How does EMDR work?

These are the 6 main theories about how and why EMDR helps people. Research is continuing all the time to develop our understanding of how EMDR works. At present (2018), our best understanding is that EMDR could work through a combination of these effects.

All 6 theories tell us that an important part of what happens in EMDR is that we pay attention to two things at the same time (dual attention). We ‘keep one foot in the present’ (paying attention to the EMDR movement) and ‘one foot in the past’ (paying attention to the memory). When we do this, a number of things seem to happen:

• ‘It switches on the body’s calming system’ – We will instinctively and automatically pay attention to something new (researchers call this our ‘orientating response’). When we do this, after a while, our body switches on its calming system (the parasympathetic nervous system), and we can feel calmer while thinking about a difficult memory.
• ‘It stores memories away differently, similar to what happens when we sleep’ – When we sleep and dream our brain moves information between one place (our hippocampus) and another place (our semantic cortex). This is like having an organised librarian tidying up the memories from our day, and storing them away. When we store a traumatic memory, it is not stored in a tidy, helpful way in our brain. EMDR seems to switch on our organised librarian to tidy up the traumatic memory, and store it away, linked with more helpful information.
• ‘It turns down the part of the brain that controls the emotional strength of the memory, similar to what happens when we sleep’ – When we are in a particular stage of sleep (slow wave sleep) a part of our brain that controls the emotional strength of a memory (the amygdala) gets ‘turned down’, which means the memory can be stored away differently, and linked to more helpful information. EMDR seems to do the same thing, helping us store away traumatic memories in a more helpful way.
• ‘It helps us to link information together again’ – All information coming into our brain (apart from smell) comes in through a gateway (the thalamus). This gateway helps us to link information coming into the brain, with things that we have stored away already. When we have traumatic experiences this gateway does not work very well, and information does not get linked up with things that we know already. EMDR seems to help the gateway to do its job, and link up this information.
• ‘It lets us take a step back and watch’ – Dual attention seems to help us to look at a memory from a distance, without getting lost in the emotions, or feeling that the memory is happening right now. Researchers call this ‘metacognitive awareness’ or ‘mindfulness’. It seems that the part of our brain that helps us control our attention (prefrontal area) is able to move our attention in a helpful, flexible way.
• ‘It gives our working memory something to do’ – EMDR gives our ‘working memory’ something else to do while we are thinking about the traumatic memory. This appears to reduce the quality of the traumatic memory, so that it is less vivid and triggers less emotion.

Based on article: Murray, G. (2018). ‘How Does EMDR work?’. European Journal of EMDR Therapy, Vol 1, No 1, p17-22.

EMDRinfo/JJ/Sept2018