Sebastian Korb | University of Vienna (original) (raw)

Papers by Sebastian Korb

Research paper thumbnail of Obesity, subliminal perception and inhibition: Neuromodulation of the prefrontal cortex

Behavior Research and Therapy, 2019

The prefrontal cortex (PFC) plays a central role in food choice, and may be partly dysfunctional ... more The prefrontal cortex (PFC) plays a central role in food choice, and may be partly dysfunctional in obesity-a condition linked to altered attention and inhibition processes, particularly in response to food-related stimuli. We investigated the role of the PFC in subliminal visual processing and response inhibition to food pictures using anodal, cathodal, or sham transcranial direct current stimulation (tDCS) in a sample of 53 normal weight, overweight, or obese participants. Subliminal processing was measured with a breaking continuous flash suppression task (bCFS), and inhibition with a Go/No-Go task. BMI was included in the analyses as a continuous predictor. Higher BMI was associated with prolonged subliminal processing for both food and nonfood pictures in the bCFS task, and with longer RTs in food Go trials in the Go/No-Go task. Therefore, higher BMI was associated with an attentional bias for food images during supraliminal, but not subliminal visual processing. Moreover, anodal tDCS resulted in shorter detection times in the bCFS task, especially in participants with higher BMI. We conclude that anodal tDCS affects subliminal perception and attentional processes, and speculate that these effects may explain previous reports of reduced craving and food intake after anodal tDCS.

Research paper thumbnail of Face proprioception does not modulate access to visual awareness of emotional faces in a continuous flash suppression paradigm

Consciousness and Cognition, 2017

Research paper thumbnail of Reappraising the voices of wrath

Cognitive reappraisal recruits prefrontal and parietal cortical areas. Because of the near exclus... more Cognitive reappraisal recruits prefrontal and parietal cortical areas. Because of the near exclusive usage in past research of visual stimuli to elicit emotions, it is unknown whether the same neural substrates underlie the reappraisal of emotions induced through other sensory modalities. Here, participants reappraised their emotions in order to increase or decrease their emotional response to angry prosody, or maintained their attention to it in a control condition. Neural activity was monitored with fMRI, and connectivity was investigated by using psychophysiological interaction analyses. A right-sided network encompassing the superior temporal gyrus, the superior temporal sulcus and the inferior frontal gyrus was found to underlie the processing of angry prosody. During reappraisal to increase emotional response, the left superior frontal gyrus showed increased activity and became functionally coupled to right auditory cortices. During reappraisal to decrease emotional response, a network that included the medial frontal gyrus and posterior parietal areas showed increased activation and greater functional connectivity with bilateral auditory regions. Activations pertaining to this network were more extended on the right side of the brain. Although directionality cannot be inferred from PPI analyses, the findings suggest a similar frontoparietal network for the reappraisal of visually and auditorily induced negative emotions.

Research paper thumbnail of Registered Replication Report: Strack, Martin, & Stepper (1988)

According to the facial feedback hypothesis, people’s affective responses can be influenced by th... more According to the facial feedback hypothesis, people’s affective responses can be influenced by their own facial expression (e.g., smiling, pouting), even when their expression did not result from their emotional experiences. For example, Strack, Martin, and Stepper (1988) instructed participants to rate the funniness of cartoons using a pen that they held in their mouth. In line with the facial feedback hypothesis, when participants held the pen with their teeth (inducing a “smile”), they rated the cartoons as funnier than when they held the pen with their lips (inducing a “pout”). This seminal study of the facial feedback hypothesis has not been replicated directly. This Registered Replication Report describes the results of 17 independent direct replications of Study 1 from Strack et al. (1988), all of which followed the same vetted protocol. A meta-analysis of these studies examined the difference in funniness ratings between the “smile” and “pout” conditions. The original Strack et al. (1988) study reported a rating difference of 0.82 units on a 10-point Likert scale. Our meta-analysis revealed a rating difference of 0.03 units with a 95% confidence interval ranging from −0.11 to 0.16.

