A random dot kinematogram for online visual psychophysics

Online experiments using visual stimuli have become increasingly common in recent years, but many frequently-used stimuli in visual psychophysical experiments have yet to be developed for web-based platforms. Here, we introduce the first open-access random-dot kinematogram (RDK) for use in web browsers. This fully-customizable RDK offers options to implement several different types of noise (random position, random walk, random direction) and parameters to control aperture shape, coherence level, the number of dots, and many other features. We include links to commented JavaScript code for easy implementation in online experiments, as well as an example of how this stimulus can be integrated as a plugin with an online experimental library (jsPsych).