Featural evaluation, integration, and judgment of facial affect

The paradigm of the fuzzy logical model of perception (FLMP) is extended to the domain of perception and recognition of facial affect. Two experiments were performed using a highly realistic computer-generated face varying on 2 features of facial affect. Each experiment used the same expanded factorial design, with 5 levels of brow deflection crossed with 5 levels of mouth deflection, as well as their corresponding half-face conditions, for a total stimulus set of 35 faces. Experiment 1 used a 2-alternative, forced-choice paradigm (either happy or angry), whereas Experiment 2 used 9 rating steps from happy to angry. Results indicate that participants evaluated and integrated information from both features to perceive affective expressions. Both choice probabilities and ratings showed that the influence of 1 feature was greater to the extent that the other feature was ambiguous. The FLMP fit the judgments from both experiments significantly better than an additive model. Our results question previous claims of categorical and holistic perception of affect.