Date Published: August 20, 2018
Publisher: Public Library of Science
Author(s): Bo Wang, Ulrike Rimmele.
Although studies have examined the effect of emotional stimuli on reality-monitoring source memory, it is poorly understood whether the effect observed would remain if emotion is induced after encoding. In addition, although there has been evidence that post-encoding emotion enhances item memory but not external monitoring source memory, it is unclear whether such a null effect extends to other types of source memory. To address these gaps, in the current study, participants encoded a list of words. For half of the words they were asked to think about the corresponding opposite words, and for the remaining half of words they viewed the corresponding opposite words. Following encoding they watched a neutral, positive or negative video. Replicating prior studies, both positive and negative emotions enhanced consolidation of item memory. Furthermore, participants at a high level of state anxiety, trait anxiety and depression were more likely to benefit from the enhancement effect of post-encoding emotion. However, no significant effect was observed on reality-monitoring source memory. Taken together the current study suggests that the enhancement effect of post-encoding emotion on item memory does not necessarily extend to reality-monitoring source memory.
Item memory refers to memory for an event itself (e.g., meeting a friend) , whereas source memory refers to memory for the contexts under which the memory was acquired (e.g., the place or time for meeting a friend) . Source memory can involve three types of monitoring: external monitoring (i.e., discriminating sources of external information), internal monitoring (i.e., discriminating sources of internal information) and reality monitoring (i.e., discriminating sources of external and internal information) . In everyday life it is of critical importance to have accurate reality-monitoring because it provides the basis to minimize distortion in retrieving origins of information. For instance, it is important to distinguish between the memory of locking a door and the memory of just imagining locking it. According to the framework by Johnson, Hashtroudi and Lindsay , the basis for being able to discriminate between a real event and an imagined one is that the former contains more sensory, perceptual and semantic details whereas the latter contains more information regarding cognitive operations.
The goal of the current study was to examine whether post-encoding emotion would enhance consolidation of both item memory and reality-monitoring source memory. Replicating the findings from a series of prior studies [e.g., 11, 12], post-encoding emotion enhanced consolidation of item memory (via decreasing false alarm rates). Nonetheless, no enhancement effect on consolidation of source memory was observed. Thus the current study, while replicating prior studies, contributes to the literature by indicating that the enhancement effect of post-encoding emotion does not extend to all aspects of memory.