NeuroImage Nord, Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Neuroimage. 2012 Jan 16;59(2):1765-71. doi: 10.1016/j.neuroimage.2011.08.046. Epub 2011 Aug 26.
Amygdala involvement in visual emotional processing has been unequivocally established, but the amygdala's participation in auditory emotional processing is less clear. In a previous functional magnetic resonance imaging study (Klinge et al., 2010) we investigated the amygdala's role in auditory emotional processing in blind and sighted humans. We observed stronger amygdala responses to auditory emotional stimuli in the blind who were also better at discriminating emotional stimuli. Importantly, inter-individual differences in this skill correlated with amygdala activation. While these data suggested that the amygdala serves the dominant sensory modality for emotional perception, we could not rule out possible influences of use-dependent training effects. To disambiguate between plastic changes due to deprivation or training we now studied professional actors who have undergone extensive perceptual and expressive auditory emotional trainings but no sensory deprivation. Actors showed emotion discrimination skills comparable to those of blind individuals. However, in contrast to blind volunteers they lacked increased amygdala activations. Surprisingly, actors selectively rated angry stimuli as less intense than control participants, paralleled by a down-regulation of amygdala responses via the anterior cingulate cortex. Taken together, the data from our two studies suggest that enhanced amygdala responses in the blind are mainly due to deprivation-induced plasticity, as highly trained actors who possess the same excellent emotion discrimination skills as the blind did not show these responses. It is also conceivable that the actors' training requires a more professional and controlled dealing with the emotional stimuli, resulting in a down-regulation of affective experience and accompanying amygdala responses.
杏仁核参与视觉情绪处理已得到明确证实，但杏仁核在听觉情绪处理中的参与尚不明确。在之前的一项功能磁共振成像研究（Klinge 等人，2010 年）中，我们研究了杏仁核在盲人和视力正常的人听觉情绪处理中的作用。我们观察到，盲人大脑中对听觉情绪刺激的反应更强，而且他们对情绪刺激的辨别能力也更强。重要的是，这种技能的个体间差异与杏仁核的激活有关。虽然这些数据表明杏仁核是情绪感知的主导感觉模态，但我们不能排除可能的使用依赖性训练效应的影响。为了区分因剥夺或训练而导致的可塑性变化，我们现在研究了专业演员，他们接受了广泛的感知和表达性听觉情绪训练，但没有感官剥夺。演员表现出的情绪辨别能力与盲人相当。然而，与盲人志愿者不同的是，他们的杏仁核激活没有增加。令人惊讶的是，演员们选择性地认为愤怒的刺激强度低于对照组，同时通过前扣带皮层调节杏仁核的反应。综合这两项研究的数据表明，盲人增强的杏仁核反应主要归因于剥夺诱导的可塑性，因为接受过同样出色的情绪辨别训练的专业演员并没有表现出这些反应。也可以想象，演员的训练需要更专业和受控的处理情绪刺激，从而导致情感体验和伴随的杏仁核反应的下调。
