Effect of post-encoding emotion on long-term memory: Modulation of emotion category and memory strength

Although studies have shown that post-encoding emotion enhances long-term memory, it is unclear whether the effect varies depending on a specific category of emotion and whether the effect depends on memory strength. In the current study, participants encoded a list of words, half of which were presented once and the remaining half of which were presented four times. Afterwards participants watched a video that was neutral, or induced one of the following emotions: anger, sadness, disgust, fear, or happiness. Overall recognition was lower in the anger-inducing condition than in the sadness-inducing or happiness-inducing condition. Recollection (i.e., adjusted rate of correctly identifying a word as old while being able to retrieve details related to the study episode) was lower in the anger-inducing condition than in the sadness-inducing condition. No significant effect of emotion was found on familiarity (i.e., adjusted rate of correctly identifying a word as old without being able to retrieve any details related to the study episode). Furthermore, memory strength modulated the effect on familiarity: Familiarity for prioritized words was lower than for non-prioritized words only in the "anger" and "sadness" conditions but not in other emotion conditions. The effect of post-encoding emotion differs depending on a specific category of emotion and modulation of memory strength relies on a specific component of recognition memory.