RESUMEN

Actions are rarely devoid of emotional content. Thus, a more complete picture of the neural mechanisms underlying the mental simulation of observed actions requires more research using emotion information. The present study used high-density electroencephalography to investigate mental simulation associated with facial emotion categorisation. Alpha-mu rhythm modulation was measured at each frequency, from 8 Hz to 13 Hz, to infer the degree of sensorimotor simulation. Results suggest the sensitivity of the sensorimotor activity to emotional information, because (1) categorising static images of neutral faces as happy or sad was associated with stronger suppression in the central region than categorising clearly happy faces, (2) there was preliminary evidence indicating that the strongest suppression in the central region was in response to neutral faces, followed by sad and then happy faces and (3) in the control task, which required categorising images with the head oriented right, left, or forward as right or left, differences between conditions showed a pattern more indicative of task difficulty rather than sensorimotor engagement. Dissociable processing of emotional information in facial expressions and directionality information in head orientations was further captured in beta band activity (14-20 Hz). Stronger mu suppression to neutral faces indicates that sensorimotor simulation extends beyond crude motor mimicry. We propose that mu rhythm responses to facial expressions may serve as a biomarker for empathy circuit activation. Future research should investigate whether atypical or inconsistent mu rhythm responses to facial expressions indicate difficulties in understanding or sharing emotions.

RESUMEN

Until recently, for almost 3 years, we used face masks to protect against COVID-19. Face masks disrupted our perception of socially relevant information, and impacted our social judgements as a result of the new social norms around wearing masks imposed by the pandemic. To shed light on such pandemic-induced changes in social emotional processes, Calbi et al. analysed data from an Italian sample collected in Spring 2020. They assessed valence, social distance and physical distance ratings for neutral, happy and angry male and female faces covered with a scarf or a mask. A year later, we used the same stimuli to investigate the same measures in a Turkish sample. We found that females attributed more negative valence ratings than males to angry faces, and that angry and neutral faces of females were rated more negatively than those of males. Scarf stimuli were evaluated more negatively in terms of valence. Participants attributed greater distance to more negative faces (angry > neutral > happy) and to scarf than the mask stimuli. Also, females attributed greater social and physical distance than males. These results may be explained by gender-stereotypic socialisation processes, and changes in people's perception of health behaviours during the pandemic.

Asunto(s)

COVID-19 , Masculino , Humanos , Femenino , COVID-19/epidemiología , Emociones , Ira , Felicidad , Juicio , Expresión Facial

RESUMEN

The mirror neuron network (MNN) has been proposed as a neural substrate of action understanding. Electroencephalography (EEG) mu suppression has commonly been studied as an index of MNN activity during execution and observation of hand and finger movements. However, in order to establish its role in higher order processes, such as recognizing and sharing emotions, more research using social emotional stimuli is needed. The current study aims to contribute to our understanding of the sensitivity of mu suppression to facial expressions. Modulation of the mu and occipital alpha (8-13 Hz) rhythms was calculated in 22 participants while they observed dynamic video stimuli, including emotional (happy and sad) and neutral (mouth opening) facial expressions, and non-biological stimulus (kaleidoscope pattern). Across the four types of stimuli, only the neutral face was associated with a significantly stronger mu suppression than the non-biological stimulus. Occipital alpha suppression was significantly greater in the non-biological stimulus than all the face conditions. Source estimation standardized low resolution electromagnetic tomography (sLORETA) analysis comparing the neural sources of mu/alpha modulation between neutral face and non-biological stimulus showed more suppression in the central regions, including the supplementary motor and somatosensory areas, than the more posterior regions. EEG and source estimation results may indicate that reduced availability of emotional information in the neutral face condition requires more sensorimotor engagement in deciphering emotion-related information than the full-blown happy or sad expressions that are more readily recognized.