Explore the Traces of Homunculus - Investigating the Effect of the Compound Retrieval Strategy on Switch Positivity

Previous task-switching research typically assumed that event-related potentials related to task switching, such as the target-locked switch positivity difference wave (SPDW), were indicators of cognitive control during task-set control. This study challenges that assumption. In two conventional numeric task-switching experiments (odd-even and low-high tasks), unknown symbols represented common Arabic numerals. Participants in the compound retrieval groups were unaware of the symbols' semantic meanings and relied solely on associative learning-based retrieval strategies, whereas those in the task rule groups understood the symbols and used standard task rules requiring cognitive control. Experiment 1 revealed that behavioral task-switching costs were significant only in the task rule group and completely disappeared in the compound retrieval group. However, both groups exhibited reliable SPDW without any between-group differences. Experiment 2 employed a dual-cue design to distinguish between cue-switching and task-switching. The results showed reliable cue-switch-related SPDW, while task-switch-related SPDW was not significant and showed no differences between the compound retrieval and task rule groups. Overall, there was no evidence to suggest that SPDW is a reliable marker of cognitive control. The study concluded that even if cognitive control can induce SPDW, using SPDW to represent cognitive control might not be the most appropriate approach.