Neuroimaging Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
PLoS One. 2011 May 9;6(5):e19501. doi: 10.1371/journal.pone.0019501.
Alexithymia, a condition characterized by deficits in interpreting and regulating feelings, is a risk factor for a variety of psychiatric conditions. Little is known about how alexithymia influences the processing of emotions in music and speech. Appreciation of such emotional qualities in auditory material is fundamental to human experience and has profound consequences for functioning in daily life. We investigated the neural signature of such emotional processing in alexithymia by means of event-related potentials.
Affective music and speech prosody were presented as targets following affectively congruent or incongruent visual word primes in two conditions. In two further conditions, affective music and speech prosody served as primes and visually presented words with affective connotations were presented as targets. Thirty-two participants (16 male) judged the affective valence of the targets. We tested the influence of alexithymia on cross-modal affective priming and on N400 amplitudes, indicative of individual sensitivity to an affective mismatch between words, prosody, and music. Our results indicate that the affective priming effect for prosody targets tended to be reduced with increasing scores on alexithymia, while no behavioral differences were observed for music and word targets. At the electrophysiological level, alexithymia was associated with significantly smaller N400 amplitudes in response to affectively incongruent music and speech targets, but not to incongruent word targets.
Our results suggest a reduced sensitivity for the emotional qualities of speech and music in alexithymia during affective categorization. This deficit becomes evident primarily in situations in which a verbalization of emotional information is required.
述情障碍是一种以解读和调节情绪能力缺陷为特征的病症，是多种精神疾病的风险因素。述情障碍如何影响音乐和言语中的情绪处理，目前还知之甚少。对听觉材料中这种情绪特征的欣赏是人类体验的基础，对日常生活中的功能有深远的影响。我们通过事件相关电位研究了述情障碍中这种情绪处理的神经特征。
在两种条件下，在视觉单词启动词之后呈现情感一致或不一致的情感音乐和言语韵律作为目标。在另外两种条件下，情感音乐和言语韵律作为启动词，带有情感内涵的视觉呈现的单词作为目标。32 名参与者（16 名男性）判断目标的情感效价。我们测试了述情障碍对跨模态情感启动和 N400 振幅的影响，N400 振幅表示个体对单词、韵律和音乐之间情感不匹配的敏感性。我们的结果表明，随着述情障碍得分的增加，韵律目标的情感启动效应趋于降低，而音乐和单词目标则没有观察到行为差异。在电生理水平上，述情障碍与对情感不一致的音乐和言语目标的 N400 振幅显著减小相关，但对情感不一致的单词目标没有影响。
我们的结果表明，在情感分类过程中，述情障碍者对言语和音乐的情感特征的敏感性降低。这种缺陷主要在需要言语化情感信息的情况下才会显现出来。
