasks and the reading of text for comprehension. However, differences in the specific demands made by each task require more detailed understanding before evidence from isolated word recognition studies can be used directly to improve our understanding of word recognition during text reading. NIH Public AccessLike other tasks...