title: Blurring emotional memories using eye movements: individual differences and speed of eye movements.
abstract: BACKGROUND
  In eye movement desensitization and reprocessing (EMDR), patients make eye movements (EM) while recalling traumatic memories. Making EM taxes working memory (WM), which leaves less resources available for imagery of the memory. This reduces memory vividness and emotionality during future recalls. WM theory predicts that individuals with small working memory capacities (WMCs) benefit more from low levels of taxing (i.e., slow EM) whereas individuals with large WMC benefit more from high levels of taxing (i.e., fast EM).
  
  
  OBJECTIVE
  We experimentally examined and tested four prespecified hypotheses regarding the role of WMC and EM speed in reducing emotionality and vividness ratings: 1) EM-regardless of WMC and EM speed-are more effective compared to no dual task, 2) increasing EM speed only affects the decrease in memory ratings irrespective of WMC, 3) low-WMC individuals-compared to high-WMC individuals-benefit more from making either type of EM, 4) the EM intervention is most effective when-as predicted by WM theory-EM are adjusted to WMC.
  
  
  METHODS
  Undergraduates with low (n=31) or high (n=35) WMC recalled three emotional memories and rated vividness and emotionality before and after each condition (recall only, recall + slow EM, and recall + fast EM).
  
  
  RESULTS
  Contrary to the theory, the data do not support the hypothesis that EM speed should be adjusted to WMC (hypothesis 4). However, the data show that a dual task in general is more effective in reducing memory ratings than no dual task (hypothesis 1), and that a more cognitively demanding dual task increases the intervention's effectiveness (hypothesis 2).
  
  
  CONCLUSIONS
  Although adjusting EM speed to an individual's WMC seems a straightforward clinical implication, the data do not show any indication that such a titration is helpful.
authors.affiliation: Clinical Psychology, Faculty of Social and Behavioural Sciences, Utrecht University, Utrecht, The Netherlands; K.vanSchie@uu.nl.
authors.forename: Kevin
authors.initials: K
authors.lastname: van Schie
authors.affiliation: Clinical Psychology, Faculty of Social and Behavioural Sciences, Utrecht University, Utrecht, The Netherlands.
authors.forename: Suzanne C
authors.initials: SC
authors.lastname: van Veen
authors.affiliation: Clinical Psychology, Faculty of Social and Behavioural Sciences, Utrecht University, Utrecht, The Netherlands.
authors.forename: Iris M
authors.initials: IM
authors.lastname: Engelhard
authors.affiliation: Methodology and Statistics, Faculty of Social and Behavioural Sciences, Utrecht University, Utrecht, The Netherlands.|Research Methodology, Measurement and Data Analysis, Behavioral Sciences, Twente University, Enschede, The Netherlands.
authors.forename: Irene
authors.initials: I
authors.lastname: Klugkist
authors.affiliation: Clinical Psychology, Faculty of Social and Behavioural Sciences, Utrecht University, Utrecht, The Netherlands.
authors.forename: Marcel A
authors.initials: MA
authors.lastname: van den Hout
keywords: EMDR; Visual imagery; dual taxation; working memory capacity