Valenced dual tasking in PTSD patients

Analogue lab models of EMDR have shown that emotionality and vividness of aversive memories decrease by engaging in a taxing working memory task while the memory is activated. In the recent years, studies that add valence to the dual tasking model have shown promising results. With this study, we aim to take the lab findings to clinical practice and research the benefit of enhancing a dual tasking session by adding positive valence to the secondary task in PTSD treatment.

We expect that emotionality and vividness of traumatic memory will be decreased most in the positive dual tasking condition.

We will collect data on several time points (the intervention consists of one intervention session only and the patient may choose to have all measures (but the primary outcome measure, the VAS) in an earlier session or just before the intervention session):

Right before the intervention: Emotionality and vividness of the memory (pre measure Visual analogue scales), working memory (WAIS Digit Span), Self-esteem (Rosenberg Self Esteem Scale), demographic and other baseline characteristics (Posttraumatic Diagnostic Scale-V, Symptom Check List-90).

After each intervention: Emotionality and vividness of the memory (post measure Visual analogue scales)

All patients receive all three conditions in randomized order in one session:

- Positive dual tasking: Participants bring to mind (alternating between assisted and unassisted recall) the most distressing image (the hotspot) of their traumatic memory, while simultaneously rating positive pictures in 8 sets of 1 minute (4 sets per one block). This brings about competition in the working memory, leading to decrements in emotionality and vividness ratings (which is theorized to be the working mechanism of EMDR). Based on previous literature, we expect positive valence to amplify these effects on top of the general ‘dual tasking effect’.

- Neutral dual tasking: Same as above, but with neutral pictures.

- Exposure only: Participants focus on a fixation cross, while keeping their most distressing image in mind. Exposure times are kept equal to the other two conditions.