Pictures of disgusting foods and disgusted facial expressions suppress the tongue motor cortex.
The tongue holds a unique role in gustatory disgust. However, it is unclear whether the tongue representation in the motor cortex (tM1) is affected by the sight of distaste-related stimuli. Using transcranial magnetic stimulation (TMS) in healthy humans, we recorded tongue motor-evoked potentials (MEPs) as an index of tM1 cortico-hypoglossal excitability. MEPs were recorded while participants viewed pictures associated with gustatory disgust and revulsion (i.e. rotten foods and faces expressing distaste), non-oral-related disgusting stimuli (i.e. invertebrates like worms) and control stimuli. We found that oral-related disgust pictures suppressed tM1 cortico-hypoglossal output. This tM1 suppression was predicted by interindividual differences in disgust sensitivity. No similar suppression was found for disgusting invertebrates or when MEPs were recorded from a control muscle. These findings suggest that revulsion-eliciting food pictures trigger anticipatory inhibition mechanisms, possibly preventing toxin swallowing and contamination. A similar suppression is elicited when viewing distaste expressions, suggesting vicarious motor inhibition during social perception of disgust. Our study suggests an avoidant-defensive mechanism in human cortico-hypoglossal circuits and its 'resonant' activation in the vicarious experience of others' distaste. These findings support a role for the motor system in emotion-driven motor anticipation and social cognition.
Wolfson Centre for Clinical and Cognitive Neuroscience, School of Psychology, Bangor University, Bangor Gwynedd LL57 2DG, UK.|School of Psychology, University of Tasmania, Hobart, Tasmania 7000, Australia.
Carmelo M
CM
Vicario
Wolfson Centre for Clinical and Cognitive Neuroscience, School of Psychology, Bangor University, Bangor Gwynedd LL57 2DG, UK.
Robert D
RD
Rafal
Department of Psychology and Center for Studies and Research in Cognitive Neuroscience, University of Bologna, Cesena Campus, Cesena 47521, Italy.|IRCCS Fondazione Santa Lucia, Roma 00179, Italy.
Sara
S
Borgomaneri
Department of Psychology and Center for Studies and Research in Cognitive Neuroscience, University of Bologna, Cesena Campus, Cesena 47521, Italy.
Riccardo
R
Paracampo
School of Psychology, The University of Queensland, McElwain Building, St Lucia Campus, Brisbane 4072, Australia.
Ada
A
Kritikos
Department of Psychology and Center for Studies and Research in Cognitive Neuroscience, University of Bologna, Cesena Campus, Cesena 47521, Italy.|IRCCS Fondazione Santa Lucia, Roma 00179, Italy.
Alessio
A
Avenanti
D000328:Adult; D001362:Avoidance Learning / Q000502:physiology; D004576:Electromyography; D004644:Emotions / Q000502:physiology*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005149:Facial Expression; D005260:Female; D005518:Food Preferences / Q000502:physiology*; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D013649:Taste / Q000502:physiology*; D014059:Tongue / Q000294:innervation*; D050781:Transcranial Magnetic Stimulation
disgust; emotion recognition; motor-evoked potentials; tongue motor area; transcranial magnetic stimulation