Research paper thumbnail of Spontaneous Facial Mimicry is Modulated by Joint Attention and Autistic Traits

Autism research : official journal of the International Society for Autism Research, Jan 7, 2015

Joint attention (JA) and spontaneous facial mimicry (SFM) are fundamental processes in social int... more Joint attention (JA) and spontaneous facial mimicry (SFM) are fundamental processes in social interactions, and they are closely related to empathic abilities. When tested independently, both of these processes have been usually observed to be atypical in individuals with autism spectrum conditions (ASC). However, it is not known how these processes interact with each other in relation to autistic traits. This study addresses this question by testing the impact of JA on SFM of happy faces using a truly interactive paradigm. Sixty-two neurotypical participants engaged in gaze-based social interaction with an anthropomorphic, gaze-contingent virtual agent. The agent either established JA by initiating eye contact or looked away, before looking at an object and expressing happiness or disgust. Eye tracking was used to make the agent's gaze behavior and facial actions contingent to the participants' gaze. SFM of happy expressions was measured by Electromyography (EMG) recording ...

Research paper thumbnail of The two sides of spontaneity: Movement onset asymmetries in facial expressions influence social judgments

Journal of Experimental Social Psychology, 2014

Research paper thumbnail of The neuromotor antecedents of emotion regulation in the face

Research paper thumbnail of La régulation des émotions

Research paper thumbnail of Pacifiers disrupt adults’ responses to infants’ emotions

Research shows that pacifiers disrupt infants' mimicry of facial expressions. This experiment exa... more Research shows that pacifiers disrupt infants' mimicry of facial expressions. This experiment examines whether pacifiers interfere with caretakers' ability to mimic infants' emotions. Adults saw photographs of infants with or without a pacifier. When infants had pacifiers, perceivers showed reduced EMG activity to infants' smiles. Smiles of infants using a pacifier were also rated as less happy than smiles depicted without a pacifier. The same pattern was observed for expressions of distress: adults rated infants presented with pacifiers as less sad than infants without pacifiers. We discuss deleterious effects of pacifier use for the perceiver's resonance with a child's emotions.

Research paper thumbnail of Pacifiers Disrupt Adults’ Responses to Infants’ Emotions

Basic and Applied Social Psychology, 2014

Research shows that pacifiers disrupt infants' mimicry of facial expressions. This experiment exa... more Research shows that pacifiers disrupt infants' mimicry of facial expressions. This experiment examines whether pacifiers interfere with caretakers' ability to mimic infants' emotions. Adults saw photographs of infants with or without a pacifier. When infants had pacifiers, perceivers showed reduced EMG activity to infants' smiles. Smiles of infants using a pacifier were also rated as less happy than smiles depicted without a pacifier. The same pattern was observed for expressions of distress: adults rated infants presented with pacifiers as less sad than infants without pacifiers. We discuss deleterious effects of pacifier use for the perceiver's resonance with a child's emotions.

Research paper thumbnail of Gender differences in the neural network of facial mimicry of smiles - An rTMS study

Under theories of embodied emotion, exposure to a facial expression triggers facial mimicry. Faci... more Under theories of embodied emotion, exposure to a facial expression triggers facial mimicry. Facial feedback is then used to recognize and judge the perceived expression. However, the neural bases of facial mimicry and of the use of facial feedback remain poorly understood. Furthermore, gender differences in facial mimicry and emotion recognition suggest that different neural substrates might accompany the production of facial mimicry, and the processing of facial feedback, in men and women. Here, repetitive transcranial magnetic stimulation (rTMS) was applied to the right primary motor cortex (M1), the right primary somatosensory cortex (S1), or, in a control condition, the vertex (VTX). Facial mimicry of smiles and emotion judgments were recorded in response to video clips depicting changes from neutral or angry to happy facial expressions. While in females rTMS over M1 and S1 compared to VTX led to reduced mimicry and, in the case of M1, delayed detection of smiles, there was no effect of TMS condition for males. We conclude that in female participants M1 and S1 play a role in the mimicry and in the use of facial feedback for accurate processing of smiles.

