Mouse Tracking for Reading (MoTR): A New Naturalistic Incremental Processing Measurement Tool

Abstract

We present Mouse Tracking for Reading (MoTR) a new incremental processing measurement tool that can be used to collect word-by-word reading times. In a MoTR trial, participants are presented with text, which is blurred, except for a small region around the tip of the mouse. Participants must move the mouse in order to reveal and read the text. Mouse movement is recorded, and can be analyzed similar to gaze location in an eye tracking experiment. We validate MoTR in two suites of experiments: In the first experiment, we assess whether MoTR can be used to study sentence processing phenomena in targeted psycholinguistics experiments. Using materials from Witzel et al. (2012), we show that MoTR can reveal English speakers’ preferences for low attachment during online sentence comprehension. In the second experiment we record MoTR data for the Provo Corpus (Luke and Christianson, 2018). We show that MoTR data correlate well with previously-collected eye tracking data for this corpus, and that there is a roughly linear relationship between by-word MoTR values and word-level surprisal values, as has been previously shown for eye tracking data (Smith and Levy, 2013). We argue that MoTR presents a compelling tradeoff between multiple experimental considerations: It is cheap to run, and can be presented in a browser enabling collection of data over the internet. It is more naturalistic than some alternative processing measures, allowing participants to skip words and to regress to previous sentence regions. Finally, it has good sensitivity, producing word-by-word reading times that are comparable to eye tracking data.