The context of uncertainty modulates the subcortical response to predictability
The context of uncertainty modulates the subcortical response to predictability
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DOI：
10.1162/089892901753165881
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发表时间：
2001-10-01
影响因子：
3.2
通讯作者：
Berns, GS
中科院分区：
文献类型：
--
作者：
Bischoff-Grethe, A;Martin, M;Berns, GS
内隐运动学习任务通常涉及比较序列和随机条件下受试者的反应。在神经影像学中，描述了与序列相关的大脑区域，但通常没有探索序列与非序列条件的时间关系。我们提出了一项功能磁共振成像（fMRI）研究，描述了与隐式感觉运动学习任务中的顺序可预测性相关的激活以及这些效应的历史（上下文）依赖性。参与者观察屏幕上水平显示的四个方块，并在四个目标中的任何一个以特定颜色照亮时按下按钮。具有不同可预测性水平的重复空间序列嵌入在随机颜色呈现中。右侧背外侧前额叶皮层（R DLPFC）和右侧尾状核均与可预测性的增加呈正相关，而左侧后顶叶皮层（L PPC）则呈负相关。然而，当从高可预测性转变为低可预测性时，尾状核内的激活变化显着，但在相反的情况下则不然，这表明不仅对可预测性而且对顺序效应也敏感。这些结果支持基底神经节和视觉运动顺序学习之间的假设关系，但证明了上下文对顺序学习的重要性。
Implicit motor learning tasks typically involve comparisons of subject responses during a sequence versus a random condition. In neuroimaging, brain regions that are correlated with a sequence are described, but the temporal relationship of sequence versus nonsequence conditions is often not explored. We present a functional magnetic resonance imaging (fMRI) study describing activation related to sequential predictability in an implicit sensorimotor learning task and the history (context) dependence of these effects. Participants regarded four squares displayed horizontally across a screen and pressed a button when any one of the four targets was illuminated in a particular color. A repeating spatial sequence with varying levels of predictability was embedded within a random color presentation. Both the right dorsolateral prefrontal cortex (R DLPFC) and right caudate displayed a positive correlation to increasing predictability, whereas the left posterior parietal cortex (L PPC) displayed a negative correlation. However, the activation changes within the caudate were significant when transitioning from high predictability to low predictability but not for the reverse case, suggesting a sensitivity not only to predictability but to order effects as well. These results support the hypothesized relationship between basal ganglia and visuomotor sequential learning, but demonstrate the importance of context upon sequence learning.