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去/不去与强迫选择决策中的战略不耐烦

Strategic Impatience in Go/NoGo versus Forced-Choice Decision-Making
课程网址: http://videolectures.net/nips2012_yu_decision/  
主讲教师: Angela J. Yu
开课单位: 加州大学圣地亚哥分校
开课时间: 2013-01-16
课程语种: 英语
中文简介:
两种替代强迫选择(2AFC)和Go/NoGo(GNG)任务是研究选择行为中感官和认知加工的行为选择范式。虽然GNG被认为是通过消除反应选择的需要来隔离感觉/决策成分,但GNG任务中对Go反应的一致偏见(较高的点击率和误报率)表明,这两项任务中涉及的感觉或认知过程可能存在根本性差异。这些选择任务的现有机制模型,主要是漂移扩散模型(DDM;[1,2])和相关的泄漏竞争累加器模型[3,4]的变体,捕捉了行为的各个方面,但没有解决Go偏差的来源。我们假设,这种“不耐烦”的围棋是一种战略调整,以应对GNG成本结构中隐含的不对称性:围棋的回应要求等到回应的最后期限,而围棋的回应立即终止当前的试验。我们证明了一个最小化错误率和平均决策延迟的贝叶斯风险最小化决策策略自然地表现出实验观察到的偏差。最优决策策略在形式上相当于一个具有时变阈值的DDM,该阈值在刺激开始后最初上升,在响应截止日期附近再次崩溃。最初的上升是由于选择Go响应而不是固定延迟NoGo响应的时间优势逐渐减弱。我们表明,将一个更简单、固定阈值的DDM拟合到最优模型中,会重现GNG中比2AFC决策更高阈值的违反直觉的结果,之前在直接DDM拟合行为数据[2]中观察到了这一点,尽管这种近似无法重现Go偏差。因此,观察到的GNG和2AFC决策之间的差异可能源于对成本结构的合理战略调整,并不一定意味着潜在感官和认知过程中的额外差异。
课程简介: Two-alternative forced choice (2AFC) and Go/NoGo (GNG) tasks are behavioral choice paradigms commonly used to study sensory and cognitive processing in choice behavior. While GNG is thought to isolate the sensory/decisional component by removing the need for response selection, a consistent bias towards the Go response (higher hits and false alarm rates) in the GNG task suggests possible fundamental differences in the sensory or cognitive processes engaged in the two tasks. Existing mechanistic models of these choice tasks, mostly variants of the drift-diffusion model (DDM; [1,2]) and the related leaky competing accumulator models [3,4] capture various aspects of behavior but do not address the provenance of the Go bias. We postulate that this ``impatience'' to go is a strategic adjustment in response to the implicit asymmetry in the cost structure of GNG: the NoGo response requires waiting until the response deadline, while a Go response immediately terminates the current trial. We show that a Bayes-risk minimizing decision policy that minimizes both error rate and average decision delay naturally exhibits the experimentally observed bias. The optimal decision policy is formally equivalent to a DDM with a time-varying threshold that initially rises after stimulus onset, and collapses again near the response deadline. The initial rise is due to the fading temporal advantage of choosing the Go response over the fixed-delay NoGo response. We show that fitting a simpler, fixed-threshold DDM to the optimal model reproduces the counterintuitive result of a higher threshold in GNG than 2AFC decision-making, previously observed in direct DDM fit to behavioral data [2], although such approximations cannot reproduce the Go bias. Thus, observed discrepancies between GNG and 2AFC decision-making may arise from rational strategic adjustments to the cost structure, and need not imply additional differences in the underlying sensory and cognitive processes.
关 键 词: 漂移扩散模型; 潜在感官和认知过程; 强迫选择
课程来源: 视频讲座网
数据采集: 2022-03-26:zkj
最后编审: 2022-03-26:zkj
阅读次数: 48