In this repository you can find a version of the Brief Reverse Correlation Task that you can run locally on your computer (or host online if you know your way around servers and databases, e.g., netlify).
The Brief Reverse Correlation (Brief-RC) task, introduced by Schmitz et al. (2024), is an innovative method for capturing visual facial representations of social categories. It addresses the limitations of traditional psychophysical reverse correlation methods, which require numerous trials (300 to 1000s) to generate classification images (CIs) of acceptable quality. By increasing the number of stimuli ("noisy faces") presented in each trial, the Brief-RC task improves the quality of individual and average CIs while reducing the overall task length. This efficiency makes it a highly valuable tool for social psychology research, by enabling researchers to use the RC paradigm with less resources (all thanks to the team of Schmitz and collaborators, 2024).
Running the Experiment Locally:
- Download the HTML file (e.g.,
demo_briefrc_12_ENG.html) and theimagesfolder containing the task stimuli. - Place both the HTML file and the
imagesfolder in the same directory on your computer. - Run the experiment by opening the HTML file in your web browser.
The results will be automatically saved to your browser's default downloads directory (usually a folder called Downloads) upon completion.
Experiment Versions:
- Standard Version:
demo_briefrc_12_ENG.html - Version with Stimulus Verification:
demo_filename_check_briefrc_12_ENG.html
This version displays the filenames of the images during the experiment. Use this version to verify how the stimuli are presented and ensure proper counterbalancing.
For now, only the version of Brief-RC that presents 12 stimuli per trial is available.
I might add more versions in the future (e.g. 6 stimuli, or the traditional 2 stimuli per trial), but I think the 12 stimuli per trial strike a good balance between size of the images and how many of them might fit into a typical laptop screen (say 13" to 15").
The task uses noise patches superimposed on a composite image of average male and female faces with neutral expression from the Karolinska Face Database (Lundqvist & Litton, 1998). The stimulu were generated using the rcicr R package (Dotsch, 2016).
You can run a simple version of the Brief RC Task with 12 faces per trial on your local web browser here:
(https://olivethree.github.io/briefrc12online/)
This version includes 60 trials, participant number input, and some basic demographics. The target category is "Star Wars Fan", just for the sake of demonstration. The output data file includes all the necessary data (and more) to generate the classification images that reflect an approximation to the target mental representation of which facial cues predict the perception of the target trait category (Star Wars Fan) from a face.
Dotsch R. (2016). Rcicr: Reverse-correlation image-classification toolbox. R package (Version 0.3), 4. https://cran.r-project.org/web/packages/rcicr/index.html
Lundqvist, D., & Litton, J. E. (1998). The Averaged Karolinska Directed Emotional Faces - AKDEF, CD ROM from Department of Clinical Neuroscience, Psychology section, Karolinska Institutet, ISBN 91-630-7164-9.
Schmitz, M., Rougier, M., & Yzerbyt, V. (2024). Introducing the brief reverse correlation: An improved tool to assess visual representations. European Journal of Social Psychology. Advance Online Publication. https://doi.org/10.1002/ejsp.3100