External reward and intrinsic motivation jointly influence memory. While studies have shown that rewards diminish the effect of motivation on memory, rewards usually come before motivation, leaving a gap in understanding their interaction when rewards are presented afterward. Researchers at Peking University, Beijing, investigated how the timing of reward cues directed the interaction between external reward and intrinsic motivation on memory over time.
In this study, participants viewed short film clips because they are vivid and vary in interest for individuals, closely mimicking natural experiences in daily lives. Participants then rated their interest and completed memory tests 10 minutes later and 1 day later in both experiments, with an additional 1-week delay included for Experiment 1. To replicate the interactive effect observed in previous studies, reward cues in Experiment 1 were presented before the participants viewed the film clips and rated their interest levels. In Experiment 2, reward cues were presented after the participants viewed the clips and rated their interest in order to separate the timing of reward from interest and explore the predicted additive effect on memory over time.
The researchers found that when cued before clips, rewards improved memory and reduced forgetting for the low-interest clips, therefore decreasing the interest effect on memory. However rewards increased forgetting for high-interest clips suggesting that the “undermining effect” (the phenomenon that external reward for an initially enjoyable task reduces later internal motivation for the task) is time-dependent and requires strengthening during sleep.
On the other hand, when cued after clips, rewards improved memory and reduced forgetting for the high-interest clips, therefore increasing the interest effect. In other words, early rewards boost memory for uninteresting content, while later rewards boost memory for interesting ones. Researchers suggest this helps explain how outside rewards and inner motivation work together over time to affect memory.
StepUp Note
Parents tell us that the “first work, then play” strategy is the most important thing they have learned in helping their child become an independent learner. This research tells us why. Giving a child something to look forward to, before doing something challenging or non-preferred, helps them stay motivated to finish their work and earn their play time. In StepUp, children look forward to earning their puzzle badges after they complete each day of daily practice exercises.
Note by Nancy W Rowe, MS, CCC/A