Effects of emotional ambiguity and emotional intensity on true and false memory.

Whereas the effects of emotional intensity (the perceived strength of an item's valence or arousal) have long been studied in true- and false-memory research, emotional ambiguity (the uncertainty that attaches to perceived emotional intensity) has only been studied recently. Available evidence suggests that emotional ambiguity has reliable effects on true memory that are distinct from those of emotional intensity. However, those findings are mostly restricted to recall, and the effects of emotional ambiguity on false memory remain unexplored. The current study addressed both limitations by measuring the effects of emotional ambiguity and emotional intensity on true and false recognition. In two experiments, we manipulated valence ambiguity and valence intensity (Experiment 1) and arousal ambiguity and arousal intensity (Experiment 2) of Deese/Roediger/McDermott lists. Multiple linear regression analyses were conducted for Experiment 1, Experiment 2, and the combined data of the experiments to separate the effects of emotional ambiguity and emotional intensity. Our results showed that both valence ambiguity and arousal ambiguity improved true recognition, and the effects of valence ambiguity remained robust even when controlling for valence intensity, arousal intensity, and arousal ambiguity. More importantly, for both valence and arousal, there was an interaction between ambiguity and intensity in false memory. Specifically, we found that valence ambiguity increased false recognition with positive valence, while arousal ambiguity amplified the effect of arousal intensity on false recognition. Our results are discussed in the context of the emotional ambiguity hypothesis and fuzzy-trace theory.