General and specific responsiveness of the amygdala during explicit emotion recognition in females and males
1 MR Centre of Excellence, Medical University of Vienna, Lazarettgasse 14, 1090 Vienna, Austria
2 Institute for Clinical, Biological and Differential Psychology, Faculty of Psychology, University of Vienna, Liebiggasse 5, 1010 Vienna, Austria
3 Department of Psychiatry and Psychotherapy, University of Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany
4 Centre for Biomedical Engineering and Physics, Medical University of Vienna, Währingerstrasse 18, 1090 Vienna, Austria
5 Center of Mind/Brain Sciences, University of Trento, Via delle Regole 101, 38060 Mattarello, Italy
6 Department of Psychiatry, University of Pennsylvania Medical School, 3100 Spruce Street, Philadelphia, USA
BMC Neuroscience 2009, 10:91 doi:10.1186/1471-2202-10-91Published: 4 August 2009
The ability to recognize emotions in facial expressions relies on an extensive neural network with the amygdala as the key node as has typically been demonstrated for the processing of fearful stimuli. A sufficient characterization of the factors influencing and modulating amygdala function, however, has not been reached now. Due to lacking or diverging results on its involvement in recognizing all or only certain negative emotions, the influence of gender or ethnicity is still under debate.
This high-resolution fMRI study addresses some of the relevant parameters, such as emotional valence, gender and poser ethnicity on amygdala activation during facial emotion recognition in 50 Caucasian subjects. Stimuli were color photographs of emotional Caucasian and African American faces.
Bilateral amygdala activation was obtained to all emotional expressions (anger, disgust, fear, happy, and sad) and neutral faces across all subjects. However, only in males a significant correlation of amygdala activation and behavioral response to fearful stimuli was observed, indicating higher amygdala responses with better fear recognition, thus pointing to subtle gender differences. No significant influence of poser ethnicity on amygdala activation occurred, but analysis of recognition accuracy revealed a significant impact of poser ethnicity that was emotion-dependent.
Applying high-resolution fMRI while subjects were performing an explicit emotion recognition task revealed bilateral amygdala activation to all emotions presented and neutral expressions. This mechanism seems to operate similarly in healthy females and males and for both in-group and out-group ethnicities. Our results support the assumption that an intact amygdala response is fundamental in the processing of these salient stimuli due to its relevance detecting function.