Research paper thumbnail of The Perception and Mimicry of Facial Movements Predict Judgments of Smile Authenticity

PLoS ONE, 2014

The mechanisms through which people perceive different types of smiles and judge their authentici... more The mechanisms through which people perceive different types of smiles and judge their authenticity remain unclear. Here, 19 different types of smiles were created based on the Facial Action Coding System (FACS), using highly controlled, dynamic avatar faces. Participants observed short videos of smiles while their facial mimicry was measured with electromyography (EMG) over four facial muscles. Smile authenticity was judged after each trial. Avatar attractiveness was judged once in response to each avatar's neutral face. Results suggest that, in contrast to most earlier work using static pictures as stimuli, participants relied less on the Duchenne marker (the presence of crow's feet wrinkles around the eyes) in their judgments of authenticity. Furthermore, mimicry of smiles occurred in the Zygomaticus Major, Orbicularis Oculi, and Corrugator muscles. Consistent with theories of embodied cognition, activity in these muscles predicted authenticity judgments, suggesting that facial mimicry influences the perception of smiles. However, no significant mediation effect of facial mimicry was found. Avatar attractiveness did not predict authenticity judgments or mimicry patterns.

Research paper thumbnail of Reappraising the voices of wrath

Social cognitive and affective neuroscience, Jan 11, 2015

Cognitive reappraisal recruits prefrontal and parietal cortical areas. Because of the near exclus... more Cognitive reappraisal recruits prefrontal and parietal cortical areas. Because of the near exclusive usage in past research of visual stimuli to elicit emotions, it is unknown whether the same neural substrates underlie the reappraisal of emotions induced through other sensory modalities. Here, participants reappraised their emotions in order to increase or decrease their emotional response to angry prosody, or maintained their attention to it in a control condition. Neural activity was monitored with fMRI, and connectivity was investigated by using psychophysiological interaction (PPI) analyses. A right-sided network encompassing the superior temporal gyrus (STG), the superior temporal sulcus (STS) and the inferior frontal gyrus (IFG) was found to underlie the processing of angry prosody. During reappraisal to increase emotional response, the left superior frontal gyrus (SFG) showed increased activity and became functionally coupled to right auditory cortices. During reappraisal to...

Research paper thumbnail of The perception and mimicry of facial movements predict judgments of smile authenticity

The mechanisms through which people perceive different types of smiles and judge their authentici... more The mechanisms through which people perceive different types of smiles and judge their authenticity remain unclear. Here, 19 different types of smiles were created based on the Facial Action Coding System (FACS), using highly controlled, dynamic avatar faces. Participants observed short videos of smiles while their facial mimicry was measured with electromyography (EMG) over four facial muscles. Smile authenticity was judged after each trial. Avatar attractiveness was judged once in response to each avatar's neutral face. Results suggest that, in contrast to most earlier work using static pictures as stimuli, participants relied less on the Duchenne marker (the presence of crow's feet wrinkles around the eyes) in their judgments of authenticity. Furthermore, mimicry of smiles occurred in the Zygomaticus Major, Orbicularis Oculi, and Corrugator muscles. Consistent with theories of embodied cognition, activity in these muscles predicted authenticity judgments, suggesting that facial mimicry influences the perception of smiles. However, no significant mediation effect of facial mimicry was found. Avatar attractiveness did not predict authenticity judgments or mimicry patterns.

