Successive-signal biasing for a learned sound sequence
Successive-signal biasing for a learned sound sequence
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DOI：
10.1073/pnas.1009433107
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发表时间：
2010-08
期刊：
影响因子：
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通讯作者：
Xiaoming Zhou;É. de Villers-Sidani;R. Panizzutti;M. Merzenich
中科院分区：
文献类型：
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作者：
Xiaoming Zhou;É. de Villers-Sidani;R. Panizzutti;M. Merzenich
成年大鼠被训练在其他九个非目标声音对的背景中检测二元声音序列的发生。训练导致了一个温和的，持久的，静态的扩大代表两个目标刺激声音的皮层区域。更重要的是，一旦目标A-B序列中的初始刺激A被呈现，皮层“地图”就会动态地改变，特别是进一步夸大“预期”刺激B的表征。如果发生了B，它在更大的皮层区域上表现为更强烈的兴奋，更协调，更有选择性的反应神经元。该偏倚在相对于A发作的B发作的预期时间达到峰值。没有动态偏置的响应记录的任何声音在一个非目标对。只有在B出现的预期时间出现A后，对B代表两侧的非目标频率的反应才会在面积和反应强度上减少。这项研究表明，大脑皮层区域并不是静态的，相反，它可以随着行为环境的变化而随时发生变化。
Adult rats were trained to detect the occurrence of a two-element sound sequence in a background of nine other nontarget sound pairs. Training resulted in a modest, enduring, static expansion of the cortical areas of representation of both target stimulus sounds. More importantly, once the initial stimulus A in the target A-B sequence was presented, the cortical “map” changed dynamically, specifically to exaggerate further the representation of the “anticipated” stimulus B. If B occurred, it was represented over a larger cortical area by more strongly excited, more coordinated, and more selectively responding neurons. This biasing peaked at the expected time of B onset with respect to A onset. No dynamic biasing of responses was recorded for any sound presented in a nontarget pair. Responses to nontarget frequencies flanking the representation of B were reduced in area and in response strength only after the presentation of A at the expected time of B onset. This study shows that cortical areas are not representationally static but, to the contrary, can be biased moment by moment in time as a function of behavioral context.