Processing of complex sounds in the auditory cortex of cat, monkey, and man.
Processing of complex sounds in the auditory cortex of cat, monkey, and man.
复制标题
DOI：
10.3109/00016489709126142
复制
发表时间：
1997
期刊：
影响因子：
--
通讯作者：
J. Rauschecker
中科院分区：
文献类型：
--
作者：
J. Rauschecker
在视觉系统30年的研究中出现的感觉皮层组织的基本特征之一是感觉世界在大脑皮层中的多重表征。与视觉系统相比，中枢听觉系统中多个映射的功能特化信息较少。这是令人惊讶的，因为理解中央听觉表征似乎是理解更高的听觉处理所必需的，包括对语音的感知和对听觉空间的感知。我们记录了猫和恒河猴听觉皮层高级区域的单个神经元活动。在猫中，活动记录在前外侧（AE）皮质（AEA和AAF区）的尾部。超过一半的神经元在方位角和仰角上都能清楚地调谐到声源的位置。调频（FM）的声音引起最好的反应，在快速的调制。相比之下，后外侧裂（PE）区（PAF，VPAF）的神经元对慢FM率的反应更好。这表明AE皮层中空间属性处理的可能专门化，以及PE中听觉“模式”的可能偏好。在猕猴，我们探讨了问题的并行处理在更高的听觉通路结合病变和解剖示踪技术与单单位记录。初级听觉皮层（AI）的失活消除了尾内侧区（CM）的纯音反应，但在吻侧区（R）没有。逆行荧光示踪剂注射到R表现出强烈的标记的主要，腹侧核的内侧膝状体（MGv）。这两项研究结果表明，在听觉皮层中存在平行的通路，起源于更多的周边网站，并可能专门用于处理听觉空间与听觉模式。利用猕猴特有的交流声等复杂刺激进一步探讨了猕猴听觉皮层的听觉模式通路。侧带区（AL、ML和CL）的神经元对带通噪声刺激、一定速率和方向的FM声音以及某些类别的猴子叫声的反应非常有选择性。我们现在正在探索人类听觉皮层的更高区域，通过非侵入性功能磁共振成像（fMRI）测量皮层激活，同时刺激复杂的听觉声音。
One of the fundamental features in the organization of sensory cortices which has emerged from 30 years of research in the visual system is the existence of multiple representation of the sensory world in the cerebral cortex. Compared with the visual system much less information exists about the functional specialization of multiple maps in the central auditory system. This is surprising, since an understanding of central auditory representations seems necessary for an understanding of higher auditory processing, including the perception of speech and the perception of auditory space. We have recorded single neuron activity in higher areas of auditory cortex of cats and rhesus monkeys. In cats, activity was recorded in the caudal part of the anterior ectosylvian (AE) cortex (areas AEA and AAF). More than half of the neurons were clearly tuned to the location of a sound source in azimuth and elevation. Frequency-modulated (FM) sounds elicited best responses at fast rates of modulation. By contrast, neurons in the posterior ectosylvian (PE) areas (PAF, VPAF) responded better to slow FM rates. This suggests a possible specialization for the processing of spatial attributes in the AE cortex, and a possible preference for auditory "patterns" in PE. In macaque monkeys, we explored the question of parallel processing in the higher auditory pathways by combining lesion and anatomical tracer techniques with single unit recording. Inactivation of primary auditory cortex (AI) abolished pure-tone responses in the caudomedial area (CM), but not in the rostral area (R). Injections of retrograde fluorescent tracers into R showed strong labeling of the main, ventral nucleus of the medial geniculate (MGv). Both findings suggest the existence of parallel pathways in the auditory cortex, originating at more peripheral sites and possibly specialized for the processing of auditory space vs. auditory patterns. The auditory pattern pathway in Macaque auditory cortex was further explored by using complex stimuli including Macaque-specific communication sounds. Neurons in the lateral belt areas (AL, ML, and CL) respond very selectively to bandpassed noise stimuli, to FM sounds of a certain rate and direction, as well as to certain classes of monkey calls. We are now in the process of exploring higher areas of human auditory cortex by measuring cortical activation with noninvasive functional magnetic resonance imaging (fMRI) while stimulating with complex auditory sounds.