Figure 1.
The RTs results for the between- and within-category Simon tasks in Experiments 1 and 2.
Panel A illustrates that the Simon effect (incompatible minus compatible) is a function of task type (between- and within-category color tasks) in Experiment 1. Notably, the Simon effect disappears in the within-category task but is observed in the between-category task. Panel B illustrates that the Simon effect is a function of task type (between- and within-category shape tasks) in Experiment 2. As can be seen, the RTs patterns are extremely similar to those found in Experiment 1, i.e., the Simon effect disappears in the within-category task but is observed in the between-category task. Error bars indicate ±1 standard errors of the mean (SEMs) as calculated by the pairwise difference method (SEMpairedDiff) [39].
Figure 2.
The RTs results for Experiment 3.
Panel A illustrates the RTs results for Experiment 3A with the between-category color task preceding the within-category color task. It is notable that the Simon effect is clearly observed and the RTs levels are similar in both tasks. Panel B illustrates the RTs results of Experiment 3B with the with-category color task preceding the between-category color task. Similar to Experiments 1 and 2, Experiment 3B reveals significant Simon effect in the between-category but not within-category tasks. Error bars indicate ±1 SEMs as calculated by the pairwise difference method (SEMpairedDiff) [39].
Figure 3.
The time course of the Simon effect in Experiment 3.
X-axis, mean RTs (msec), divided into six quantiles; y-axis, the Simon effect (msec), calculated by subtracting compatible from incompatible trial type. Panel A illustrates the time course of the Simon effect for Experiment 3A (the between-category color task preceding the within-category color task). It is notable that although the effect typically yields a monotonic decreasing function with increased RTs in both tasks, the slopes are distinctly different in both tasks. Panel B illustrates the time course of the Simon effect for Experiment 3B (with the task order reversed). Left: The Simon effect keeps stable at the first two bins, but almost reduces linearly at the last four bins. Right: The Simon occurs in the first two bins, whereas disappears at the third bin, even reverses by the last three bins.