Music and Neuroimaging Laboratory, Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
Front Psychol. 2010 Nov 11;1:193. doi: 10.3389/fpsyg.2010.00193.
The neural basis of the human brain's ability to discriminate pitch has been investigated by functional neuroimaging and the study of lesioned brains, indicating the critical importance of right and left Heschl's gyrus (HG) in pitch perception. Nonetheless, there remains some uncertainty with regard to localization and lateralization of pitch discrimination, partly because neuroimaging results do not allow us to draw inferences about the causality. To address the problem of causality in pitch discrimination functions, we used transcranial direct current stimulation to downregulate (via cathodal stimulation) and upregulate (via anodal stimulation) excitability in either left or right auditory cortex and measured the effect on performance in a pitch discrimination task in comparison with sham stimulation. Cathodal stimulation of HG on the left and on the right hemispheres adversely affected pitch discrimination in comparison to sham stimulation, with the effect on the right being significantly stronger than on the left. Anodal stimulation on either side had no effect on performance in comparison to sham. Our results indicate that both left and right HG are causally involved in pitch discrimination, although the right auditory cortex might be a stronger contributor.
人类大脑辨别音高的能力的神经基础已经通过功能神经影像学和损伤大脑的研究进行了研究，表明右和左 Heschl 回（HG）在音高感知中至关重要。尽管如此，在音高辨别定位和侧化方面仍然存在一些不确定性，部分原因是神经影像学结果不允许我们推断因果关系。为了解决音高辨别功能中的因果关系问题，我们使用经颅直流电刺激来调节（通过阴极刺激）和调节（通过阳极刺激）左或右听觉皮层的兴奋性，并在与假刺激的比较中测量对音高辨别任务表现的影响。与假刺激相比，左和右半球 HG 的阴极刺激对音高辨别有不利影响，右侧的影响明显强于左侧。与假刺激相比，任一侧的阳极刺激对性能均无影响。我们的结果表明，左和右 HG 都与音高辨别有关，尽管右听觉皮层可能是更强的贡献者。
