Presentation modality effects in studying passages. Are mental images always effective ?

The present research has tested the different efficacy of imagery-based and verbally-based strategies in the study of three passages presented orally or in written form. The first passage was a description rich in easily imagined details. The second was an abstract passage, easy to verbalize, but not to imagine. The third was the spatial description of a pathway which could be both imagined and verbalized. Experiment 1 compared participants who were instructed in the use of Imagery or verbal Rehearsal while in Experiment 2 participants had high or low imagery ability. A facilitating effect of oral presentation for Imagery and high-imagery ability groups and of written presentation for Rehearsal and low imagery-ability groups were hypothesized. Data confirmed this facilitating effect and showed that it was more evident for the easier-to-imagine passages. Results are discussed in a selective interference and working memory framework. Future implications and practical suggestions are given.