Look at that: Spatial deixis reveals experience-related differences in prediction

ABSTRACT

Prediction-based theories posit that interlocutors use prediction to process language efficiently and to coordinate dialogue. The present study evaluated whether listeners can use spatial deixis (i.e., this, that, these, and those) to predict the plurality and proximity of a speaker’s upcoming referent. In two eye-tracking experiments with varying referential complexity (N = 168), native English-speaking adults, native English-learning 5-year-olds, and nonnative English-learning adults viewed images while listening to sentences with or without informative deictic determiners, e.g., Look at the/this/that/these/those wonderful cookie(s). Results showed that all groups successfully exploited plurality information. However, they varied in using deixis to anticipate the proximity of the referent; specifically, L1 adults showed more robust prediction than L2 adults, and L1 children did not show evidence of prediction. By evaluating listeners with varied language experiences, this investigation helps refine proposed mechanisms of prediction and suggests that linguistic experience is key to the development of such mechanisms.

Acknowledgments

We thank all participants, as well as Cynthia Lukyanenko and Claire Robertson for assistance with stimuli, Naoum Fares Marayati and other research assistants at the Princeton Baby Lab for assistance with participant recruitment, Alexia Hernandez  and Kavindya Dalawella for assistance with data collection, and reviewers for helpful commentary on prior versions of this paper.

Notes

¹ To evaluate potential timing differences between the deictic conditions being compared, we analyzed the time duration between the onset of the determiner (e.g., this) and the onset of the target noun (e.g., cookie) for each comparison with two-tailed, paired-sample t-tests. Comparing singular deictic sentences (this/that) and plural deictic sentences (these/those), we found no significant difference in durations between determiner onset and target noun onset, t(15) = 0.58, p = 0.571. Comparing proximal deictic sentences (this/these) and distal deictic sentences (that/those), we again found no significant timing differences across conditions, t(15) = 0.42, p = 0.682. Thus, results indicate that participants had approximately equal time to generate predictions across conditions.

² Participants had a general bias to look toward proximal referents in both experiments. This pattern of looking behavior is most likely due to the fact that the speaker, by definition, was located near the proximal referents (e.g., Figure 4). Given the limited number of referents to look at within the visual display, participants sometimes looked to the speaker, and this may have automatically biased them to look more toward proximal referents.

³ This tentatively suggests that adults and children commonly use spatial deictic terms during everyday conversations. However, transcript data do not reveal whether deictic determiners were being used spatially (i.e., contrasting proximal and distal referents) as in the present study, nor do they indicate whether children and/or adults produced deictic determiners in contexts with shared, opposite, or orthogonal perspectives. Future investigations could use naturalistic video corpora to evaluate how caregivers and children use deictic determiners during everyday conversations. A project on natural use of spatial deixis in real-world referential contexts would be an excellent and ambitious complement to the present investigation.

Additional information

Funding

This research was supported by grants from the National Institute of Child Health and Human Development to Casey Lew-Williams [R01HD095912, R03HD079779] and from the National Science Foundation to Tracy Reuter [DGE-1656466].