图 书 馆
go/nogo中的战略不耐烦与强迫选择决策Strategic Impatience in Go/NoGo versus Forced-Choice Decision-Making |
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| 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: |  |
| 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: | 选择行为; 漂移扩散模型; 贝叶斯风险 |
| 课程来源: | 视频讲座网 |
| 最后编审: | 2019-09-07：lxf |
| 阅读次数: | 118 |