Imagery processing is necessary for the subject-performed task effect: Evidence from event-related potentials

Abstract

Studies have shown that eliciting the subject-performed task (SPT) effect requires imagery involvement, but the role of imagery in this effect is still unclear. Therefore, this study used behavioral and event-related potential (ERP) technology to explore the role of imagery in the SPT effect. The experiment used a within-subject design with 3 encoding types (performance, imagery, and verbal) × 2 levels of imagery (high and low). The results of Experiment 1 revealed that the memory performance of both performance encoding and imagery encoding was significantly greater than that of verbal encoding, indicating the existence of the SPT effect, and verb–noun phrases with a high-imagery level had a greater SPT effect than low-imagery phrases. Experiment 2 adopted the same experimental design, utilizing behavioral and ERP techniques, and found that the behavioral results were consistent with those of Experiment 1. The ERP data revealed that in the performance and imagery encoding conditions, greater late positive components were observed for high-imagery phrases than for low-imagery phrases, which indicated that imagery processing is the key factor in the generation of the SPT effect. The current study confirmed that imagery is necessary for the generation of the SPT effect and that the size of the SPT effect is dependent on the imagery level of the phrase.