Must you keep recalling a negative memory during demanding dual-tasks to reduce its vividness and emotionality?

Details

In Eye Movement Desensitization and Reprocessing (EMDR), a patient recalls a traumatic memory while simultaneously performing a dual-task, such as making horizontal eye movements or tapping a pattern. Earlier laboratory studies found that increasing the load of a dual-task, leaving fewer resources for memory recall, produced larger decreases in memory vividness and emotionality than control conditions. The researchers investigated whether continuous, deliberate memory recall is necessary while performing highly demanding dual-tasks.

In two online experiments, participants (N = 172 and N = 198) recalled a negative autobiographical memory and were randomly assigned to memory recall plus dual-tasks, dual-tasks only, or a no-intervention control. The dual-tasks were complex pattern tapping and spelling out loud. Participants rated the memory's vividness, emotionality and accessibility before and after the intervention.

Compared with the control, highly demanding dual-tasks produced the largest reductions in all three measures, regardless of whether participants continuously recalled the memory. Unexpectedly, there was no evidence that adding continuous memory recall increased these reductions. The results suggest that continuous memory recall may not be needed, or may be needed only minimally, for the beneficial effects of the dual-task procedure. The researchers discuss the necessity of memory reactivation, alternative explanations and implications for practice.