The dimensional overlap (DO) theory categorizes various stimulus-response compatible effects (e.g., the manual Stroop, Simon, and SNARC effects) into two main types: stimulus-stimulus (S-S) and stimulus-response (S-R) dimensional overlap effects. The S-S type effect (e.g., the manual Stroop) occurs in the semantic-representation stage, while the S-R type effect (e.g., Simon) occurs in the response-selection stage. However, the processing stage of the SNARC effect, which is also categorized as an S-R type, remains controversial. To investigate this issue, we adopted a modified numeral parity judgment task that could simultaneously induce manual Stroop, Simon, and SNARC effects. According to the additive-factor logic, two effects occur in the same processing stage if they are interactive. In our task, we checked the interaction among the three effects to identify the locus of the SNARC effect. In two experiments with different target numbers (exp1: 1, 2, 7, 8; exp2: 0, 1, 2, 3, 6, 7, 8, 9), the manual Stroop, Simon, and SNARC effects were all observed, showing longer response times and higher error rates in the incongruent conditions than in the congruent conditions. Most importantly, only the interaction between SNARC and Simon effects was observed in the two experiments. This result suggests that the SNARC effect, as an S-R type effect like the Simon effect, occurs in the response-selection stage. In addition, the noninteraction of the manual Stroop and Simon effects and the manual Stroop and SNARC effects in our study repeatedly verifies the independence of the S-S and S-R effects. Our results further support the classification of the DO theory.

尺寸重叠（DO）理论将各种刺激-响应兼容效应（例如，手动Stroop，Simon和SNARC效应）分为两种主要类型：刺激-刺激（SS）和刺激-响应（SR）尺寸重叠效应。SS类型效果（例如，手动Stroop）发生在语义表示阶段，而SR类型效果（例如，Simon）发生在响应选择阶段。但是，SNARC效应的处理阶段（也被归类为SR类型）仍存在争议。为了调查此问题，我们采用了经过修改的数字奇偶校验判断任务，该任务可以同时引起手动Stroop，Simon和SNARC效应。根据加性逻辑，如果两个效果是交互的，则它们会在同一处理阶段中发生。在我们的任务中 我们检查了这三种效应之间的相互作用，以确定SNARC效应的源头。在两个具有不同目标编号（exp1：1、2、7、8； exp2：0、1、2、3、6、7、8、9）的实验中，均观察到手动Stroop，Simon和SNARC效应，与不一致条件相比，在不一致条件下显示出更长的响应时间和更高的错误率。最重要的是，在两个实验中仅观察到了SNARC和Simon效应之间的相互作用。这个结果表明，SNARC效应作为一种像Simon效应的SR型效应，发生在响应选择阶段。此外，在我们的研究中，手动Stroop和Simon效应与手动Stroop和SNARC效应之间的非相互作用反复验证了SS和SR效应的独立性。