Human posterior auditory cortex gates novel sounds to consciousness
Human posterior auditory cortex gates novel sounds to consciousness
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DOI：
10.1073/pnas.0303760101
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发表时间：
2004-04-27
影响因子：
11.1
通讯作者：
Belliveau, JW
中科院分区：
文献类型：
--
作者：
Jääskeläinen, IP;Ahveninen, J;Belliveau, JW
在恶劣的环境中，生存或死亡关键取决于一个人检测和感知新声音的能力，比如在嘈杂的丛林中，一根树枝在一个跟踪捕食者的爪子下断裂的声音。两种不同的听觉皮层过程被认为是这种现象的基础：（i）重复刺激引起的所谓N1反应的衰减和（ii）听觉刺激重复方面的变化引起的失配负性反应（MMN）。这种划分是基于以前的研究表明，与N1不同，重复的“标准”刺激之前的物理上不同的“新”刺激构成的先决条件MMN引出，MMN和NI的源位点是不同的。与这些研究结果相矛盾，我们结合的电磁，血液动力学和心理物理学数据表明，MMN产生的前，后听觉皮层N1源的前听觉刺激的差异适应的结果。早期（约85 ms）后听觉皮层的神经活动随着声音新奇性的降低而适应。这改变了电磁N1源活动的重心，创建一个虚幻的差异N1和MMN源轨迹时，估计使用等效电流偶极子拟合。此外，我们的脑电图数据显示了一个强大的MMN后，一个标准的事件时，两个连续的新的声音之间的间隔保持不变。我们的研究结果表明，人类后听觉皮层内的特征特异性神经元的短暂适应过滤了多余的声音，使其无法进入人们的意识。
Life or death in hostile environments depends crucially on one's ability to detect and gate novel sounds to awareness, such as that of a twig cracking under the paw of a stalking predator in a noisy jungle. Two distinct auditory cortex processes have been thought to underlie this phenomenon: (i) attenuation of the so-called N1 response with repeated stimulation and (ii) elicitation of a mismatch negativity response (MMN) by changes in repetitive aspects of auditory stimulation. This division has been based on previous studies suggesting that, unlike for the N1, repetitive "standard" stimuli preceding a physically different "novel" stimulus constitute a prerequisite to MMN elicitation, and that the source loci of MMN and NI are different. Contradicting these findings, our combined electromagnetic, hemodynamic, and psychophysical data indicate that the MMN is generated as a result of differential adaptation of anterior and posterior auditory cortex N1 sources by preceding auditory stimulation. Early (approximate to85 ms) neural activity within posterior auditory cortex is adapted as sound novelty decreases. This alters the center of gravity of electromagnetic N1 source activity, creating an illusory difference between N1 and MMN source loci when estimated by using equivalent current dipole fits. Further, our electroencephalography data show a robust MMN after a single standard event when the interval between two consecutive novel sounds is kept invariant. Our converging findings suggest that transient adaptation of feature-specific neurons within human posterior auditory cortex filters superfluous sounds from entering one's awareness.