Neural Correlates of Decision Thresholds in the Human Subthalamic Nucleus.
Neural Correlates of Decision Thresholds in the Human Subthalamic Nucleus.
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DOI：
10.1016/j.cub.2016.01.051
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发表时间：
2016-04-04
期刊：
影响因子：
--
通讯作者：
Brown P
中科院分区：
文献类型：
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作者：
Herz DM;Zavala BA;Bogacz R;Brown P
如果人类在做决定时面临困难的选择，为了避免次优选择，放慢反应的能力变得至关重要。目前的决策模型假设，丘脑底核（subthalamic nucleus，简称Nucleus）通过提高决策阈值来介导这一功能，因此在做出反应之前需要积累更多的证据。然而，直接的电生理学证据的确切作用，在调整决策阈值是缺乏的。在这里，我们表明，一次又一次的试验变化在低频振荡活动预测调整的决策阈值之前，受试者作出反应。决策阈值和活动性之间的关系主要取决于受试者的谨慎程度。虽然增加的振荡活动的大脑皮层预测在高水平的谨慎提高决策阈值，它预测在低水平的谨慎降低决策阈值。这种上下文依赖的关系可能是介导的内侧前额叶皮层（mPFC）-ESTA通路的决策阈值在高谨慎的影响增加。受试者在做出反应之前表现出更强的mPFC和mPFC低频振荡活动相位对准增加，具有更高的决策阈值，并且错误反应较少。总之，我们的研究结果表明，低频率振荡活动和相应的mPFC的耦合参与确定有多少证据主体积累之前作出决定。这一发现可能解释了为什么大脑深部的刺激会削弱受试者减缓反应的能力，并可能导致冲动的次优决定。当综合证据越过"决策阈值"时，受试者做出选择。这种阈值通过丘脑底核中2 - 8-Hz的振荡来反映。决策阈值和神经活动之间的关系是依赖于上下文的。表明人类的决策阈值是由底丘脑低频振荡活动调节的。这种关系取决于受试者的谨慎程度，当需要谨慎时，内侧前额叶皮层-底丘脑通路对决策阈值的影响增加。
If humans are faced with difficult choices when making decisions, the ability to slow down responses becomes critical in order to avoid suboptimal choices. Current models of decision making assume that the subthalamic nucleus (STN) mediates this function by elevating decision thresholds, thereby requiring more evidence to be accumulated before responding. However, direct electrophysiological evidence for the exact role of STN during adjustment of decision thresholds is lacking. Here, we show that trial-by-trial variations in STN low-frequency oscillatory activity predict adjustments of decision thresholds before subjects make a response. The relationship between STN activity and decision thresholds critically depends on the subjects’ level of cautiousness. While increased oscillatory activity of the STN predicts elevated decision thresholds during high levels of cautiousness, it predicts decreased decision thresholds during low levels of cautiousness. This context-dependent relationship may be mediated by increased influence of the medial prefrontal cortex (mPFC)-STN pathway on decision thresholds during high cautiousness. Subjects who exhibit a stronger increase in phase alignment of low-frequency oscillatory activity in mPFC and STN before making a response have higher decision thresholds and commit fewer erroneous responses. Together, our results demonstrate that STN low-frequency oscillatory activity and corresponding mPFC-STN coupling are involved in determining how much evidence subjects accumulate before making a decision. This finding might explain why deep-brain stimulation of the STN can impair subjects’ ability to slow down responses and can induce impulsive suboptimal decisions. Subjects make a choice when the integrated evidence crosses a “decision threshold” Such thresholds are reflected by 2- to 8-Hz oscillations in the subthalamic nucleus The relationship between decision thresholds and STN activity is context dependent This is mediated by altered prefrontal-STN coupling during high cautiousness In this article, Herz et al. show that decision thresholds in humans are modulated by subthalamic low-frequency oscillatory activity. This relationship depends on the subjects’ level of cautiousness, which is mediated by increased influence of the medial prefrontal cortex-subthalamic pathway on decision thresholds when caution is required.