Limits...
Sex differences in neural activation to facial expressions denoting contempt and disgust.

Aleman A, Swart M - PLoS ONE (2008)

Bottom Line: Contemptuous faces did not elicit stronger amygdala activation than did disgusted expressions.In addition, the effect of stimulus sex differed for men versus women.Thus, our results suggest a neural basis for sex differences in moral sensitivity regarding hierarchy on the one hand and physical purity on the other.

View Article: PubMed Central - PubMed

Affiliation: BCN Neuroimaging Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. a.aleman@med.umcg.nl

ABSTRACT
The facial expression of contempt has been regarded to communicate feelings of moral superiority. Contempt is an emotion that is closely related to disgust, but in contrast to disgust, contempt is inherently interpersonal and hierarchical. The aim of this study was twofold. First, to investigate the hypothesis of preferential amygdala responses to contempt expressions versus disgust. Second, to investigate whether, at a neural level, men would respond stronger to biological signals of interpersonal superiority (e.g., contempt) than women. We performed an experiment using functional magnetic resonance imaging (fMRI), in which participants watched facial expressions of contempt and disgust in addition to neutral expressions. The faces were presented as distractors in an oddball task in which participants had to react to one target face. Facial expressions of contempt and disgust activated a network of brain regions, including prefrontal areas (superior, middle and medial prefrontal gyrus), anterior cingulate, insula, amygdala, parietal cortex, fusiform gyrus, occipital cortex, putamen and thalamus. Contemptuous faces did not elicit stronger amygdala activation than did disgusted expressions. To limit the number of statistical comparisons, we confined our analyses of sex differences to the frontal and temporal lobes. Men displayed stronger brain activation than women to facial expressions of contempt in the medial frontal gyrus, inferior frontal gyrus, and superior temporal gyrus. Conversely, women showed stronger neural responses than men to facial expressions of disgust. In addition, the effect of stimulus sex differed for men versus women. Specifically, women showed stronger responses to male contemptuous faces (as compared to female expressions), in the insula and middle frontal gyrus. Contempt has been conceptualized as signaling perceived moral violations of social hierarchy, whereas disgust would signal violations of physical purity. Thus, our results suggest a neural basis for sex differences in moral sensitivity regarding hierarchy on the one hand and physical purity on the other.

Show MeSH
Presentation of stimuli in the visual oddball task with emotional faces as distractors and random dot patterns as standards.All stimuli (faces and standards) were presented for 1.9 s. There were 9, 10 or 11 standards after each face presentation (this was randomized). Total duration of the task was approximately 35 min.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2572192&req=5

pone-0003622-g004: Presentation of stimuli in the visual oddball task with emotional faces as distractors and random dot patterns as standards.All stimuli (faces and standards) were presented for 1.9 s. There were 9, 10 or 11 standards after each face presentation (this was randomized). Total duration of the task was approximately 35 min.

Mentions: The task was analogous to the visual oddbal task described by Wang et al. [11], who reported activation of emotional brain areas using such a design with affective pictures. The task was scanned in an event-related design in which the face-stimuli were presented in a pseudo-random fashion (figure 4). The pictures of the emotional faces were presented along with neutral faces as intermittent task-irrelevant distractors during a concurrent visual oddbal task. Faces were shown for 1.9 s. The subjects were presented with random dot patterns created using the face stimuli (“standards”) interspersed with target stimuli (to which they had to react with a button press) and novel distractors (the actual stimuli of interest for our analyses). Thus, the novel distractors consisted of faces expressing disgust or contempt, or neutral faces. The standards were presented for 82% of trials, whereas the other stimuli (target, neutral faces, emotional faces) were presented for 2.33% of trials. There were 9, 10 or 11 standards after each face presentation (this was randomized). The use of standards in an visual odd-ball task may help prevent emotional brain areas from habituating to emotional stimuli. The task for the subject was to press a response button whenever one specific male face (the target) was presented. In each run there were also three short fixation blocks (8.77% of trials), providing a resting state in which the subject looked at a fixation cross presented in the center of the screen.


