Previous research has indicated that individuals expressing high schizotypal traits and patients with Schizotypal Personality Disorder (SPD), show deficits in facial emotion recognition, compared to low schizotypal or control groups. On the other hand, non-significant findings also exist and the association of facial emotion recognition deficits with the different schizotypal dimensions is not well defined, thus limiting any conclusive outcomes. Therefore, the aim of this systematic review was to further clarify this relationship.
PsychInfo, Web of Science, Scopus and PubMed were systematically searched, and 23 papers with a cross-sectional design were selected. Nineteen studies examined individuals with high schizotypal traits and four studies evaluated SPD individuals with behavioural facial emotion recognition paradigms and self-report measures or clinical interviews for schizotypal traits. All selected studies were published between 1994 and August 2020.
According to the evidence of studies, high schizotypal individuals and SPD patients have poorer performance in facial emotion recognition tasks. Negative schizotypy was related to lower accuracy for positive and negative emotions and faster emotion labeling while positive schizotypy was associated with worse accuracy for positive, negative and neutral emotions and more biases. Disorganized schizotypy was associated with poorer accuracy for negative emotions and suspiciousness with higher accuracy for disgust faces but lower total accuracy.
These findings are consistent with the vulnerability for schizophrenia spectrum disorders and support the idea that emotion recognition deficits are trait markers for these conditions. Thus, the effectiveness of early-intervention programmes could increase by also targeting this class of deficits.