Rat performance on visual detection task modeled with divisive normalization and adaptive decision thresholds
Rat performance on visual detection task modeled with divisive normalization and adaptive decision thresholds
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DOI：
10.1167/11.9.1
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发表时间：
2011-01-01
影响因子：
1.8
通讯作者：
Reinagel, Pamela
中科院分区：
文献类型：
--
作者：
Meier, Philip;Reinagel, Pamela
任何知觉任务的表现都取决于受试者的知觉能力和决策策略。我们提供了一个模型，以适应这两个方面，并将其应用到执行检测任务的大鼠的数据。当老鼠必须检测到一个微弱的视觉目标时，附近其他刺激物（“侧翼”）的存在增加了任务的难度。在这项研究中，我们考虑了两个具体因素。首先，侧翼可以通过在早期视觉加工中的空间对比度归一化来减少对目标的感觉反应。第二，大鼠可能会把侧翼引起的感觉信号当作是属于目标的。我们称之为来源混淆，它可能是感官的，认知的，或两者兼而有之。我们通过将模型参数拟合到所观察到的行为数据的可能性来解释对比度归一化和源混淆。我们使用是/否检测任务测试目标和侧翼对比的多种组合。对比度正常化对于解释大鼠侧翼诱导的检测障碍至关重要。通过在对比度归一化框架中添加决策变量，我们的模型提供了一种新的工具来评估正常和异常啮齿动物之间视觉或认知脑功能的差异。
Performance on any perceptual task depends on both the perceptual capacity and the decision strategy of the subject. We provide a model to fit both aspects and apply it to data from rats performing a detection task. When rats must detect a faint visual target, the presence of other nearby stimuli ("flankers") increases the difficulty of the task. In this study, we consider two specific factors. First, flankers could diminish the sensory response to the target via spatial contrast normalization in early visual processing. Second, rats may treat the sensory signal caused by the flankers as if it belonged to the target. We call this source confusion, which may be sensory, cognitive, or both. We account for contrast normalization and source confusion by fitting model parameters to the likelihood of the observed behavioral data. We test multiple combinations of target and flanker contrasts using a yes/no detection task. Contrast normalization was crucial to explain the rats' flanker-induced detection impairment. By adding a decision variable to the contrast normalization framework, our model provides a new tool to assess differences in visual or cognitive brain function between normal and abnormal rodents.