Research paper thumbnail of Stop laughing! Humor perception with and without expressive suppression

The neurophysiological study of emotion regulation focused on the strategy of reappraisal, i.e. t... more The neurophysiological study of emotion regulation focused on the strategy of reappraisal, i.e. the cognitive reinterpretation of a stimulus. Reappraisal reduces emotional expression, the experience of both negative and positive feelings, and the amplitude of an event-related potential (ERP) – the late positive potential (LPP). In contrast, the strategy of expressive suppression (ES), being the inhibition of emotional expression, has been reported to reduce subjective feelings of positive, but not negative emotion, and was not yet investigated with ERPs. We focused on the LPP to assess the correlates of ES in the context of humor perception. Twenty-two female participants rated sequences of humorous (H) and non-humorous (NH) pictures, while their zygomaticus muscle was recorded. A Spontaneous (SP) condition, in which participants attended naturally to the pictures, resulted in higher ratings of funniness, increased smiling, and increased LPP amplitude for H compared to NH stimuli. An ES condition, in which participants suppressed their facial reactions, resulted in reduced smiling, without affecting subjective ratings. LPP amplitude did not differ between H and NH stimuli during ES, suggesting equal allocation of processing resources to both stimuli. These results suggest that, similarly to reappraisal, ES modifies the way the brain processes positive emotional stimuli.

Research paper thumbnail of Neural architecture of facial expression.

Research paper thumbnail of Motor Commands of Facial Expressions: the Bereitschaftspotential of Posed Smiles.

Electroencephalographic (EEG) premotor potentials with negative polarity like the Bereitschaftspo... more Electroencephalographic (EEG) premotor potentials with negative polarity like the Bereitschaftspotential (BP) are known to precede self-paced voluntary movements of the limbs and other body parts. This is however the first report of such premotor potentials before posed smiles. Scalp EEG was recorded in 16 healthy participants performing self-paced unilateral and bilateral smiles and unilateral finger movements. Amplitudes over six central electrodes and voltage distributions over the entire scalp were compared across conditions at time of EMG-onset, thus focusing on the late BP. Results show the presence of a premotor potential before posed smiles with a later onset, symmetrical bilateral distribution, and smaller amplitude at time of movement-onset, compared to finger movements. Future studies should investigate the BP before various types of emotional and non-emotional facial expressions.

Research paper thumbnail of The neural correlates of the perception, production, and regulation of facial expressions

Research paper thumbnail of Timing and voluntary suppression of facial mimicry to smiling faces in a Go/NoGo task--An EMG study

Biological psychology, Jan 1, 2010

Results obtained with a novel emotional Go/NoGo task allowing the investigation of facial mimicry... more Results obtained with a novel emotional Go/NoGo task allowing the investigation of facial mimicry (FM) during the production and inhibition of voluntary smiles are discussed. Healthy participants were asked to smile rapidly to happy faces and maintain a neutral expression to neutral faces, or the reverse. Replicating and extending previous results, happy faces induced FM, as shown by stronger and faster zygomatic activation to happy than neutral faces in Go trials, and a greater number of false alarms to happy faces in NoGo trials. Facial mimicry effects remained present during participants’ active inhibition of facial movement. Latencies of FM were short with 126–250 ms in Go trials, and 251–375 ms in NoGo trials. The utility of the Go/NoGo task, which allows the assessment of response inhibition in the domain of facial expression by installing strong prepotent motor responses via short stimulus presentation times and a great number of Go trials, is discussed.

Research paper thumbnail of Investigating the production of emotional facial expressions: a combined electroencephalographic (EEG) and electromyographic (EMG) approach

Automatic Face & Gesture …, Jan 1, 2008

Facial expressions are part of emotional reactions. However, humans can voluntarily pose a specif... more Facial expressions are part of emotional reactions. However, humans can voluntarily pose a specific emotional expression without having the corresponding underlying feeling, or voluntarily modify (e.g. reduce or enhance) their spontaneous expression in reaction to an emotional event. Few studies have attempted to distinguish these different processes at the level of the central nervous system (CNS), even though spontaneous and voluntary facial expressions are long thought to rely upon distinct neural circuitries. Here, we review the neural bases of spontaneous and voluntary facial expressions, report the results of a first study assessing the Bereitschaftspotential (BP) before voluntary smiles, and outline a combined EEG/EMG approach for investigating facial expressions at the level of the CNS.

