Reversing Reciprocal Suppression in the Anterior Cingulate Cortex: A Hypothetical Model to Explain EMDR Effectiveness

A theoretical model is proposed to explain desensitization during Eye Movement Desensitization and Reprocessing (EMDR) as resulting from the reversal of reciprocal suppression of cognitive processing in the anterior cingulate cortex (ACC). Dual-attention and error monitoring are known to activate dorsal regions of the ACC that mediate metacognitive processing. Neuroimaging research has produced evidence that cognitive areas in the upper ACC may reciprocally suppress affective processing in the lower areas and vice versa. It is therefore proposed that the original eye-to-finger tracking task of EMDR may achieve its therapeutic effect by using error monitoring to reverse suppression of the upper ACC by the lower ACC. Contributions to EMDR effectiveness from resource installation and novelty-driven orienting reflexes may also influence ACC functioning. A distraction effect is proposed to be a negative and potentially disruptive by-product of very interactive stimulation tasks. A semantic priming procedure is suggested to limit distraction effects during more interactive forms of stimulation. When Francine Shapiro initially published her EMDR protocol for treating Post-Traumatic Stress Disorder (PTSD) in 1989, eye movements were hypothesized to be the catalytic ingredient to stimulate accelerated information processing. Since that time, many EMDR trainers and consultants have used alternating bilateral stimulation (ABS) as a more liberal interpretation of the catalytic stimulus. The use of numerous forms of ABS (e.g. auditory tones, vibrations, hand taps, etc.) is now widely accepted by EMDR clinicians. It is assumed that they all are effective forms of sensory stimulation because they alternate bilaterally. What is lost in this evolution is that the EMDR eye movement procedure is a visual-tracking task in the context of a performance expectation. It demands effortful divided attention. The patient is required to synchronize his or her gaze on a moving target while concurrently thinking about the target memory. In addition, the therapist's obvious scrutiny of the patient's gaze and the therapist's periodic verbal encouragement " paint " the patient's efforts with a sense of importance. All of these factors have neurological effects. From the standpoint of psychophysiology, such a performance task is a very different phenomenon than the passive reception of non-task-related sensations. By emphasizing eye movements and bilateral stimulation, the proponents of EMDR have drawn attention away from the informational dimensions of the methods used. Task relevance, novelty, ambiguity, complexity of stimulus information, social context, public exposure, relevance to the targeted memory, and load demand on short-term memory are just a few …