Sound recognition and localization in man: specialized cortical networks and effects of acute circumscribed lesions
Sound recognition and localization in man: specialized cortical networks and effects of acute circumscribed lesions
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DOI：
10.1007/s00221-003-1616-0
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发表时间：
2003-12-01
影响因子：
2
通讯作者：
Clarke, S
中科院分区：
文献类型：
--
作者：
Adriani, M;Maeder, P;Clarke, S
功能成像研究表明，与声音识别和声音定位相关的信息是在解剖学上不同的皮层网络中处理的。我们研究了这些专门的网络的功能组织通过评估急性影响局限的半球病变。30例原发性单侧半球病变患者，15例右半球损伤（RHD）和15例左半球损伤（LHD），评估了他们识别环境声音、定位空间声音和感知声音运动的能力。1例RHD患者和2例LHD患者在声音识别方面存在选择性缺陷；RHD患者有声音定位的选择性缺陷；LHD患者有声音运动感知的选择性缺陷；4名RHD患者和3名LHD患者声音定位和运动感知的综合缺陷；2名RHD患者和1名LHD患者声音识别和运动感知的综合缺陷；1名LHD患者在声音识别、定位和运动感知方面存在综合缺陷。5例RHD患者和6例LHD患者在所有三个领域的表现均正常。声音识别、声音定位和/或声音运动感知方面的缺陷总是与涉及共同听觉结构和专门的What和/或Where网络的病变有关，而正常的表现则与这些区域内外的病变有关。因此，对正常受试者中参与听觉处理的区域的损伤是必要的，但不足以导致缺陷的发生。特殊神经网络的损害并不总是与相应的缺陷相关。相反，特异性缺陷往往不主要与相应网络的病变相关；例如，病变涉及共享听觉结构和专业What网络的程度大于涉及专业Where网络的患者，在听觉空间任务方面存在缺陷；病变主要涉及共享听觉结构和不同程度的专业What网络的患者，在声音识别方面存在缺陷。人类听觉皮层由功能明确的听觉区域组成，其内在组织目前尚不清楚。特别是，与What和Where通路相关的区域可以被认为：(1)专门的区域，其中病变导致的功能障碍仅限于受损部分；观察到的缺陷应与受损区域的专门化及其与损害程度的大小有关；或者(2)专门的网络，其中病变引起的功能障碍可能会蔓延到两个专门的网络；观察到的缺陷可能与受损区域无关，其大小与损伤程度不成比例。我们的研究结果有力地支持了网络假说。
Functional imaging studies have shown that information relevant to sound recognition and sound localization are processed in anatomically distinct cortical networks. We have investigated the functional organization of these specialized networks by evaluating acute effects of circumscribed hemispheric lesions. Thirty patients with a primary unilateral hemispheric lesion, 15 with right-hemispheric damage (RHD) and 15 with left-hemispheric damage (LHD), were evaluated for their capacity to recognise environmental sounds, to localize sounds in space and to perceive sound motion. One patient with RHD and 2 with LHD had a selective deficit in sound recognition; 3 with RHD a selective deficit in sound localization; 2 with LHD a selective deficit in sound motion perception; 4 with RHD and 3 with LHD a combined deficit of sound localization and motion perception; 2 with RHD and 1 with LHD a combined deficit of sound recognition and motion perception; and 1 with LHD a combined deficit of sound recognition, localization and motion perception. Five patients with RHD and 6 with LHD had normal performance in all three domains. Deficient performance in sound recognition, sound localization and/or sound motion perception was always associated with a lesion that involved the shared auditory structures and the specialized What and/or Where networks, while normal performance was associated with lesions within or outside these territories. Thus, damage to regions known to be involved in auditory processing in normal subjects is necessary, but not sufficient for a deficit to occur. Lesions of a specialized network was not always associated with the corresponding deficit. Conversely, specific deficits tended not be associated predominantly with lesions of the corresponding network; e.g. deficits in auditory spatial tasks were observed in patients whose lesions involved to a larger extent the shared auditory structures and the specialized What network than the specialized Where network, and deficits in sound recognition in patients whose lesions involved mostly the shared auditory structures and to a varying degree the specialized What network. The human auditory cortex consists of functionally defined auditory areas, whose intrinsic organization is currently not understood. In particular, areas involved in the What and Where pathways can be conceived as: (1) specialized regions, in which lesions cause dysfunction limited to the damaged part; observed deficits should be then related to the specialization of the damaged region and their magnitude to the extent of the damage; or (2) specialized networks, in which lesions cause dysfunction that may spread over the two specialized networks; observed deficits may then not be related to the damaged region and their magnitude not proportional to the extent of the damage. Our results support strongly the network hypothesis.