We have included three data files and three R scripts for analysis. The three data files are the raw eyetracking data (fixations), the processed eyetracking data, and the subject-level individual difference measures (age of acquisition, proficiency, etc). The three R script files (1) take the raw data and make the processed data frame; (2) take the processed dataframe and perform growth curve analysis of the eyetracking data; (3) analyze accuracy and reaction times across trials.