Medial prefrontal activity at encoding determines enhanced recognition of threatening faces after 1.5 years

Abstract

Studies demonstrated that faces with emotional expressions are better remembered than neutral faces. However, whether the memory advantage persists over years and which neural systems mediate such an effect remains unknown. We investigated recognition of incidentally encoded faces with angry, fearful, happy, sad and neutral expressions over >1.5 years (N=102). Both univariate and multivariate analyses showed that faces with threatening expressions (angry, fearful) were better recognized than happy and neutral faces. Comparison with immediate recognition indicated that this effect was driven by decreased recognition of non-threatening faces. Functional magnetic resonance imaging (fMRI) data was acquired during encoding and results revealed that differential neural encoding in the right ventromedial prefrontal/orbitofrontal cortex neurally mediated the long-term recognition advantage for threatening faces. Our study provides the evidence that threatening facial expressions lead to persistent face recognition over periods of >1.5 years and encoding-related activity in the ventromedial prefrontal cortex may underlie preserved recognition.