Lasso回归：从解释到预测

传统的最小二乘回归法关注于对当前数据集的准确估计, 容易导致模型的过拟合, 影响模型结论的可重复性。随着方法学领域的发展, 涌现出的新兴统计工具可以弥补传统方法的局限, 从过度关注回归系数值的解释转向提升研究结果的预测能力也愈加成为心理学领域重要的发展趋势。Lasso方法通过在模型估计中引入惩罚项的方式, 可以获得更高的预测准确度和模型概化能力, 同时也可以有效地处理过拟合和多重共线性问题, 有助于心理学理论的构建和完善。     

Postdecision consolidation in a trend prediction task

To be able to learn from experience it is necessary to correctly apprehend experienced feedback and the situation in which it is provided. The results indicate how post-decision consolidation in complex domains may affect learning. The problem may be particularly pertinent in recurrent decision making where considerable risk is involved. The study explores the changes in aspect (signal) importance from pre- to postdiction as a function of outcome information. By postdiction we mean the remembering of an earlier prediction (cf. Hawkins & Hastie, 1990). Subjects were asked to decide on which of four alternative future price developments would follow a historical price trajectory for different commodities, and to rate the importance of each of the chosen alternative's corresponding aspects. The subjects revealed a bias in their support ratings of aspects--seeing support in aspects that traditionally (by themselves and in many contexts) would be seen as neutral or even counter-indicative of the alternative chosen. After an intermission, the subjects were also given information about what was indicated to be the actual development of the market. One group was told that their decisions were correct (irrespective of what the decisions were), another group that they were incorrect but close, a third group that they were incorrect by far, while a fourth group served as a control. Following this information the subjects were again asked to judge the importance of the aspects for their own prior decision on the most likely future development. The results indicated that outcome feed-back had an effect on post decision restructuring of facts. Subjects in the correct condition showed an average consolidation that increased the support, while the wrong conditions lead to negative consolidation (in retrospect indicating that they never found as much support for their decision in the past as they actually did). Thus, in a choice between consolidating their own initial prediction and the price trajectory they would have to live with, the decision makers consolidated the outcome. Therefore, the results of the study were related to the hindsight bias phenomenon (Fischhoff, 1975) and to Kahneman and Miller's (1986) mutability concept.     

Predicting elections from the most important issue: A test of the take‐the‐best heuristic

We used the take‐the‐best heuristic to develop a model to forecast the popular two‐party vote shares in U.S. presidential elections. The model draws upon information about how voters expect the candidates to deal with the most important issue facing the country. We used cross‐validation to calculate a total of 1000 out‐of‐sample forecasts, one for each of the last 100 days of the ten U.S. presidential elections from 1972 to 2008. Ninety‐seven per cent of forecasts correctly predicted the winner of the popular vote. The model forecasts were competitive compared to forecasts from methods that incorporate substantially more information (e.g., econometric models and the Iowa Electronic Markets). The purpose of the model is to provide fast advice on which issues candidates should stress in their campaign. Copyright © 2010 John Wiley & Sons, Ltd.     

Hindsight Bias Demonstrated in the Prediction of a Sporting Event

Abstract

The authors examined hindsight bias in the context of a sporting event (Super Bowl XXXIII) with individuals who had previous knowledge of the hindsight bias–42 students who were currently enrolled in psychology classes that had previously covered hindsight bias. To control for extraneous variables, the authors analyzed how often the participants watched football, their gender, and whom they predicted to win; they found no differences between how often the participants watched football and whom they predicted to win. The hindsight bias existed for the prediction of the outcome for the Super Bowl, and the participants with previous knowledge were not immune to its effect. Results are discussed in relation to attribution theory, the reconstructionist view, and response bias view.     

Motor execution affects action prediction

Previous studies provided evidence of the claim that the prediction of occluded action involves real-time simulation. We report two experiments that aimed to study how real-time simulation is affected by simultaneous action execution under conditions of full, partial or no overlap between observed and executed actions. This overlap was analysed by comparing the body sides and the movement kinematics involved in the observed and the executed action. While performing actions, participants observed point-light (PL) actions that were interrupted by an occluder, followed by a test pose. The task was to judge whether the test pose depicted a continuation of the occluded action in the same depth angle. Using a paradigm proposed by Graf et al., we independently manipulated the duration of the occluder and the temporal advance of the test pose relative to occlusion onset (occluder time and pose time, respectively). This paradigm allows the assessment of real-time simulation, based on prediction performance across different occluder time/pose time combinations (i.e., improved task performance with decreasing time distance between occluder time and pose time is taken to reflect real-time simulation). The PL actor could be perceived as from the front or back, as indicated by task instructions. In Experiment 1 (front view instructions), evidence of action simulation was obtained for partial overlap (i.e., observed and performed action corresponded either in body side or movement kinematics), but not for full or no overlap conditions. The same pattern was obtained in Experiment 2 (back view instructions), ruling out a spatial compatibility explanation for the real-time pattern observed. Our results suggest that motor processes affect action prediction and real-time simulation. The strength of their impact varies as a function of the overlap between observed and executed actions.     

Posttraumatic Stress Symptoms of Chinese Rural Children and Adolescents Surviving the 2008 Wenchuan Earthquake Assessed Using CRIES

Posttraumatic stress symptoms in Chinese rural children and adolescents were examined after the May 2008 Wenchuan earthquake. Analysis showed that three factors were identified, namely, avoidance, intrusion, and arousal, resembling those in the studies with Western samples. Gender differences in posttraumatic stress symptoms were not significant. Moderate negative correlation coefficients between posttraumatic stress symptom scores and mental health scores were found, indicating that the more severe the posttraumatic stress symptoms, the worse the person's mental health.     

反馈时间、反馈类型和掩蔽类型对概率类别学习的影响

通过操纵反馈时间(即时,延迟)、反馈类型(简单,丰富)和掩蔽类型(塔罗牌,空白矩形),考察概率类别学习的学习机制。结果发现:(1)被试的学习成绩在即时反馈条件下显著优于在延迟反馈条件下;(2)在即时反馈条件下,仅给予简单反馈,被试虽能出色地完成天气预报任务,但是不能正确地判断卡片预测晴天的概率,倾向内隐学习;(3)在其他条件下,被试能正确地判断卡片预测晴天的概率以及各卡片在天气预报任务中预测天气的重要程度,表明被试能外显地意识到这些线索的作用。综上,概率类别学习采用的是双系统学习机制,既依赖内隐学习,又依赖外显学习。