Sex differences in neural activation to facial expressions denoting contempt and disgust.

Aleman A, Swart M - PLoS ONE (2008)

Presentation of stimuli in the visual oddball task with emotional faces as distractors and random dot patterns as standards.All stimuli (faces and standards) were presented for 1.9 s. There were 9, 10 or 11 standards after each face presentation (this was randomized). Total duration of the task was approximately 35 min.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2572192&req=5

pone-0003622-g004: Presentation of stimuli in the visual oddball task with emotional faces as distractors and random dot patterns as standards.All stimuli (faces and standards) were presented for 1.9 s. There were 9, 10 or 11 standards after each face presentation (this was randomized). Total duration of the task was approximately 35 min.
Mentions: The task was analogous to the visual oddbal task described by Wang et al. [11], who reported activation of emotional brain areas using such a design with affective pictures. The task was scanned in an event-related design in which the face-stimuli were presented in a pseudo-random fashion (figure 4). The pictures of the emotional faces were presented along with neutral faces as intermittent task-irrelevant distractors during a concurrent visual oddbal task. Faces were shown for 1.9 s. The subjects were presented with random dot patterns created using the face stimuli (“standards”) interspersed with target stimuli (to which they had to react with a button press) and novel distractors (the actual stimuli of interest for our analyses). Thus, the novel distractors consisted of faces expressing disgust or contempt, or neutral faces. The standards were presented for 82% of trials, whereas the other stimuli (target, neutral faces, emotional faces) were presented for 2.33% of trials. There were 9, 10 or 11 standards after each face presentation (this was randomized). The use of standards in an visual odd-ball task may help prevent emotional brain areas from habituating to emotional stimuli. The task for the subject was to press a response button whenever one specific male face (the target) was presented. In each run there were also three short fixation blocks (8.77% of trials), providing a resting state in which the subject looked at a fixation cross presented in the center of the screen.

Bottom Line: Contemptuous faces did not elicit stronger amygdala activation than did disgusted expressions.In addition, the effect of stimulus sex differed for men versus women.Thus, our results suggest a neural basis for sex differences in moral sensitivity regarding hierarchy on the one hand and physical purity on the other.

View Article: PubMed Central - PubMed

Affiliation: BCN Neuroimaging Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. a.aleman@med.umcg.nl

ABSTRACT
The facial expression of contempt has been regarded to communicate feelings of moral superiority. Contempt is an emotion that is closely related to disgust, but in contrast to disgust, contempt is inherently interpersonal and hierarchical. The aim of this study was twofold. First, to investigate the hypothesis of preferential amygdala responses to contempt expressions versus disgust. Second, to investigate whether, at a neural level, men would respond stronger to biological signals of interpersonal superiority (e.g., contempt) than women. We performed an experiment using functional magnetic resonance imaging (fMRI), in which participants watched facial expressions of contempt and disgust in addition to neutral expressions. The faces were presented as distractors in an oddball task in which participants had to react to one target face. Facial expressions of contempt and disgust activated a network of brain regions, including prefrontal areas (superior, middle and medial prefrontal gyrus), anterior cingulate, insula, amygdala, parietal cortex, fusiform gyrus, occipital cortex, putamen and thalamus. Contemptuous faces did not elicit stronger amygdala activation than did disgusted expressions. To limit the number of statistical comparisons, we confined our analyses of sex differences to the frontal and temporal lobes. Men displayed stronger brain activation than women to facial expressions of contempt in the medial frontal gyrus, inferior frontal gyrus, and superior temporal gyrus. Conversely, women showed stronger neural responses than men to facial expressions of disgust. In addition, the effect of stimulus sex differed for men versus women. Specifically, women showed stronger responses to male contemptuous faces (as compared to female expressions), in the insula and middle frontal gyrus. Contempt has been conceptualized as signaling perceived moral violations of social hierarchy, whereas disgust would signal violations of physical purity. Thus, our results suggest a neural basis for sex differences in moral sensitivity regarding hierarchy on the one hand and physical purity on the other.

Show MeSH