Mismatch negativity (MMN) reveals inefficient auditory ventral stream function in chronic auditory comprehension impairments.
Mismatch negativity (MMN) reveals inefficient auditory ventral stream function in chronic auditory comprehension impairments.
复制标题
失配负性（MMN）揭示了慢性听觉理解障碍中听觉腹侧流功能的低效。
DOI：
10.1016/j.cortex.2014.07.009
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Robson H
中科院分区：
文献类型：
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作者：
Robson H
研究背景韦尼克失语症（Wernicke 'saphasia，WA）患者的听觉辨别能力明显受损，并被认为与语言理解障碍有关。本研究采用错配负波（MMN）技术，探讨WA患者听觉辨别成功和受损时的神经反应。方法测量WA（n= 7）和对照组（n= 7）的辅音-元音-辅音（CVC）音节和纯音（PT）的行为听觉辨别阈值。阈值的结果被用来开发多个越轨MMN古怪的范式包含越轨行为，这是可感知的或不可感知的标准刺激不同。MMN分析研究与组，条件和感知的差异，以及MMN的反应和理解之间的关系（其中行为的听觉歧视配置文件进行了检查）。ResultsMMN波形可观察到的感知和不可感知的听觉变化。在PT条件下，感知性仅通过MMN振幅来区分。WA组与对照组的区别在于对CVC刺激变化的MMN反应潜伏期增加。相关性分析显示行为CVC歧视和MMN振幅之间的关系，在对照组中，更大的振幅对应于更好的歧视。WA组表现出相反的效果，无论是歧视的准确性和听觉理解分数降低MMN振幅增加。在WA组中，观察到MMN反应的偏侧化与CVC辨别准确性之间存在进一步的相关性;结论本研究的结果为WA患者听觉理解障碍的性质提供了进一步的证据，并表明听觉辨别缺陷是基于参与有效层次加工的能力降低，不变听觉对象的构造。相关结果表明，慢性WA的人可能依赖于一个效率低下，嘈杂的右半球听觉流时，试图处理语音刺激。
BackgroundAuditory discrimination is significantly impaired in Wernicke's aphasia (WA) and thought to be causatively related to the language comprehension impairment which characterises the condition. This study used mismatch negativity (MMN) to investigate the neural responses corresponding to successful and impaired auditory discrimination in WA.MethodsBehavioural auditory discrimination thresholds of consonant-vowel-consonant (CVC) syllables and pure tones (PTs) were measured in WA (n= 7) and control (n= 7) participants. Threshold results were used to develop multiple deviant MMN oddball paradigms containing deviants which were either perceptibly or non-perceptibly different from the standard stimuli. MMN analysis investigated differences associated with group, condition and perceptibility as well as the relationship between MMN responses and comprehension (within which behavioural auditory discrimination profiles were examined).ResultsMMN waveforms were observable to both perceptible and non-perceptible auditory changes. Perceptibility was only distinguished by MMN amplitude in the PT condition. The WA group could be distinguished from controls by an increase in MMN response latency to CVC stimuli change. Correlation analyses displayed a relationship between behavioural CVC discrimination and MMN amplitude in the control group, where greater amplitude corresponded to better discrimination. The WA group displayed the inverse effect; both discrimination accuracy and auditory comprehension scores were reduced with increased MMN amplitude. In the WA group, a further correlation was observed between the lateralisation of MMN response and CVC discrimination accuracy; the greater the bilateral involvement the better the discrimination accuracy.ConclusionsThe results from this study provide further evidence for the nature of auditory comprehension impairment in WA and indicate that the auditory discrimination deficit is grounded in a reduced ability to engage in efficient hierarchical processing and the construction of invariant auditory objects. Correlation results suggest that people with chronic WA may rely on an inefficient, noisy right hemisphere auditory stream when attempting to process speech stimuli.