Automated Analysis of Smiling Mimicry Across the Psychosis-Risk Continuum

Early identification and support for individuals with psychotic-like experiences (PLEs) are essential for timely intervention and improved outcomes. Emotional mimicry, which refers to the automatic imitation of another person's emotional expression, such as a smile, is a fundamental social process that supports smooth interpersonal interaction and is known to be impaired in schizophrenia. However, its role across the broader psychosis-risk continuum remains unclear. This study examined smiling mimicry (the emotional mimicry of smiling) in individuals with PLEs and explored its relationship with key negative symptoms. Secondary analyses explored whether such patterns were particularly characteristic of a clinical high-risk (CHR) subgroup.

A total of 102 participants were categorised into a PLE group (n = 75) or a healthy control group (HCs; n = 27) using structured clinical interviews. Within the PLE group, a subset met CHR criteria (n = 41). Negative symptoms were assessed using the Negative Symptom Inventory-Psychosis Risk (NSI-PR). Zoom recordings from clinical assessments were analyzed using FaceReader, an automated facial expression analysis tool.

Primary analyses showed no overall group differences between PLE and HC participants in smiling mimicry. However, within the PLE group, mimicry was significantly negatively associated with blunted affect (r = -0.36, p = 0.002). In secondary analyses, CHR participants did not differ from HCs in smiling mimicry.

These findings highlight the value of automated facial analysis for detecting subtle interpersonal deficits and suggest that reduced smiling mimicry is specifically linked to blunted affect across the psychosis-risk spectrum, with implications for early identification and intervention.