Comparisons of eye movements and matched changing visual input.

BACKGROUND AND OBJECTIVES: During EMDR trauma therapy, performing EM taxes WM, and simultaneously recalled memories become less vivid. It has been proposed that this WM occupation results from CVI which occurs during EM. This study sought to compare the effects of EM on memory to a task presenting identical visual stimulus to stationary eyes..

METHOD: In Study 1, participants recorded RT while performing two tasks: EM, and a task with visually identical images displayed on screen. In Study 2, these same tasks were performed while simultaneously recalling negative emotional memories.

RESULTS: Study 1 found RT was slowest in the EM condition, while RT in the CVI condition was still slower than in the control condition. Study 2 found decreases in memory vividness and emotionality after EM, while after CVI there was a small decrease in negativity which was not greater than in the control..

LIMITATIONS: Neither study included EM with no visual input; conclusions cannot be made about the effect of motor movement on WM taxation or recall. As neither study was conducted with trauma patients, it is unknown if the observed effects would be comparable in the population for which EMDR is intended.

CONCLUSIONS: Performing EM taxes more WM resources and has greater impact on both memory vividness and emotionality than matched CVI. This demonstrates that the effects observed in EMDR treatment are the result of more than occupying WM systems with visual stimuli alone..