Maturation of cortical mismatch responses to occasional pitch change in early infancy: Effects of presentation rate and magnitude of change
Maturation of cortical mismatch responses to occasional pitch change in early infancy: Effects of presentation rate and magnitude of change
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DOI：
10.1016/j.neuropsychologia.2008.07.019
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发表时间：
2009-01-01
期刊：
影响因子：
2.6
通讯作者：
Trainor, Laurel J.
中科院分区：
文献类型：
--
作者：
He, Chao;Hotson, Lisa;Trainor, Laurel J.
以往的研究报道了两种类型的事件相关电位（ERP）的不匹配反应，婴儿罕见的听觉变化：广泛的歧视性积极在年幼的婴儿和消极类似成人不匹配负（MMN）在老年婴儿。在本研究中，我们调查是否积极的歧视性慢波和成人样MMN功能不同，通过检查他们是如何受到影响的介绍率和变化幅度。我们测量了成年人、2个月大的婴儿和4个月大的婴儿的ERP，以重复钢琴音调（标准），偶尔改变音高（偏差）。标准和偏差之间的音高变化或小（1/12倍频程）或大（1/2倍频程）的幅度，和刺激呈现速率慢（800毫秒SOA）或快（400毫秒SOA）。随着呈现率的增加，成人和4个月大的婴儿都表现出MMN反应，潜伏期下降，但幅度不受影响。随着音高变化幅度的增加，MMN的振幅也增加。另一方面，仅在2个月大的婴儿中观察到广泛的正错配反应。随着呈现率的增加，2个月龄幼儿对标准音的反应幅度降低，而对异常音的反应幅度不受影响。音高变化的幅度并不影响2个月大的婴儿的反应。这些结果表明，音高是不同的处理在听觉皮层由2个月大和4个月大的孩子，和皮质变化检测机制音高歧视类似的成人出现在2至4个月的年龄。(C)2008爱思唯尔有限公司保留所有权利。
Previous studies have reported two types of event-related potential (ERP) mismatch responses in infants to infrequent auditory changes: a broad discriminative positivity in younger infants and a negativity resembling adult mismatch negativity (MMN) in older infants. In the present study, we investigated whether the positive discriminative slow wave and the adult-like MMN are functionally distinct by examining how they are affected by presentation rate and magnitude of change. We measured ERPs from adults, 2-month-olds, and 4-month-olds to a repeating piano tone (standard) that occasionally changed in pitch (deviant). The pitch changes between standards and deviants were either small (1/12 octave) or large (1/2 octave) in magnitude, and the stimulus presentation rate was either slow (800 ms SOA) or fast (400 ms SOA). As the presentation rate increased, both adults and 4-month-olds showed an MMN response that decreased in latency, but was unaffected in amplitude. As the magnitude of the pitch change increased, MMN increased in amplitude. On the other hand, only a broad positive mismatch response was seen in 2-month-olds. As the presentation rate increased, 2-month-olds' responses to standard tones decreased in amplitude while their responses to deviant tones were unaffected. The magnitude of the pitch change did not affect 2-month-olds' responses. These results suggest that pitch is processed differently in auditory cortex by 2-month-olds and 4-month-olds, and that a cortical change-detection mechanism for pitch discrimination similar to that of adults emerges between 2 and 4 months of age. (C) 2008 Elsevier Ltd. All rights reserved.