The influence of sentence focus on mental simulation: A possible cause of ACE instability.

Recent studies have revealed the instability of the action-sentence compatibility effect (ACE). The current study was designed to demonstrate the hypothesis that the instability of the ACE may be attributed to the instability of focused information in a sentence. A pilot study indicated that the focused information of sentences was relatively stable in the sentence-picture verification task but exhibited significant interindividual variability in the action-sentence compatibility paradigm in previous studies. Experiments 1 and 2 examined the effect of sentence focus on the shape match effect and the ACE by manipulating the focused information of sentences using the focus marker word "" (is). Experiment 1 found that the shape match effect occurred in the original sentence, while it disappeared when the word "" (is) was used to make an object noun no longer the focus of a sentence. Experiment 2 failed to observe the ACE regardless of whether the sentence focus was on the action information. Experiment 3 modified the focus manipulation to observe its impact on the ACE using different fonts and underlines to highlight the focused information. The results indicated that the ACE only occurred when the action information was the sentence focus. These findings suggest that sentence focus influences mental simulation, and the instability of the ACE is likely to be associated with the instability of sentence focus in previous studies. This outcome highlights the crucial role of identifying specific information as the critical element expressed in the current linguistic context for successful simulation.