Implementation intentions and imagery: individual and combined effects on prospective memory among young adults

Prospective memory (PM) has been found to benefit from implementation intentions (i.e., "when I see X, I will do Y"). However, to date, it is unclear whether implementation intentions must incorporate imagery in order to produce a positive effect on PM, or whether the verbal statement alone is sufficient. It is also equivocal whether the use of visual imagery alone improves PM, absent an intentional statement. The present study investigated the individual influences of implementation intentions and imagery, as well as their combined effect, on PM. A total of 64 undergraduates were placed into one of four instructional conditions-read-only, implementation intention, imagery, or combined-and were then tested on a laboratory PM task. The results revealed that participants in the implementation intention, imagery, and combined groups completed significantly more PM tasks than did participants in the read-only group, but they did not differ from one another. Combining implementation intentions and imagery, however, did not improve PM performance over either strategy alone. Additionally, the implementation intention and imagery groups outperformed the read-only group on a secondary ongoing digit detection task. The results of this study suggest that implementation intentions do not require imagery to be effective in improving PM, and that imagery alone has positive effects on PM. Finally, the results of the ongoing digit detection task suggest that the use of implementation intentions and imagery might provide for automatic identification and processing of environmental cues.