The interaction between reward and the task-irrelevant emotional context in memory

Reward improves task performance while the emotional contexts irrelevant to the task impair task performance. An interaction between reward and the task-irrelevant emotional context has been discovered by some studies using perceptual tasks. However, it is unclear that how memory performance would be affected by both variables. This study aimed to answer this question and explore the role of arousal induced by emotional stimuli, to which was seldomly paid attention by previous studies. We conducted two experiments with the study-test paradigm. The first difference between the experiments was the way that the emotional stimuli were presented. They were presented with the words (Experiment 1) or separately (Experiment 2). The second difference was that the manipulation of the emotional arousal was phasic (Experiment 1) or tonic (Experiment 2). Both experiments showed that the reward effect was greater in emotional context compared to the neutral context, which is not only due to the poorer memory of no reward-associated words but also the better memory of reward-associated words in emotional contexts especially in negative one. These results supported the view that emotional arousal enhanced the memory of high priority stimuli (reward-associated words) and impaired the memory of low priority stimuli (no reward-associated words).