$$\mu$$Cap: connecting FaceReader™ to z-Tree

Abstract

Cap is a software package (citeware) for economic experiments enabling experimenters to analyze emotional states of subjects using z-Tree and FaceReader™. Cap is able to create videos of subjects on client computers based on stimuli shown on screen and restrict recording material to relevant time frames. Another feature of Cap is the creation of time stamps in csv format at prespecified screens (or at prespecified points in time) during the experiment, measured on the client computer. The software makes it possible to import these markers into FaceReader™ easily. Cap is the first program that significantly simplifies the process of connecting z-Tree and FaceReader™ with the additional benefit of extremely high precision. This paper describes the usage, underlying principles as well as advantages and limitations of Cap. Furthermore, we give a brief outlook of how Cap can be beneficial in other contexts.

On Trust and Disgust: Evidence From Face Reading and Virtual Reality

“…We used the average value of each emotion over a 10-s interval before or after events of interest. 2 The synchronization with z-Tree was established using the MuCap program (Doyle & Schindler, 2015).…”

Teams and individuals in standard auction formats: decisions and emotions

“…Their magnitude was measured as a number between 0 and 1, captured multiple times per second. For each subject in each period, we took an average over those measurements within the first ten seconds that the subjects saw their feedback screen and used these measures for our analysis (synchronization between zTree and FaceReader was achieved by employing the software µCap by Doyle and Schindler, 2019). An additional composite variable "valence" amounts to the difference between measured happiness and the strongest negative emotion (anger, disgust, sadness, and fear).…”

Temporal Behavioral Parameters of On-Going Gaze Encounters in a Virtual Environment

“…A Python client for the FaceReader API (Noldus Information Technology, The Netherlands, tested for Versions 6.X and 7.X, available for Microsoft Windows only) is integrated and allows for emotion-contingent settings. For automated, synchronized video recordings of the participant during the experiment, support for video capturing via µCap (Doyle and Schindler, 2015) is implemented. This allows for synchronized offline analysis of video recordings of the experimental procedure, e.g., for in-depth offline facial action unit activity and emotion of the participant (Friesen and Ekman, 1978;Schulte-Rüther et al, 2017).…”