Statistical Pattern Recognition Reveals Shared Neural Signatures for Displaying and Recognizing Specific Facial Expressions

Abstract

Human neuroimaging and behavioural studies suggest that somatomotor “mirroring” of seen facial expressions may support their recognition. Here we show that viewing specific facial expressions triggers the representation corresponding to that expression in the observer’s brain. Twelve healthy female volunteers underwent two separate fMRI sessions: one where they observed and another where they displayed three types of basic facial expressions (joy, anger and disgust). Pattern classifier based on Bayesian logistic regression was trained to classify facial expressions i) within modality (trained and tested with data recorded while observing or displaying expressions) and ii) between modalities (trained with data recorded while displaying expressions and tested with data recorded while observing the expressions). Cross-modal classification was performed in two ways: with and without functional realignment of the data across observing / displaying conditions. All expressions could be accurately classified within and also across modalities. Brain regions contributing most to cross-modal classification accuracy included primary motor and somatosensory cortices. Functional realignment led to only minor increases in cross-modal classification accuracy for most of the examined ROIs. Substantial improvement was observed in the occipito-ventral components of the core system for facial expression recognition. Altogether these results support the embodied emotion recognition model and show that expression-specific somatomotor neural signatures could support facial expression recognition.

Degenerate pathway for processing smile and other emotional expressions in congenital facial palsy: an hdEEG investigation

“…[20]). This observation is in line with the evidence supporting the reactivation of expression-specific sensorimotor representations during the processing of facial expressions [33]. Altogether, these observations lead to the hypothesis that simulation might be necessary to precisely characterize—from the perceiver's perspective—even subtle instances of others' facial expressions (see [24]).…”

“…In the face of several sources of evidence supporting the hypothesis of a functional reactivation of sensorimotor representations in emotional expression recognition [25–28,30,33] some diverging evidence seems conclusive in holding that this ability does not require sensorimotor simulation.…”

“…Even stronger support for the role of embodiment in emotional processing comes from a recent functional magnetic resonance (fMRI) study by Volynets and colleagues [33]. These authors used a statistical Bayesian pattern recognition technique demonstrating how executed and observed video-clipped facial expressions of joy, anger and disgust are associated with discrete neural signatures in the somatomotor system.…”

Feelings first? Sex differences in affective and cognitive processes in emotion recognition

“…The accurate and fast recognition of emotions from others’ facial expressions is important for effective social interaction and communication (Blair, 2003). It has been proposed that emotions expressed through the face are recognised through a process of embodied simulation (Gallese, 2005), whereby others’ expressions activate corresponding sensorimotor representations in the observer’s brain, and this is supported by recent neuroimaging evidence (Volynets et al, 2020). The embodied response may involve mimicry, which is the subthreshold activation of facial muscles involved in producing the target expression, as demonstrated in electromyography (EMG) studies (Sato et al, 2008).…”

Cerebral Topographies of Perceived and Felt Emotions

“…These cascading evaluative processes may trigger the central and peripheral emotional responses and subsequently also the subjective experience or feeling of emotion (see, e.g., 1,3,27 ). Emotional perception and feelings are associated with activation in overlapping brain regions [28][29][30] . However, an event may trigger emotional states that are either congruent (e.g., seeing a smiling baby makes you happy) or incongruent (e.g., seeing a smiling villain makes you scared) with the event.…”