Publications

Abstract

There is a growing interest in the use of webcams to conduct eye-tracking experiments over the internet. We assessed the performance of two webcam-based eye-tracking techniques for behavioral research: manual annotation of webcam videos (manual eye-tracking) and the
automated WebGazer eye-tracking algorithm. We compared these methods to a traditional
infrared eye-tracker and assessed their performance in both lab and web-based settings. In
both lab and web experiments, participants completed the same battery of five tasks, selected
to trigger effects of various sizes: two visual fixation tasks and three visual world tasks testing
real-time (psycholinguistic) processing effects. In the lab experiment, we simultaneously collected infrared eye-tracking, manual eye-tracking, and WebGazer data; in the web experiment, we simultaneously collected manual eye-tracking and WebGazer data. We found that the two webcam-based methods are suited to capture different types of eye-movement patterns. Manual eye-tracking, similar to infrared eye-tracking, detected both large and small effects. WebGazer, however, showed less accuracy in detecting short, subtle effects. There was no notable effect of setting for either method. We discuss the trade-offs researchers face when choosing eye-tracking methods and offer advice for conducting eye-tracking experiments over the internet.

Abstract

Bock et al. (1992) found that the binding of animacy features onto grammatical roles is susceptible to priming in sentence production. Moreover, this effect did not interact with structural priming. This finding supports an account according to which syntactic representations are insensitive to the consistency of animacy-to-structure mapping. This account has contributed greatly to the development of syntactic processing theories in language production. However, this study has never been directly replicated and the few related studies showed mixed results. A meta-analysis of these studies failed to replicate the findings of Bock et al. (1992). Therefore, we conducted a well-powered replication (n = 496) that followed the original study as closely as possible. We found an effect of structural priming and an animacy priming effect, replicating Bock et al.’s findings. In addition, we replicated Bock et al.’s (1992) observed null interaction between structural priming and animacy binding, which suggests that syntactic representations are indeed independent of semantic information about animacy.