Interhemispheric Differences in Auditory Processing Revealed by fMRI in Awake Rhesus Monkeys
Interhemispheric Differences in Auditory Processing Revealed by fMRI in Awake Rhesus Monkeys
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DOI：
10.1093/cercor/bhr150
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发表时间：
2012-04-01
期刊：
影响因子：
3.7
通讯作者：
Orban, Guy A.
中科院分区：
文献类型：
--
作者：
Joly, Olivier;Ramus, Franck;Orban, Guy A.
对猴子的损伤研究表明，左半球在处理物种特异性发声方面具有适度的优势，其神经基础迄今仍不清楚。我们使用造影剂增强功能磁共振成像来绘制恒河猴大脑中参与处理同种发声以及人类语音和情感声音的区域。控制条件包括所有3种刺激的加扰版本和沉默。与沉默相比，所有刺激都激活了听觉皮层和皮层下听觉结构的广泛部分，在听觉核心水平上具有右半球偏向。然而，将完整的声音与杂乱的声音进行比较，发现听觉带和parabelt中存在一种偏误。左侧优势是更强大，更强大的人类语音比恒河猴发声，因此并不反映同种呼叫选择性，而是复杂的spectrotemporal模式，如那些存在于人类语音和一些恒河猴发声的处理。这一点通过回归大脑活动与模型衍生的参数索引的流行，这种模式得到了证实。我们的研究结果表明，在侧带和parabelt的声音处理是不对称的猴子，从病变的研究预测。
Lesion studies in monkeys have suggested a modest left hemisphere dominance for processing species-specific vocalizations, the neural basis of which has thus far remained unclear. We used contrast agent-enhanced functional magnetic resonance imaging to map the regions of the rhesus monkey brain involved in processing conspecific vocalizations as well as human speech and emotional sounds. Control conditions included scrambled versions of all 3 stimuli and silence. Compared with silence, all stimuli activated widespread parts of the auditory cortex and subcortical auditory structures with a right hemispheric bias at the level of the auditory core. However, comparing intact with scrambled sounds revealed a leftward bias in the auditory belt and the parabelt. The left-sided dominance was stronger and more robust for human speech than for rhesus vocalizations and hence does not reflect conspecific call selectivity but rather the processing of complex spectrotemporal patterns, such as those present in human speech and in some of the rhesus monkey vocalizations. This was confirmed by regressing brain activity with a model-derived parameter indexing the prevalence of such patterns. Our results indicate that processing of vocal sounds in the lateral belt and parabelt is asymmetric in monkeys, as predicted from lesion studies.