Research paper thumbnail of Obesity, subliminal perception and inhibition: Neuromodulation of the prefrontal cortex

Behavior Research and Therapy, 2019

The prefrontal cortex (PFC) plays a central role in food choice, and may be partly dysfunctional ... more The prefrontal cortex (PFC) plays a central role in food choice, and may be partly dysfunctional in obesity-a condition linked to altered attention and inhibition processes, particularly in response to food-related stimuli. We investigated the role of the PFC in subliminal visual processing and response inhibition to food pictures using anodal, cathodal, or sham transcranial direct current stimulation (tDCS) in a sample of 53 normal weight, overweight, or obese participants. Subliminal processing was measured with a breaking continuous flash suppression task (bCFS), and inhibition with a Go/No-Go task. BMI was included in the analyses as a continuous predictor. Higher BMI was associated with prolonged subliminal processing for both food and nonfood pictures in the bCFS task, and with longer RTs in food Go trials in the Go/No-Go task. Therefore, higher BMI was associated with an attentional bias for food images during supraliminal, but not subliminal visual processing. Moreover, anodal tDCS resulted in shorter detection times in the bCFS task, especially in participants with higher BMI. We conclude that anodal tDCS affects subliminal perception and attentional processes, and speculate that these effects may explain previous reports of reduced craving and food intake after anodal tDCS.

Research paper thumbnail of Face proprioception does not modulate access to visual awareness of emotional faces in a continuous flash suppression paradigm

Consciousness and Cognition, 2017

Research paper thumbnail of Reappraising the voices of wrath

Cognitive reappraisal recruits prefrontal and parietal cortical areas. Because of the near exclus... more Cognitive reappraisal recruits prefrontal and parietal cortical areas. Because of the near exclusive usage in past research of visual stimuli to elicit emotions, it is unknown whether the same neural substrates underlie the reappraisal of emotions induced through other sensory modalities. Here, participants reappraised their emotions in order to increase or decrease their emotional response to angry prosody, or maintained their attention to it in a control condition. Neural activity was monitored with fMRI, and connectivity was investigated by using psychophysiological interaction analyses. A right-sided network encompassing the superior temporal gyrus, the superior temporal sulcus and the inferior frontal gyrus was found to underlie the processing of angry prosody. During reappraisal to increase emotional response, the left superior frontal gyrus showed increased activity and became functionally coupled to right auditory cortices. During reappraisal to decrease emotional response, a network that included the medial frontal gyrus and posterior parietal areas showed increased activation and greater functional connectivity with bilateral auditory regions. Activations pertaining to this network were more extended on the right side of the brain. Although directionality cannot be inferred from PPI analyses, the findings suggest a similar frontoparietal network for the reappraisal of visually and auditorily induced negative emotions.

Research paper thumbnail of Registered Replication Report: Strack, Martin, & Stepper (1988)

According to the facial feedback hypothesis, people’s affective responses can be influenced by th... more According to the facial feedback hypothesis, people’s affective responses can be influenced by their own facial expression (e.g., smiling, pouting), even when their expression did not result from their emotional experiences. For example, Strack, Martin, and Stepper (1988) instructed participants to rate the funniness of cartoons using a pen that they held in their mouth. In line with the facial feedback hypothesis, when participants held the pen with their teeth (inducing a “smile”), they rated the cartoons as funnier than when they held the pen with their lips (inducing a “pout”). This seminal study of the facial feedback hypothesis has not been replicated directly. This Registered Replication Report describes the results of 17 independent direct replications of Study 1 from Strack et al. (1988), all of which followed the same vetted protocol. A meta-analysis of these studies examined the difference in funniness ratings between the “smile” and “pout” conditions. The original Strack et al. (1988) study reported a rating difference of 0.82 units on a 10-point Likert scale. Our meta-analysis revealed a rating difference of 0.03 units with a 95% confidence interval ranging from −0.11 to 0.16.

