The optimality of sensory processing during the speed-accuracy tradeoff.
The optimality of sensory processing during the speed-accuracy tradeoff.
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DOI：
10.1523/jneurosci.0340-12.2012
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发表时间：
2012-06-06
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影响因子：
--
通讯作者：
Serences JT
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文献类型：
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作者：
Ho T;Brown S;van Maanen L;Forstmann BU;Wagenmakers EJ;Serences JT
当人们快速做出决定时，准确性就会受到影响。传统上，速度-准确性权衡（SAT）几乎完全归因于支持响应（响应谨慎）所需的感官证据量的变化以及与决策后期相关的神经相关性（例如，运动响应生成和执行）。在这里，我们研究了速度压力下的性能下降是否也反映了初级视觉皮层（V1）等早期感觉区域的次优信息处理。人类受试者进行了方向辨别任务，同时强调响应速度或准确性。一个选择行为模型显示，当受试者强调准确性而不是速度时，感官证据积累的速率被选择性地调制，这表明感官处理的变化也会影响SAT。然后，我们使用功能性磁共振成像（fMRI）和正向编码模型来推导方向选择性调谐功能的基础上激活模式V1。当强调准确性时，方向选择性调谐配置文件表现出理论上的最佳增益模式的程度预测响应的准确性和感官证据积累的速度。然而，当受试者强调速度时，没有观察到这些关系。总的来说，我们的研究结果表明，除了降低反应阈值，在快速决策过程中观察到的性能下降可能是由于未能最佳地处理感官信号。
When people make decisions quickly, accuracy suffers. Traditionally, speed-accuracy tradeoffs (SAT) have been almost exclusively ascribed to changes in the amount of sensory evidence required to support a response (response caution) and the neural correlates associated with the later stages of decision making (e.g., motor response generation and execution). Here, we investigated whether performance decrements under speed pressure also reflect suboptimal information processing in early sensory areas such as primary visual cortex (V1). Human subjects performed an orientation discrimination task while emphasizing either response speed or accuracy. A model of choice behavior revealed that the rate of sensory evidence accumulation was selectively modulated when subjects emphasized accuracy, but not speed, suggesting that changes in sensory processing also influence the SAT. We then used functional MRI (fMRI) and a forward encoding model to derive orientation-selective tuning functions based on activation patterns in V1. When accuracy was emphasized, the extent to which orientation-selective tuning profiles exhibited a theoretically optimal gain pattern predicted both response accuracy and the rate of sensory evidence accumulation. However, these relationships were not observed when subjects emphasized speed. Collectively, our findings suggest that, in addition to lowered response thresholds, the performance decrements observed during speeded decision making may result from a failure to optimally process sensory signals.