Subject groups.

Subjects were first objectively divided into two groups a priori according to their performance on the task as represented by the accuracy score listed here. Of 39 total subjects, 20 were classified as “Good-learner” subjects for whom choice accuracy was significantly greater than the chance score of 50% at the level of an individual subject (p < 0.05). Of the remaining 19 “Poor-learner” subjects, 4 were subsequently reclassified as “Nonperformer” subjects in cases of complete insensitivity to outcomes, which was verified with computational modeling. There were no significant differences between the two main groups when considering possible confounds in reaction time (RT), the total number of missed trials following errors, or age and gender (p > 0.05). Standard deviations are listed in parentheses by the corresponding means within groups.

首先，研究对象依据此处列出的准确率得分所体现的任务表现，先验地被客观划分为两组。总共有39名研究对象，其中20名被归类为“良好学习者（Good-learner）”组：在个体水平上，该组的选择准确率显著高于50%的随机猜测水平（p < 0.05）。剩余的19名为“较差学习者（Poor-learner）”组，其中4名因对结果完全无敏感性，经计算建模验证后，被重新归类为“无表现者（Nonperformer）”组。在考虑反应时（reaction time, RT）、错误后遗漏试次总数，以及年龄、性别这些潜在混淆变量时，两个主要群体之间均无显著差异（p > 0.05）。各组的均值旁以括号标注了对应的标准差。