Amplitopicity of the human auditory cortex: An fMRI study
Amplitopicity of the human auditory cortex: An fMRI study
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DOI：
10.1006/nimg.2002.1133
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发表时间：
2002-10-01
期刊：
影响因子：
5.7
通讯作者：
Schulte, AC
中科院分区：
文献类型：
--
作者：
Bilecen, D;Seifritz, E;Schulte, AC
而专门的频率编码模式在人类听觉皮层被普遍接受，称为tonotopicity，强度编码的类似原则-amplitopicity-有争议。本功能磁共振成像研究描述了在不同声压水平（SPL）下，激活簇在包括颞横回（TTG）在内的颞平面上的激活体积和空间分布的关系。在1.5T条件下，对9名无听力缺陷的健康受试者进行了回波平面成像技术研究。在70、82和90 dB的三个SPL下，应用具有1000 Hz频率的5 Hz脉冲正弦音调的矩形波串刺激范例。功能数据集的线性交叉相关分析（相关系数> 0.3对应于P < 0.08）显示双侧BOLD反应在。9名受试者的听觉皮层对较高声压水平的激活量适度增加。随着声压的增加，皮层激活的二维漂移被观察到（a）从腹侧到背侧边缘和（B）从外侧到内侧部分的TTG。因此，这种侧-中漂移模仿了频率编码神经元的普遍接受的音调映射原理。这项研究表明，强度编码神经元簇的振幅分布模式的存在，部分类似于频率编码神经元的tonotopic分布。这一发现必须整合到对听觉组织的理解中，以解释更高的听觉功能，如声音感知或言语。(C)2002 Elsevier Science（美国）。
Whereas specialized frequency-encoding patterns in the human auditory cortex are generally accepted, termed tonotopicity, a similar principle of intensity encoding-amplitopicity-is debated controversially. This functional magnetic resonance imaging study describes the relationship of the activation volume and the spatial distribution of activated clusters under different sound pressure levels (SPL) across the temporal plane including the transverse temporal gyrus (TTG). Nine healthy subjects with no hearing deficiencies were investigated using an echo-planar imaging technique at 1.5 T. A boxcar stimulation paradigm was applied with a 5-Hz pulsed sine tone of 1000 Hz frequency at three SPLs of 70, 82, and 90 dB. Linear cross-correlation analysis (correlation coefficient > 0.3 corresponding to P < 0.08) of the functional data set revealed bilateral BOLD response within the. auditory cortex of the nine subjects with moderate increase of activation volume for higher sound pressure levels. With increasing sound pressure a two-dimensional drift of cortical activation was observed (a) from the ventral to the dorsal edge and (b) from lateral to medial parts of TTG. This latero-medial drift therefore mimics the well-accepted principle of tonotopy for frequency-encoding neurons. This study demonstrates the existence of an amplitopic pattern of intensity-encoding neuronal clusters that in part resembles the tonotopic distribution of frequency-encoding neurons. This finding has to be integrated into the understanding of the auditory organization for the interpretation of higher auditory functions such as sound perception or speech. (C) 2002 Elsevier Science (USA).