Interfering CLEM reduces vividness and emotionality of autobiographical memories

Research background: It was noted that when people recalled an emotional event, there is a spontaneous eye movements during retrieval of memory, known as conjugate lateral eye movements (CLEM). Eye movements during mental imagery are not epiphenomenal but assist the process of image generation (Hebb, 1968; Brandt & Stark, 1997). If restricted to a fixed point, then the image of recall is impaired (Laeng & Teodorescu 2002). These findings might shed light on why bilateral eye movements during imagery could decrease vividness and emotionality of recollections. Objectives: Based on the above findings, this study examined possible therapeutic mechanism of eye movements in Eye Movement Desensitization and Reprocessing (EMDR; Shapiro, 1989, 1995, 2001), of which eye movement was a crucial treatment component. Specifically, the hypothesis that interfering CLEM via introducing bilateral eye movements or a fixed position could reduce vividness and emotionality of autobiographical memories was examined in the present study. Further, whether there are different CLEMs (more rightward in positive and more leftward in negative) during retrieval of positive and negative memories was also investigated. Method: Seventeen healthy volunteers recalled two positive and two negative memories and rated their vividness and emotionality of the recollections. Next, memories were recalled whilst the participant was performing either bilateral eye movements (interference of CLEM) or mere image condition (non-interference of CLEM). Then participants were asked to recall the event again and to rate its vividness and emotionality. Vividness and emotionality ratings were analyzed using a 2 (EM condition: bilateral eye movement vs. mere image) × 2 (valence of memory: positive vs. negative) × 2 (time: before vs. after the intervention) repeated measures analysis of variance (ANOVA). During the first and last recall of each memory CLEM were recorded by a digital camera. To examine the effect of CLEM during recollections on emotionality and vividness of autobiographical memories, eye movements in each recall were counted into percentage time of eye gaze in three regions (leftward, middle, rightward), instead of counting the first lateral eye movement as used by the traditional method. Results: Compared to mere image condition, recollections after bilateral eye movements made subsequent recollections less vivid and less emotive, while the opposite was true for mere image condition. Regarding vividness, the 2 × 2 × 2 ANOVA showed that there was a significant condition × time interaction. None of the other interactions or main effects reached significance. Simple main effect indicated that the change in vividness was significant in the mere image condition, but not in the eye movement condition. As to emotionality, the three way ANOVA showed that there was also a significant condition × time interaction. None of the other interactions or main effects reached significance. Simple main effect indicated that the change in emotionality was significant in the mere image condition, and in eye movement condition. Concerning percentage of gaze direction (left, right) in positive and negative memories, pair t test showed that there was a significant right gaze difference between positive and negative memories, and approached significant left gaze difference between positive and negative memories. With regard to CLEM, negative memories showed less right gazes and more left gazes than positive memories. Conclusion:The bilateral eye movements made autobiographical memories less vivid and less emotive than mere image condition, while mere image increased the vividness and emotionality of autobiographical memories. Further, there is different CLEM for negative and positive memories. While the hypothesis that interference of CLEM reduced the vividness and emotionality of autobiographical memories was confirmed, the role of eye movement in the EMDR was discussed and future research possibilities are proposed.

Conference

English

Sue-Hwang Chang
Yong-Ho Lee

Chang, S.-H. & Lee, Y.-H. (2005, August). Interfering CLEM reduces vividness and emotionality of autobiographical memories. Presentation at the 113th American Psychological Association Annual Convention, Washington, DC