Blocking facial mimicry during binocular rivalry modulates visual awareness of faces with a neutral expression

Abstract

Several previous studies have interfered with the observer’s facial mimicry during a variety of facial expression recognition tasks providing evidence in favor of the role of facial mimicry and sensorimotor activity in emotion processing. In this theoretical context, a particularly intriguing facet has been neglected, namely whether blocking facial mimicry modulates conscious perception of facial expressions of emotions. To address this issue, we used a binocular rivalry paradigm, in which two dissimilar stimuli presented to the two eyes alternatingly dominate conscious perception. On each trial, female participants (N = 32) were exposed to a rivalrous pair of a neutral and a happy expression of the same individual through anaglyph glasses in two conditions: in one, they could freely use their facial mimicry, in the other they had to keep a chopstick between their lips, constraining the mobility of the zygomatic muscle and producing ‘noise’ for sensorimotor simulation. We found that blocking facial mimicry affected the perceptual dominance in terms of cumulative time favoring neutral faces, but it did not change the time before the first dominance was established. Taken together, our results open a door to future investigation of the intersection between sensorimotor simulation models and conscious perception of emotional facial expressions.

Mask-wearing selectivity alters observers’ face perception

“…Particularly, manipulation of body posture or hand posture was found to modulate tactile perception (Longo, 2017 ) and visual perception of size (Kim et al, 2021 ), letters (Barnett-Cowan et al, 2015 ) and faces (Barnett-Cowan et al, 2015 ; Davidenko & Flusberg, 2012 ). In the domain of face perception, previous research has focused on the effect of somatosensory stimulation (via enforced face pose or brain stimulation) on emotion recognition (Borgomaneri et al, 2020 ; Niedenthal, 2007 ; Oberman et al, 2007 ; Quettier et al, 2021 ). Across these studies, a reduced emotion recognition ability was identified when participants could not mimic facial expression, or when a TMS was delivered to their somatosensory cortex (Pitcher et al, 2008 ).…”

Visual awareness of others’ facial expressions during binocular rivalry under tactile stimulation on the viewer’s face

“…To note, differently from the continuous flash suppression paradigm, for instance implemented in Korb et al (2017), BR allows to monitor modulations of both access and stabilization in consciousness of facial expressions. Indeed, psychological processes involved during the BR have been previously characterized considering three measures (Quettier et al, 2021). First, the initial percept (IP) is defined as the first dominant rivaling stimulus.…”

“…In this study, we specifically hypothesize that recruiting somatosensory representations will facilitate conscious experiencing of happy facial expressions, in terms of conscious stabilization (i.e., dominance, CT) over neutral facial expressions. The main reason for this choice derives from the results of our previous study (Quettier et al, 2021), in which the participants' facial mimicry was manipulated during a task similar to the one planned here. The results highlighted that this type of manipulation has an impact on the conscious processing of facial expressions during the stabilization phase of the content in consciousness (as indicated by the modulation of the cumulative time as a function of the mimicry manipulation).…”

“…Data reduction. CTs will be computed by summing the perceptual duration for each of neutral and happy/mustache percept segments during a trial, as in our recent study (Quettier et al, 2021).…”

Altering Facial Movements Abolishes Neural Mirroring of Facial Expressions

“…Manipulations of facial mimicry have been shown to influence a wide range of abilities, including perception and categorization of other people's facial expressions (Lewis & Dunn, 2017;Quettier et al, 2021;Wood et al, 2016a); representations of facial expressions in visual working memory (Sessa et al, 2018), or semantic processing of emotional language (Davis et al, 2015). In addition, interfering with facial movements changes neural responses to emotion expressions.…”