Research paper thumbnail of Spontaneous Facial Mimicry is Modulated by Joint Attention and Autistic Traits

Autism research : official journal of the International Society for Autism Research, Jan 7, 2015

Joint attention (JA) and spontaneous facial mimicry (SFM) are fundamental processes in social int... more Joint attention (JA) and spontaneous facial mimicry (SFM) are fundamental processes in social interactions, and they are closely related to empathic abilities. When tested independently, both of these processes have been usually observed to be atypical in individuals with autism spectrum conditions (ASC). However, it is not known how these processes interact with each other in relation to autistic traits. This study addresses this question by testing the impact of JA on SFM of happy faces using a truly interactive paradigm. Sixty-two neurotypical participants engaged in gaze-based social interaction with an anthropomorphic, gaze-contingent virtual agent. The agent either established JA by initiating eye contact or looked away, before looking at an object and expressing happiness or disgust. Eye tracking was used to make the agent's gaze behavior and facial actions contingent to the participants' gaze. SFM of happy expressions was measured by Electromyography (EMG) recording ...

Research paper thumbnail of The two sides of spontaneity: Movement onset asymmetries in facial expressions influence social judgments

Journal of Experimental Social Psychology, 2014

Research paper thumbnail of The neuromotor antecedents of emotion regulation in the face

Research paper thumbnail of La régulation des émotions

Research paper thumbnail of Pacifiers disrupt adults’ responses to infants’ emotions

Research shows that pacifiers disrupt infants' mimicry of facial expressions. This experiment exa... more Research shows that pacifiers disrupt infants' mimicry of facial expressions. This experiment examines whether pacifiers interfere with caretakers' ability to mimic infants' emotions. Adults saw photographs of infants with or without a pacifier. When infants had pacifiers, perceivers showed reduced EMG activity to infants' smiles. Smiles of infants using a pacifier were also rated as less happy than smiles depicted without a pacifier. The same pattern was observed for expressions of distress: adults rated infants presented with pacifiers as less sad than infants without pacifiers. We discuss deleterious effects of pacifier use for the perceiver's resonance with a child's emotions.

Research paper thumbnail of Pacifiers Disrupt Adults’ Responses to Infants’ Emotions

Basic and Applied Social Psychology, 2014

Research shows that pacifiers disrupt infants' mimicry of facial expressions. This experiment exa... more Research shows that pacifiers disrupt infants' mimicry of facial expressions. This experiment examines whether pacifiers interfere with caretakers' ability to mimic infants' emotions. Adults saw photographs of infants with or without a pacifier. When infants had pacifiers, perceivers showed reduced EMG activity to infants' smiles. Smiles of infants using a pacifier were also rated as less happy than smiles depicted without a pacifier. The same pattern was observed for expressions of distress: adults rated infants presented with pacifiers as less sad than infants without pacifiers. We discuss deleterious effects of pacifier use for the perceiver's resonance with a child's emotions.

Research paper thumbnail of Gender differences in the neural network of facial mimicry of smiles - An rTMS study

Under theories of embodied emotion, exposure to a facial expression triggers facial mimicry. Faci... more Under theories of embodied emotion, exposure to a facial expression triggers facial mimicry. Facial feedback is then used to recognize and judge the perceived expression. However, the neural bases of facial mimicry and of the use of facial feedback remain poorly understood. Furthermore, gender differences in facial mimicry and emotion recognition suggest that different neural substrates might accompany the production of facial mimicry, and the processing of facial feedback, in men and women. Here, repetitive transcranial magnetic stimulation (rTMS) was applied to the right primary motor cortex (M1), the right primary somatosensory cortex (S1), or, in a control condition, the vertex (VTX). Facial mimicry of smiles and emotion judgments were recorded in response to video clips depicting changes from neutral or angry to happy facial expressions. While in females rTMS over M1 and S1 compared to VTX led to reduced mimicry and, in the case of M1, delayed detection of smiles, there was no effect of TMS condition for males. We conclude that in female participants M1 and S1 play a role in the mimicry and in the use of facial feedback for accurate processing of smiles.

