Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, UK.
Cereb Cortex. 2013 Sep;23(9):2025-37. doi: 10.1093/cercor/bhs162. Epub 2012 Jul 16.
The human brain is thought to process auditory objects along a hierarchical temporal "what" stream that progressively abstracts object information from the low-level structure (e.g., loudness) as processing proceeds along the middle-to-anterior direction. Empirical demonstrations of abstract object encoding, independent of low-level structure, have relied on speech stimuli, and non-speech studies of object-category encoding (e.g., human vocalizations) often lack a systematic assessment of low-level information (e.g., vocalizations are highly harmonic). It is currently unknown whether abstract encoding constitutes a general functional principle that operates for auditory objects other than speech. We combined multivariate analyses of functional imaging data with an accurate analysis of the low-level acoustical information to examine the abstract encoding of non-speech categories. We observed abstract encoding of the living and human-action sound categories in the fine-grained spatial distribution of activity in the middle-to-posterior temporal cortex (e.g., planum temporale). Abstract encoding of auditory objects appears to extend to non-speech biological sounds and to operate in regions other than the anterior temporal lobe. Neural processes for the abstract encoding of auditory objects might have facilitated the emergence of speech categories in our ancestors.
人类大脑被认为沿着一个分层的时间“什么”流来处理听觉对象，该流沿着从中到前的方向逐步从低水平结构（例如，响度）抽象出对象信息。独立于低水平结构的抽象对象编码的实证证明依赖于语音刺激，而对物体类别编码的非语音研究（例如，人类的发声）往往缺乏对低水平信息的系统评估（例如，发声具有高度的谐波性）。目前尚不清楚抽象编码是否构成了一种普遍的功能原则，适用于除语音之外的听觉对象。我们结合功能成像数据的多元分析和对低水平声学信息的精确分析，研究了非语音类别的抽象编码。我们观察到，在从中到后颞叶皮质的活动精细空间分布中，存在对生物声和人类动作声类别的抽象编码（例如颞平面）。听觉对象的抽象编码似乎扩展到了非语音生物声音，并在除前颞叶之外的区域起作用。听觉对象的抽象编码的神经过程可能促进了我们祖先的语音类别出现。
