Eye movements data for The effects of restrictiveness on relative clause processing in Farsi
Description We investigated whether there is any processing asymmetry between Farsi object and subject relative clauses and whether restrictiveness affects processing relative clauses by L1 Farsi speakers. To this end, with an eye-tracking method, we tested the effect of Clause Type and Restrictiveness in Farsi relative clauses. Forty-two Iranian Farsi speaking students at the University of Groningen participated in the experiment voluntarily. They were tested individually in the eye lab at the University of Groningen. Eye movements were recorded using a Tobii 1750 Eye tracker, interfaced with a laptop. The sampling rate was 50 HZ. The materials for this experiment consisted of 36 items, each consisting of four sentence versions. Initially, the items were adapted from Staub (2010) and Staub et al. (2017). For the present experiment, the items were translated into Farsi carefully and non-restrictive versions were added to the material. We divided the Farsi relative clause sentences into six regions: the antecedent, complementizer که /ke/, embedded noun phrase in the relative clause, embedded verb phrase in the relative clause, pre-matrix verb region, and matrix verb. For each region, four reading time measures of first-pass reading time (FP) or gaze duration, First-pass total reading time, Regression path duration (RPD), and Total reading time (TRT) were compared. Statistical analysis was conducted using linear mixed-effects models of the reading times. We used R (R Core Team, 2019) and the lme4 package (Bates et al., 2015) to predict the times of the eye movement measurements (first-pass, first-pass total, total reading time, regression path duration) based on Clause Type (subject versus object) and Restrictiveness (Restrictive versus Non-restrictive). As random effects, we included intercepts for subjects and items. We used treatment coding: The subject relative was the baseline for Clause Type and the restrictive condition was the baseline for Restrictiveness. First, we created a model with the main effects and then compared it with the model with the interaction. In the models, the subject relative was the baseline for Clause Type and the restrictive condition was the baseline for Restrictiveness. In the case of an interaction, an extra analysis was run to test the effect of Clause Type in the non-restrictive condition by changing the baseline for Restrictiveness into the non-restrictive condition.
Steps to reproduce
The data were produced by an eye-tracking method. While reading relative clause sentences, the eye movement measures of L1 speakers were recorded. The stimuli involve the subject and object relative clauses within restrictive and non-restrictive conditions.