Research paper thumbnail of The Perception and Mimicry of Facial Movements Predict Judgments of Smile Authenticity

PLoS ONE, 2014

The mechanisms through which people perceive different types of smiles and judge their authentici... more The mechanisms through which people perceive different types of smiles and judge their authenticity remain unclear. Here, 19 different types of smiles were created based on the Facial Action Coding System (FACS), using highly controlled, dynamic avatar faces. Participants observed short videos of smiles while their facial mimicry was measured with electromyography (EMG) over four facial muscles. Smile authenticity was judged after each trial. Avatar attractiveness was judged once in response to each avatar's neutral face. Results suggest that, in contrast to most earlier work using static pictures as stimuli, participants relied less on the Duchenne marker (the presence of crow's feet wrinkles around the eyes) in their judgments of authenticity. Furthermore, mimicry of smiles occurred in the Zygomaticus Major, Orbicularis Oculi, and Corrugator muscles. Consistent with theories of embodied cognition, activity in these muscles predicted authenticity judgments, suggesting that facial mimicry influences the perception of smiles. However, no significant mediation effect of facial mimicry was found. Avatar attractiveness did not predict authenticity judgments or mimicry patterns.

Research paper thumbnail of Reappraising the voices of wrath

Social cognitive and affective neuroscience, Jan 11, 2015

Cognitive reappraisal recruits prefrontal and parietal cortical areas. Because of the near exclus... more Cognitive reappraisal recruits prefrontal and parietal cortical areas. Because of the near exclusive usage in past research of visual stimuli to elicit emotions, it is unknown whether the same neural substrates underlie the reappraisal of emotions induced through other sensory modalities. Here, participants reappraised their emotions in order to increase or decrease their emotional response to angry prosody, or maintained their attention to it in a control condition. Neural activity was monitored with fMRI, and connectivity was investigated by using psychophysiological interaction (PPI) analyses. A right-sided network encompassing the superior temporal gyrus (STG), the superior temporal sulcus (STS) and the inferior frontal gyrus (IFG) was found to underlie the processing of angry prosody. During reappraisal to increase emotional response, the left superior frontal gyrus (SFG) showed increased activity and became functionally coupled to right auditory cortices. During reappraisal to...

Research paper thumbnail of The perception and mimicry of facial movements predict judgments of smile authenticity

The mechanisms through which people perceive different types of smiles and judge their authentici... more The mechanisms through which people perceive different types of smiles and judge their authenticity remain unclear. Here, 19 different types of smiles were created based on the Facial Action Coding System (FACS), using highly controlled, dynamic avatar faces. Participants observed short videos of smiles while their facial mimicry was measured with electromyography (EMG) over four facial muscles. Smile authenticity was judged after each trial. Avatar attractiveness was judged once in response to each avatar's neutral face. Results suggest that, in contrast to most earlier work using static pictures as stimuli, participants relied less on the Duchenne marker (the presence of crow's feet wrinkles around the eyes) in their judgments of authenticity. Furthermore, mimicry of smiles occurred in the Zygomaticus Major, Orbicularis Oculi, and Corrugator muscles. Consistent with theories of embodied cognition, activity in these muscles predicted authenticity judgments, suggesting that facial mimicry influences the perception of smiles. However, no significant mediation effect of facial mimicry was found. Avatar attractiveness did not predict authenticity judgments or mimicry patterns.

