Tervaniemi M, Medvedev S V, Alho K, Pakhomov S V, Roudas M S, Van Zuijen T L, Näätänen R
Cognitive Brain Research Unit, Department of Psychology, University of Helsinki, Finland.
Hum Brain Mapp. 2000 Jun;10(2):74-9. doi: 10.1002/(SICI)1097-0193(200006)10:2<74::AID-HBM30>3.0.CO;2-2.
Previous positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) studies show that during attentive listening, processing of phonetic information is associated with higher activity in the left auditory cortex than in the right auditory cortex while the opposite is true for musical information. The present PET study determined whether automatically activated neural mechanisms for phonetic and musical information are lateralized. To this end, subjects engaged in a visual word classification task were presented with phonetic sound sequences consisting of frequent (P = 0.8) and infrequent (P = 0.2) phonemes and with musical sound sequences consisting of frequent (P = 0.8) and infrequent (P = 0.2) chords. The phonemes and chords were matched in spectral complexity as well as in the magnitude of frequency difference between the frequent and infrequent sounds (/e/ vs. /o/; A major vs. A minor). In addition, control sequences, consisting of either frequent (/e/; A major) or infrequent sounds (/o/; A minor) were employed in separate blocks. When sound sequences consisted of intermixed frequent and infrequent sounds, automatic phonetic processing was lateralized to the left hemisphere and musical to the right hemisphere. This lateralization, however, did not occur in control blocks with one type of sound (frequent or infrequent). The data thus indicate that automatic activation of lateralized neuronal circuits requires sound comparison based on short-term sound representations.
先前的正电子发射断层扫描（PET）和功能磁共振成像（fMRI）研究表明，在专注聆听过程中，语音信息的处理与左听觉皮层的活动增强有关，而右听觉皮层的活动则相对较弱；而对于音乐信息，情况则相反。本PET研究旨在确定语音和音乐信息的自动激活神经机制是否存在偏侧化。为此，让参与视觉单词分类任务的受试者分别听由频繁出现（P = 0.8）和不频繁出现（P = 0.2）音素组成的语音序列，以及由频繁出现（P = 0.8）和不频繁出现（P = 0.2）和弦组成的音乐序列。音素和弦在频谱复杂性以及频繁和不频繁声音之间的频率差异幅度上进行了匹配（/e/ 与 /o/；A大调与A小调）。此外，在单独的组块中使用了由频繁出现的声音（/e/；A大调）或不频繁出现的声音（/o/；A小调）组成的控制序列。当声音序列由频繁和不频繁的声音混合组成时，自动语音处理偏侧于左半球，而音乐处理偏侧于右半球。然而，在只有一种类型声音（频繁或不频繁）的控制组块中并未出现这种偏侧化。因此，数据表明，偏侧化神经元回路的自动激活需要基于短期声音表征的声音比较。
