Summary of Experiment 2 Design.

When three stimuli are listed (e.g., DEF+), 2nd-order occasion setting is hypothesized to be learned (except for DES- and UMS-). When two stimuli are listed (e.g., EF-), 1st-order occasion setting is hypothesized to be learned. When one stimulus is presented (e.g., F+), direct associative learning is hypothesized to be learned. All stimuli within a trial were presented serially. "+" indicates reinforcement; "-" indicates no reinforcement; "OS2" indicates 2nd-order occasion setting; "OS1" indicates 1st-order occasion setting; "Direct" indicates direct associative learning. Notably, the "DEF" family was trained in 2nd-order occasion setting before Transfer Test 1 and 2; the "UMN" family was only trained in 1st-order occasion setting before Transfer Test 1 but was trained in 2nd-order occasion setting before Transfer Test 2. This allowed the examination of whether "D" was indeed a 2nd-order occasion setter by testing "D" with "MN" before and after "MN" was trained with 2nd-order occasion setter "U." We predicted "D" would affect "MN" more strongly after "MN" was trained with "U" than before that training.当列出三个刺激项（例如"DEF+"）时，假设被试习得了二阶场合设置(2nd-order occasion setting)（DES-与UMS-情况除外）。当列出两个刺激项（例如"EF-"）时，假设被试习得了一阶场合设置(1st-order occasion setting)。当仅呈现单个刺激项（例如"F+"）时，假设被试习得了直接联想学习(direct associative learning)。试次内的所有刺激均以系列方式呈现。符号"+"表示强化，"-"表示无强化；"OS2"指代二阶场合设置，"OS1"指代一阶场合设置，"Direct"指代直接联想学习。值得注意的是，"DEF"刺激族在迁移测试1与迁移测试2前均接受了二阶场合设置训练；"UMN"刺激族仅在迁移测试1前接受了一阶场合设置训练，而在迁移测试2前则接受了二阶场合设置训练。该设计旨在检验"D"是否确实为二阶场合设置物：具体方式为，在"MN"接受二阶场合设置物"U"的训练前后，分别用"MN"对"D"进行测试。我们预测，相较于训练前，在"MN"接受"U"的训练后，"D"对"MN"的调控作用会更强。