Generalizable dimensions of human cortical auditory processing of speech in natural soundscapes: A data-driven ultra high field fMRI approach
Generalizable dimensions of human cortical auditory processing of speech in natural soundscapes: A data-driven ultra high field fMRI approach
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DOI：
10.1016/j.neuroimage.2021.118106
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发表时间：
2021-06-03
期刊：
影响因子：
5.7
通讯作者：
Rieger，Jochem W.
中科院分区：
文献类型：
--
作者：
Boos，Morit;Lucke，Jorg;Rieger，Jochem W.
自然声环境中的语音理解依赖于听觉系统从多个声源重叠的复杂声信号中提取语音信息的能力。本研究利用数据驱动的建模方法对声音进行表征，并分析了参与者在听电影原声时录制的超高场功能磁共振成像（fMRI）记录，揭示了自然声景中语音在多个尺度上的规范处理。我们的研究表明，在功能层面上，人类皮层对自然声景中语音的神经元处理可以是惊人的低维，突出了听觉系统在看似复杂的任务中的功能效率。特别是，我们发现一个由颞叶听觉处理的三个功能维度组成的模型在参与者的fMRI活动中是共享的。我们进一步证明，这三个功能维度是在解剖学上重叠的网络中实现的，这些网络处理自然音景中语音的不同方面。一种对语音中存在的复杂听觉特征最为敏感，另一种对复杂听觉特征和快速时间调制最为敏感，这些特征并不局限于语音，另一种主要对声级进行编码。这些结果是在很少的先验假设下得出的，并提供了一个详细的、计算上可重复的关于颞叶皮层活动的描述，这些活动是由自然声景中的语音处理引起的。
Speech comprehension in natural soundscapes rests on the ability of the auditory system to extract speech information from a complex acoustic signal with overlapping contributions from many sound sources. Here we reveal the canonical processing of speech in natural soundscapes on multiple scales by using data-driven modeling approaches to characterize sounds to analyze ultra high field fMRI recorded while participants listened to the audio soundtrack of a movie. We show that at the functional level the neuronal processing of speech in natural soundscapes can be surprisingly low dimensional in the human cortex, highlighting the functional efficiency of the auditory system for a seemingly complex task. Particularly, we find that a model comprising three functional dimensions of auditory processing in the temporal lobes is shared across participants’ fMRI activity. We further demonstrate that the three functional dimensions are implemented in anatomically overlapping networks that process different aspects of speech in natural soundscapes. One is most sensitive to complex auditory features present in speech, another to complex auditory features and fast temporal modulations, that are not specific to speech, and one codes mainly sound level. These results were derived with few a-priori assumptions and provide a detailed and computationally reproducible account of the cortical activity in the temporal lobe elicited by the processing of speech in natural soundscapes.