Humanoid robots versus humans: How is emotional valence of facial expressions recognized by individuals with schizophrenia? An exploratory study

BACKGROUND The use of humanoid robots to play a therapeutic role in helping individuals with social disorders such as autism is a newly emerging field, but remains unexplored in schizophrenia. As the ability for robots to convey emotion appear of fundamental importance for human-robot interactions, we aimed to evaluate how schizophrenia patients recognize positive and negative facial emotions displayed by a humanoid robot. METHODS We included 21 schizophrenia outpatients and 17 healthy participants. In a reaction time task, they were shown photographs of human faces and of a humanoid robot (iCub) expressing either positive or negative emotions, as well as a non-social stimulus. Patients' symptomatology, mind perception, reaction time and number of correct answers were evaluated. RESULTS Results indicated that patients and controls recognized better and faster the emotional valence of facial expressions expressed by humans than by the robot. Participants were faster when responding to positive compared to negative human faces and inversely were faster for negative compared to positive robot faces. Importantly, participants performed worse when they perceived iCub as being capable of experiencing things (experience subscale of the mind perception questionnaire). In schizophrenia patients, negative correlations emerged between negative symptoms and both robot's and human's negative face accuracy. CONCLUSIONS Individuals do not respond similarly to human facial emotion and to non-anthropomorphic emotional signals. Humanoid robots have the potential to convey emotions to patients with schizophrenia, but their appearance seems of major importance for human-robot interactions.