Faculty of Psychology, Vita-Salute San Raffaele University, 20132 Milan, Italy.
Proc Natl Acad Sci U S A. 2010 Mar 9;107(10):4758-63. doi: 10.1073/pnas.0909074107. Epub 2010 Feb 22.
In adults, specific neural systems with right-hemispheric weighting are necessary to process pitch, melody, and harmony as well as structure and meaning emerging from musical sequences. It is not known to what extent the specialization of these systems results from long-term exposure to music or from neurobiological constraints. One way to address this question is to examine how these systems function at birth, when auditory experience is minimal. We used functional MRI to measure brain activity in 1- to 3-day-old newborns while they heard excerpts of Western tonal music and altered versions of the same excerpts. Altered versions either included changes of the tonal key or were permanently dissonant. Music evoked predominantly right-hemispheric activations in primary and higher order auditory cortex. During presentation of the altered excerpts, hemodynamic responses were significantly reduced in the right auditory cortex, and activations emerged in the left inferior frontal cortex and limbic structures. These results demonstrate that the infant brain shows a hemispheric specialization in processing music as early as the first postnatal hours. Results also indicate that the neural architecture underlying music processing in newborns is sensitive to changes in tonal key as well as to differences in consonance and dissonance.
在成年人中，特定的右侧大脑半球偏重的神经系统对于处理音高、旋律和和声以及音乐序列中出现的结构和意义是必要的。这些系统的专业化是长期接触音乐的结果还是神经生物学限制的结果尚不清楚。解决这个问题的一种方法是研究这些系统在出生时的功能，此时听觉体验最小。我们使用功能磁共振成像来测量 1 至 3 天大的新生儿的大脑活动，同时让他们听西方音调音乐的片段和同一片段的变化版本。变化的版本包括调式的改变或永久不和谐。音乐引起了初级和高级听觉皮层的主要右侧大脑半球激活。在呈现变化的片段时，右侧听觉皮层的血流动力学反应明显降低，而左侧额下回和边缘结构出现了激活。这些结果表明，婴儿大脑在出生后的头几个小时就表现出了对音乐处理的半球专业化。结果还表明，新生儿音乐处理的神经结构对调式的变化以及和谐与不和谐的差异很敏感。
