Decisions in Changing Conditions: The Urgency-Gating Model
Decisions in Changing Conditions: The Urgency-Gating Model
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DOI：
10.1523/jneurosci.1844-09.2009
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发表时间：
2009-09-16
影响因子：
5.3
通讯作者：
El-Murr, Stephany
中科院分区：
文献类型：
--
作者：
Cisek, Paul;Puskas, Genevieve Aude;El-Murr, Stephany
几个被广泛接受的决策模型表明，在简单的决策任务中，神经活动会不断积累，直到达到一个阈值，然后做出决策。这些模型解释了各种任务中的错误率和反应时间分布，并得到神经生理学研究的支持，这些研究表明，几个皮层和皮层下区域的神经活动以与任务难度相关的速率逐渐建立，并在预测运动开始的时间内达到相对恒定的放电水平。这种积累的机制被认为与连续的感觉信息样本的时间整合有关。然而，另一种可能解释神经和行为数据的机制是，活动的积累可归因于与反应紧迫性相关的日益增长的信号，这种信号成倍地调节了对感官证据的更新估计。这些模型很难区分，因为在以前的研究中，受试者在每次试验中都有持续的感官证据。为了区分这些模型，我们向人类受试者提供了一项任务，其中的证据在每次试验过程中都会发生变化。我们的结果更符合“紧急门控”而不是感官样本的时间整合，并提出了一种简单的机制来实现决策速度和准确性之间的权衡。
Several widely accepted models of decision making suggest that, during simple decision tasks, neural activity builds up until a threshold is reached and a decision is made. These models explain error rates and reaction time distributions in a variety of tasks and are supported by neurophysiological studies showing that neural activity in several cortical and subcortical regions gradually builds up at a rate related to task difficulty and reaches a relatively constant level of discharge at a time that predicts movement initiation. The mechanism responsible for this buildup is believed to be related to the temporal integration of sequential samples of sensory information. However, an alternative mechanism that may explain the neural and behavioral data is one in which the buildup of activity is instead attributable to a growing signal related to the urgency to respond, which multiplicatively modulates updated estimates of sensory evidence. These models are difficult to distinguish when, as in previous studies, subjects are presented with constant sensory evidence throughout each trial. To distinguish the models, we presented human subjects with a task in which evidence changed over the course of each trial. Our results are more consistent with "urgency gating" than with temporal integration of sensory samples and suggest a simple mechanism for implementing trade-offs between the speed and accuracy of decisions.