Department of Neurology, Medical College of Wisconsin, Functional Imaging Research Center, Milwaukee, WI 53226, USA.
Neuroimage. 2010 Apr 15;50(3):1202-11. doi: 10.1016/j.neuroimage.2010.01.046. Epub 2010 Jan 22.
The organization of tonotopic fields in human auditory cortex was investigated using functional magnetic resonance imaging. Subjects were presented with stochastically alternating multi-tone sequences in six different frequency bands, centered at 200, 400, 800, 1600, 3200, and 6400 Hz. Two mirror-symmetric frequency gradients were found extending along an anterior-posterior axis from a zone on the lateral aspect of Heschl's gyrus (HG), which responds preferentially to lower frequencies, toward zones posterior and anterior to HG that are sensitive to higher frequencies. The orientation of these two principal gradients is thus roughly perpendicular to HG, rather than parallel as previously assumed. A third, smaller gradient was observed in the lateral posterior aspect of the superior temporal gyrus. The results suggest close homologies between the tonotopic organization of human and nonhuman primate auditory cortex.
采用功能磁共振成像技术研究了人类听觉皮层的音调场组织。研究中向被试呈现了六个不同频带的随机交替多音序列，中心频率分别为 200、400、800、1600、3200 和 6400Hz。发现两个镜像对称的频率梯度沿着从前到后的方向从外侧 Heschl 回（HG）的一个区域延伸，该区域对低频更敏感，而 HG 前后的区域对高频更敏感。这两个主要梯度的方向大致垂直于 HG，而不是像以前假设的那样平行。在颞上回的外侧后部分也观察到了第三个较小的梯度。研究结果表明，人类和非人类灵长类动物听觉皮层的音调组织具有密切的同源性。
