Adverse Listening Conditions and Memory Load Drive a Common Alpha Oscillatory Network
Adverse Listening Conditions and Memory Load Drive a Common Alpha Oscillatory Network
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DOI：
10.1523/jneurosci.4908-11.2012
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发表时间：
2012-09-05
影响因子：
5.3
通讯作者：
Maess, Burkhard
中科院分区：
文献类型：
--
作者：
Obleser, Jonas;Woestmann, Malte;Maess, Burkhard
听觉退化如何影响工作记忆的神经机制？在工作记忆中保留项目期间增强的α振荡（8-13 Hz）通常被解释为反映对存储和抑制的需求增加。我们假设，听觉信号退化对人类听众构成了额外的挑战，部分原因是它利用了相同的神经机制。在一个适应的斯滕贝格范式，听觉记忆负荷和声学退化的参数变化和脑磁图反应进行了分析，在时间-频率域。值得注意的是，在无刺激延迟间期期间，中央-顶叶传感器处的α功率作为记忆负荷（具有更多记忆负荷的更高α功率）和声学退化（也具有更严重的声学退化的更高α功率）的函数单调增加。当最高负荷与最严重的降解相结合时，这种α效应是超加性的。此外，在无刺激延迟的α振荡动力学预测的响应时间的探测项目。无刺激延迟期间α功率的源定位表明，右侧顶叶、扣带回、边缘上和上级颞叶皮层的α发生器对组合记忆负荷和声学退化敏感。总之，存储器负载和声学退化的挑战都增加了常见α频率网络中的活动。这些结果为未来关于感觉输入的慢性或急性退化如何影响执行控制机制的研究奠定了基础。
How does acoustic degradation affect the neural mechanisms of working memory? Enhanced alpha oscillations (8-13 Hz) during retention of items in working memory are often interpreted to reflect increased demands on storage and inhibition. We hypothesized that auditory signal degradation poses an additional challenge to human listeners partly because it draws on the same neural mechanisms. In an adapted Sternberg paradigm, auditory memory load and acoustic degradation were parametrically varied and the magnetoencephalographic response was analyzed in the time-frequency domain. Notably, during the stimulus-free delay interval, alpha power monotonically increased at central-parietal sensors as functions of memory load (higher alpha power with more memory load) and of acoustic degradation (also higher alpha power with more severe acoustic degradation). This alpha effect was superadditive when highest load was combined with most severe degradation. Moreover, alpha oscillatory dynamics during stimulus-free delay were predictive of response times to the probe item. Source localization of alpha power during stimulus-free delay indicated that alpha generators in right parietal, cingulate, supramarginal, and superior temporal cortex were sensitive to combined memory load and acoustic degradation. In summary, both challenges of memory load and acoustic degradation increase activity in a common alpha-frequency network. The results set the stage for future studies on how chronic or acute degradations of sensory input affect mechanisms of executive control.