PsyBuilder: an Open-Source, Cross-Platform Graphical Experiment Builder for Psychtoolbox with Built-In Performance Optimization

Psychtoolbox is among the most popular open-source software packages for stimulus presentation and response collection. It provides flexibility and power in the choice of stimuli and responses, in addition to precision in control and timing. However, Psychtoolbox requires coding in MATLAB (or its equivalent, e.g., Octave). Scripting is challenging to learn and can lead to timing inaccuracies unwittingly. It can also be time-consuming and error prone even for experienced users. We have developed the first general-purpose graphical experiment builder for Psychtoolbox, called PsyBuilder, for both new and experienced users. The builder allows users to graphically implement sophisticated experimental tasks through intuitive drag and drop without the need to script. The output codes have built-in optimized timing precision and come with detailed comments to facilitate customization. Because users can see exactly how the code changes in response to modifications in the graphical interface, PsyBuilder can also bolster the understanding of programming in ways that were not previously possible. In this tutorial, we first describe its interface, then walk the reader through the graphical building process using a concrete experiment, and finally address important issues from the perspective of potential adopters.