Emotion recognition training using composite faces generalises across identities but not all emotions

Many cognitive bias modification (CBM) tasks use facial expressions of emotion as stimuli. Some tasks use unique facial stimuli, while others use composite stimuli, given evidence that emotion is encoded prototypically. However, CBM using composite stimuli may be identity- or emotion-specific, and may not generalise to other stimuli. We investigated the generalisability of effects using composite faces in two experiments. Healthy adults in each study were randomised to one of four training conditions: two stimulus-congruent conditions, where same faces were used during all phases of the task, and two stimulus-incongruent conditions, where faces of the opposite sex (Experiment 1) or faces depicting another emotion (Experiment 2) were used after the modification phase. Our results suggested that training effects generalised across identities. However, our results indicated only partial generalisation across emotions. These findings suggest effects obtained using composite stimuli may extend beyond the stimuli used in the task but remain emotion-specific.