The neural mechanisms of perceptual decision making
The neural mechanisms of perceptual decision making
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知觉决策的神经机制
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发表时间：
2012
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通讯作者：
Tiffany Ho
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作者：
Tiffany Ho
感知决策（PDM）是指在感官证据的基础上从多个选项中选择一个选项，是生物体成功与环境相互作用的高度适应机制。这种选择需要整合和解释感官信息，以指导随后的行为（例如，看到一个球移动，并相应地转向去接住它）。典型的检查PDM的单单位记录研究利用简单的感觉运动任务（例如，猕猴观察在两个可能的方向之一上移动的点的噪声阵列，并且在所选择的（并且可能是感知到的）方向上展开扫视），以便解析PDM的各个方面。借助数学模型，这些实验发现，参与运动反应生成的单个神经元的活动包括感知决策，并且PDM可以被形式化为朝向特定选择的感觉证据的积累（如由神经元放电率的增加所表示的），直到达到某个阈值。然而，在神经群体水平上解释PDM的机制以及将神经活动的整体模式与感知联系起来仍然不清楚。结合视觉心理物理学，神经成像和建模，我提出了一组研究，探讨神经相关subserving PDM在人类皮层（实验1），澄清之间的关系在视觉皮层的感觉表征和感知性能（实验2），并测试来自单细胞记录的行为预测（实验3）。这些发现既挑战又证实了以前的一些神经生理学工作：实验1证明了PDM的神经机制并不完全基于眼区，实验2表明视皮层激活模式的最优性预测了任务绩效，实验3表明，注意操纵影响知觉的方式与不同的神经种群的增强和抑制一致从单一单位的记录预测。此外，这些研究还证明了基于模型的认知神经科学在量化每个人感兴趣的心理过程以及将受试者之间的差异与相应的大脑测量相关联方面的实用性
Perceptual decision making (PDM) involves choosing one option among several on the basis of sensory evidence and is a highly adaptive mechanism for organisms to successfully interact with their environments. Such a choice requires integrating and interpreting sensory information for the purpose of guiding subsequent behavior (e.g., seeing a ball move rightward and veering accordingly to catch it). Typical single-unit recording studies examining PDM utilize simple sensorimotor tasks (e.g., a macaque views a noisy array of dots moving in one of two possible directions and deploys a saccade in the chosen - and presumably, perceived - direction) in order to parse various aspects of PDM. With the aid of mathematical models, these experiments have found that the activity of individual neurons involved in motor response generation comprises perceptual decisions, and that PDM can be formalized as an accumulation of sensory evidence towards a particular choice (as represented by an increase in neuronal firing rate) until some threshold is reached. Explaining the mechanisms of PDM at the level of neural populations and linking ensemble patterns of neural activity to perception, however, still remains unclear. With a combination of visual psychophysics, neuroimaging, and modeling, I present a set of studies that examines the neural correlates subserving PDM in human cortex (Experiment 1), clarifies the relationship between sensory representations in visual cortex and perceptual performance (Experiment 2), and tests the behavioral predictions derived from single-cell recordings (Experiment 3). These findings both challenge and confirm some of the previous neurophysiological work: Experiment 1 provides evidence of a neural mechanism of PDM not based purely on oculomotor regions, Experiment 2 shows that the optimality of activation patterns in visual cortex predicts task performance, and Experiment 3 illustrates that attentional manipulations influence perception in a manner consistent with the enhancement and suppression of distinct neural populations predicted from single-unit recordings. Furthermore, these studies demonstrate the utility of model-based cognitive neuroscience in quantifying psychological processes of interest for each individual and relating between-subject differences with corresponding brain measurements