Audio and visual speech emotion activates the left pre-supplementary motor area

Abstract

Sensorimotor brain areas have been implicated in the recognition of emotion expressed on the face and through non-verbal vocalizations. However, no previous study has assessed whether sensorimotor cortices are recruited during the perception of emotion in speech, a signal that includes both audio (speech sounds) and visual (facial speech movements) components. To address this gap in the literature, we recruited 24 participants to listen to speech clips expressed in a way that was either a happy, sad, or neutral. These stimuli were also presented in one of three modalities: audio-only (hearing the voice but not seeing the face), video-only (seeing the face but not hearing the voice), or audiovisual. Brain activity was recorded using electroencephalography, subjected to independent component analysis, and source-localized. We found that the left pre-supplementary motor area was more active in response to happy and sad stimuli than neutral stimuli, as indexed by greater mu event-related desynchronization. This effect did not differ by the sensory modality of the stimuli. Activity levels in other sensorimotor brain areas did not differ by emotion, although they were greatest in response to visual-only and audiovisual stimuli. One possible explanation for the pre-SMA result is that this brain area may actively support speech emotion recognition by using our extensive experience expressing emotion to generate sensory predictions that in turn guide our perception.

Human mirror neuron system responsivity to unimodal and multimodal presentations of action

“…However, the perception of speech is not very well suited to elicit hMNS activity because of the rich semantic support provided by the ventral stream and the stereotypy of phonology in a given language. Better auditory candidates to consider would be perception of isolated syllables (Crawcour et al, 2009), vocal emotion (Rovetti et al, 2021), singing and/or music (Bagert et al, 2006;McGarry et al, 2015;Molnar-Szakacs & Overy, 2006;Russo, 2020). These auditory stimuli are semantically abstract, which may give rise to compensatory involvement of the hMNS to support action understanding.…”