Chilling and Blurring of Negative Memories: A Quasi Experimental Study

Background and Aim : This study is based on the Memory Process Theory and examined whether interventions during encoding and retrieval phases, could reduce physiological (heart rate and blood pressure) and subjective (vividness and emotionality) responses to negative memories.Methods : 95 non-clinical participants (age 20-30) were randomly assigned to three groups including: control (n=30), expanding attentional span (EAS) (n=33) and working memory interference (WMI) (n=32). Before watching a 5-minute movie clip eliciting negative emotion, participants in EAS condition were asked to highly allocate attention to peripheral aspects of the main event, since they might be asked about the details later. After watching the movie, participants were asked to select the most traumatic scene of the movie to be recorded by examiner. Participants returned to the lab after 24 h for retrieval phase when they were presented with the previously selected traumatic scenes. They were asked to remember the movie while their eyes were closed and rated the vividness and emotionality of the mental images. While all the groups were engaging in retrieving memories, the WMI group was asked to perform a visuospatial memory task (making shapes with matches). Following the filler task, all the participants were re-asked to remember the movie while rating the vividness and emotionality. They were also asked to rate the Self-Assessment Manikin (SAM) scale. Heart rate and blood pressure were also recorded. Data were analyzed using t-test and ANCOVA.Results : Our results indicate no difference in terms of physiological responses between groups, while in terms of subjective responses, the EAS group reported significantly lower emotional dominance (F=4.93, P=0.03) compared to the other two groups. Moreover in terms of memory vividness, the WMI group achieved significantly lower score than the other two groups (F=5.33, P=0.02).Conclusion : The present study revealed the importance of attention direction and working memory interference in decreasing subjective response towards memories which trigger negative emotions.

Keywords:

Negative memories , Emotional response , Expanding attention , Working memory interference