Prototypicality and intensity of emotional faces using an anchor-point method.

Emotional faces are commonly used as stimuli in a wide number of research fields. The present study provides values of 198 pictures from one of the amplest available face databases, the Karolinska Directed Emotional Faces (KDEF). We used a new validation strategy that consisted of presenting pairs of faces which included an emotional face (i.e., angry, happy, sad) and its corresponding neutral face from the same model. This design allowed participants to keep a comparison face (i.e., neutral) as a constant anchor point to evaluate parameters on each emotional expression presented. Raters were asked to judge both the prototypicality of the emotional expressions (i.e., the degree to which they represent their corresponding emotional prototypes) as well as their emotional intensity. We finally discuss the potential advantages of this anchor-point method as a system to elicit judgments on facial emotional expressions.