Abstract
Many research fields concerned with the processing of information contained in human faces would benefit from face stimulus sets in which specific facial characteristics are systematically varied while other important picture characteristics are kept constant. Specifically, a face database in which displayed expressions, gaze direction, and head orientation are parametrically varied in a complete factorial design would be highly useful in many research domains. Furthermore, these stimuli should be standardised in several important, technical aspects. The present article presents the freely available Radboud Faces Database offering such a stimulus set, containing both Caucasian adult and children images. This face database is described both procedurally and in terms of content, and a validation study concerning its most important characteristics is presented. In the validation study, all frontal images were rated with respect to the shown facial expression, intensity of expression, clarity of expression, genuineness of expression, attractiveness, and valence. The results show very high recognition of the intended facial expressions.
Acknowledgements
The Radboud Faces Database was financed by the Behavioural Science Institute of the Radboud University Nijmegen. Skyler T. Hawk is currently a postdoctoral researcher at the Research Centre Adolescent Development, Utrecht University.
We thank Job van der Schalk for his help as a FACS specialist.
Notes
1Here we report the intraclass correlations ICC(1, 1) and ICC(1, k) as reliability indices (Shrout & Fleiss, Citation1979). Due to the fact that our participants did not rate the whole image set but only parts, we could not calculate the usually higher indices ICC(2, 1) and ICC(2, k) that partial between-rater variance out. Therefore, our reliability indices are probably lower than the real reliability.