The functional anatomy of the normal human auditory system: Responses to 0.5 and 4.0 kHz tones at varied intensities
The functional anatomy of the normal human auditory system: Responses to 0.5 and 4.0 kHz tones at varied intensities
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DOI：
10.1093/cercor/9.1.65
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发表时间：
1999-01-01
期刊：
影响因子：
3.7
通讯作者：
Burkard, RF
中科院分区：
文献类型：
--
作者：
Lockwood, AH;Salvi, RJ;Burkard, RF
大多数听觉系统的功能成像研究都采用了复杂的刺激。我们使用正电子发射断层扫描来绘制右耳在30,50,70和90db HL下呈现的0.5和4.0 kHz正弦波音调的神经反应，发现在一个复杂的神经网络中激活了传统上与听觉系统相关的元素，以及非传统的部位，如后扣带皮层。在低刺激强度时，扣带活动最大，这表明它可能具有增益控制中心的功能。在右侧颞叶，最大反应的位置随刺激的强度而变化，但不随刺激的频率而变化。在左颞叶，有证据表明音调组织：左侧初级听觉皮层外侧的一个部位被两种音调同样激活，而初级听觉皮层的另一个部位对更高的频率更敏感。幕下激活位于受刺激耳的对侧，包括外侧小脑、外侧桥状被、中脑和内侧膝状。与基于耳蜗膜力学的预测相反，在每种强度下，4.0 kHz的刺激比0.5 kHz的刺激对大脑的激活更有效。
Most functional imaging studies of the auditory system have employed complex stimuli. We used positron emisssion tomography to map neural responses to 0.5 and 4.0 kHz sine-wave tones presented to the right ear at 30, 50, 70 and 90 dB HL and found activation in a complex neural network of elements traditionally associated with the auditory system as well as non-traditional sites such as the posterior cingulate cortex. Cingulate activity was maximal at low stimulus intensities, suggesting that it may function as a gain control center. In the right temporal lobe, the location of the maximal response varied with the intensity, but not with the frequency of the stimuli. In the left temporal lobe, there was evidence for tonotopic organization: a site lateral to the left primary auditory cortex was activated equally by both tones while a second site in primary auditory cortex was more responsive to the higher frequency. Infratentorial activations were contralateral to the stimulated ear and included the lateral cerebellum, the lateral pontine tegmentum, the midbrain and the medial geniculate. Contrary to predictions based on cochlear membrane mechanics, at each intensity, 4.0 kHz stimuli were more potent activators of the brain than the 0.5 kHz stimuli.