Can working memory account for EMDR efficacy in PTSD?

BACKGROUND: Although eye movement desensitization and reprocessing (EMDR) has been shown to be effective in the treatment of PTSD for years, it remains controversial due to the lack of understanding of its mechanisms of action. We examined whether the working memory (WM) hypothesis -the competition for limited WM resources induced by the dual task attenuates the vividness and emotionality of the traumatic memory - would provide an explanation for the beneficial effect induced by bilateral stimulation. METHODS: We followed the Prisma guidelines and identified 11 articles categorized in two types of designs: studies involving participants with current PTSD symptoms and participants without PTSD diagnosis. RESULTS: Regardless of the types of studies, the results showed a reduction of vividness and emotionality in the recall of traumatic stimuli under a dual-task condition compared to a control condition, such as recall alone. However, two studies used a follow-up test to show that this effect does not seem to last long. CONCLUSION: Our results provide evidence for the WM hypothesis and suggest that recalling a traumatic memory while performing a secondary task would shift the individual's attention away from the retrieval process and result in a reduction in vividness and emotionality, also associated with the reduction of symptoms.

[Comparative study of dyspraxia: neuropsychological evaluation of children with developmental dyspraxia or consecutive to a preterm birth]. / Etude comparative de la dyspraxie: évaluation neuropsychologique d'enfants porteurs d'une dyspraxie développementale ou consécutive à la prématurité

OBJECTIVES: The aim of the present study was to compare and contrast developmental dyspraxia and dyspraxia following preterm birth. MATERIAL: Three different domains (attention-executive function, sensorimotor and visuospatial functions) were evaluated using Nepsy battery tests and the Purdue pegboard test. METHOD: The results of a neuropsychological evaluation of 32 children with developmental dyspraxia (the DVLT group) were compared with those of 16 children with dyspraxia following preterm birth (the AP group). The population inclusion and exclusion criteria were set according to Gérard's (Gérard C-L. Le concept de dyspraxie. In: Gérard C-L, Brun V, editors. Les dyspraxies de l'enfant. Paris: Masson; 2005. p. 15-24.) definition of dyspraxia. RESULTS: The two groups had similar visuospatial performance. However, differences between the DVLT and AP children appeared in a test of attention-executive function (visual attention, specifically) and in some sensorimotor tests, with better performance by the DVLT group in all situations. CONCLUSION: The difficulties exhibited by preterm-born children (poor upper limb motor control, more severe dyspraxia and the presence of oculomotor impairments) could explain the latter's poor performance relative to children with developmental dyspraxia. Indeed, oculomotor impairments are especially likely to impair performance in visual attention and visuomotor accurary tests - the two situations in which preterm-born children performed worse.

Does the coordination of verbal and motor information explain the development of counting in children?

Counting is often considered to be the coordination of two actions: saying the number-words and pointing to each object. We report three experiments to test the hypothesis that this coordination requires the use of the central executive (A. D. Baddeley, 1990), and that the cost of coordination decreases with age. Participants were 5- and 9-year-old children and adults. At all ages tested, the manipulation of the difficulty of each component affected counting performance but did not make coordination more difficult. These results suggest that, at least from the age 5, counting is a procedure in which the control of coordination is not attention demanding.