Research paper thumbnail of Stop laughing! Humor perception with and without expressive suppression

The neurophysiological study of emotion regulation focused on the strategy of reappraisal, i.e. t... more The neurophysiological study of emotion regulation focused on the strategy of reappraisal, i.e. the cognitive reinterpretation of a stimulus. Reappraisal reduces emotional expression, the experience of both negative and positive feelings, and the amplitude of an event-related potential (ERP) – the late positive potential (LPP). In contrast, the strategy of expressive suppression (ES), being the inhibition of emotional expression, has been reported to reduce subjective feelings of positive, but not negative emotion, and was not yet investigated with ERPs. We focused on the LPP to assess the correlates of ES in the context of humor perception. Twenty-two female participants rated sequences of humorous (H) and non-humorous (NH) pictures, while their zygomaticus muscle was recorded. A Spontaneous (SP) condition, in which participants attended naturally to the pictures, resulted in higher ratings of funniness, increased smiling, and increased LPP amplitude for H compared to NH stimuli. An ES condition, in which participants suppressed their facial reactions, resulted in reduced smiling, without affecting subjective ratings. LPP amplitude did not differ between H and NH stimuli during ES, suggesting equal allocation of processing resources to both stimuli. These results suggest that, similarly to reappraisal, ES modifies the way the brain processes positive emotional stimuli.

Research paper thumbnail of Neural architecture of facial expression.

Research paper thumbnail of Motor Commands of Facial Expressions: the Bereitschaftspotential of Posed Smiles.

Electroencephalographic (EEG) premotor potentials with negative polarity like the Bereitschaftspo... more Electroencephalographic (EEG) premotor potentials with negative polarity like the Bereitschaftspotential (BP) are known to precede self-paced voluntary movements of the limbs and other body parts. This is however the first report of such premotor potentials before posed smiles. Scalp EEG was recorded in 16 healthy participants performing self-paced unilateral and bilateral smiles and unilateral finger movements. Amplitudes over six central electrodes and voltage distributions over the entire scalp were compared across conditions at time of EMG-onset, thus focusing on the late BP. Results show the presence of a premotor potential before posed smiles with a later onset, symmetrical bilateral distribution, and smaller amplitude at time of movement-onset, compared to finger movements. Future studies should investigate the BP before various types of emotional and non-emotional facial expressions.

Research paper thumbnail of The neural correlates of the perception, production, and regulation of facial expressions

Research paper thumbnail of Timing and voluntary suppression of facial mimicry to smiling faces in a Go/NoGo task--An EMG study

Biological psychology, Jan 1, 2010

Results obtained with a novel emotional Go/NoGo task allowing the investigation of facial mimicry... more Results obtained with a novel emotional Go/NoGo task allowing the investigation of facial mimicry (FM) during the production and inhibition of voluntary smiles are discussed. Healthy participants were asked to smile rapidly to happy faces and maintain a neutral expression to neutral faces, or the reverse. Replicating and extending previous results, happy faces induced FM, as shown by stronger and faster zygomatic activation to happy than neutral faces in Go trials, and a greater number of false alarms to happy faces in NoGo trials. Facial mimicry effects remained present during participants’ active inhibition of facial movement. Latencies of FM were short with 126–250 ms in Go trials, and 251–375 ms in NoGo trials. The utility of the Go/NoGo task, which allows the assessment of response inhibition in the domain of facial expression by installing strong prepotent motor responses via short stimulus presentation times and a great number of Go trials, is discussed.

Research paper thumbnail of Investigating the production of emotional facial expressions: a combined electroencephalographic (EEG) and electromyographic (EMG) approach

Automatic Face & Gesture …, Jan 1, 2008

Facial expressions are part of emotional reactions. However, humans can voluntarily pose a specif... more Facial expressions are part of emotional reactions. However, humans can voluntarily pose a specific emotional expression without having the corresponding underlying feeling, or voluntarily modify (e.g. reduce or enhance) their spontaneous expression in reaction to an emotional event. Few studies have attempted to distinguish these different processes at the level of the central nervous system (CNS), even though spontaneous and voluntary facial expressions are long thought to rely upon distinct neural circuitries. Here, we review the neural bases of spontaneous and voluntary facial expressions, report the results of a first study assessing the Bereitschaftspotential (BP) before voluntary smiles, and outline a combined EEG/EMG approach for investigating facial expressions at the level of the CNS.