Lewald Jörg, Riederer Klaus A J, Lentz Tobias, Meister Ingo G
Leibniz Research Centre for Working Environment and Human Factors, Institute for Occupational Physiology at University of Dortmund, Ardeystr. 67, D-44139 Dortmund, Germany.
Eur J Neurosci. 2008 Mar;27(5):1261-70. doi: 10.1111/j.1460-9568.2008.06094.x.
This functional magnetic resonance imaging study was focused on the neural substrates underlying human auditory space perception. In order to present natural-like sound locations to the subjects, acoustic stimuli convolved with individual head-related transfer functions were used. Activation foci, as revealed by analyses of contrasts and interactions between sound locations, formed a complex network, including anterior and posterior regions of temporal lobe, posterior parietal cortex, dorsolateral prefrontal cortex and inferior frontal cortex. The distinct topography of this network was the result of different patterns of activation and deactivation, depending on sound location, in the respective voxels. These patterns suggested different levels of complexity in processing of auditory spatial information, starting with simple left/right discrimination in the regions surrounding the primary auditory cortex, while the integration of information on hemispace and eccentricity of sound may take place at later stages. Activations were identified as being located in regions assigned to both the dorsal and ventral auditory cortical streams, that are assumed to be preferably concerned with analysis of spatial and non-spatial sound features, respectively. The finding of activations also in the ventral stream could, on the one hand, reflect the well-known functional duality of auditory spectral analysis, that is, the concurrent extraction of information based on location (due to the spectrotemporal distortions caused by head and pinnae) and spectral characteristics of a sound source. On the other hand, this result may suggest the existence of shared neural networks, performing analyses of auditory 'higher-order' cues for both localization and identification of sound sources.
这项功能磁共振成像研究聚焦于人类听觉空间感知的神经基础。为了向受试者呈现类似自然的声音位置，使用了与个体头部相关传递函数卷积的声学刺激。通过对声音位置之间的对比和相互作用进行分析揭示的激活焦点形成了一个复杂的网络，包括颞叶的前部和后部区域、顶叶后皮质、背外侧前额叶皮质和额下回。这个网络独特的地形是各个体素中不同激活和失活模式的结果，这取决于声音位置。这些模式表明在处理听觉空间信息时存在不同程度的复杂性，从初级听觉皮质周围区域的简单左右辨别开始，而声音半空间和偏心率信息的整合可能在后期阶段进行。激活被确定位于分配给背侧和腹侧听觉皮质流的区域，这两个区域分别被认为主要与空间和非空间声音特征的分析有关。在腹侧流中也发现激活，一方面可能反映了听觉频谱分析中众所周知的功能二元性，即基于位置（由于头部和耳廓引起的频谱时间失真）和声源频谱特征同时提取信息。另一方面，这个结果可能表明存在共享神经网络，对声源的定位和识别进行听觉“高阶”线索的分析。
