Prediction-based false memory: Unconfirmed prediction can result in robust false memories

A growing body of literature suggests a powerful role of predictions on memory through prediction violation and prediction confirmation. Violation appears to enhance memory for the event violating the prediction, meanwhile, confirmation boosts memory for the predicted event instead. Crucially, however, the effect of prediction by itself has not been identified as it has typically been studied with its violation or confirmation. Here, we demonstrate the power of explicit predictions on memory by isolating it from its direct violation and confirmation. In a series of experiments, participants were presented with a real-world object along with three characters and they predicted which character the object belonged to. Upon prediction, participants received either visual confirmation (predicted character showing the item), visual rebuttal (another character showing the item) or no feedback (none of the characters showing the item) with regard to their prediction. When their memory was tested, participants were more likely to falsely remember that their predicted character showed them the item than the other characters did, even when no feedback was provided. This false memory was not eliminated by visual rebuttal and it was not weakened when participants had a strong item memory. Experiments 2-4 eliminated action (selecting a predicted character) as an alternative explanation and demonstrated that this prediction-based false memory could be modulated through indirect prediction confirmation and rebuttal. Taken together, our findings show that explicit predictions can be sufficient to induce false memory of predicted events that are robust enough to withstand its direct rebuttal.