INTRUSIVE MEMORIES | Prof. Emily A. Holmes

When we experience psychologically traumatic events, (that is events where we feel under threat from harm- real or imagined), our brain takes in information differently. Our understanding of why this happens is that the brain in part is trying to help the person cope with the situation better, but it is also trying to store up the experience for later learning. The knock-on effect is that after such events, some people are left with what we call intrusive memories.

Intrusive memories are pop up memories (usually visual images) of the traumatic event that spring into mind, usually with strong emotions. It is as if your brain wants you to keep thinking about what happened, and it keeps the memory at the front of your mind. Intrusive memories appear like brief pictures in our mind’s eye.

It is often uncomfortable to experience intrusive memories. They can be quite hard to talk about, and make sense of, and people usually don’t want the feelings that they come with. There are several other knock-on effects- people will often feel that it keeps them in a state of alertness where they feel ready for the next bad thing to happen, which can make people anxious or irritable (or both), and they can disrupt sleep. Our instinct is to avoid anything that might trigger the memories, and so over time individuals might withdraw from activities they might like or need to do. This can impact mood and enjoyment and can lead to social isolation.

With many thanks to Dr. Julie Highfield.

Using an Imagery-Competing Task Intervention (ICTI) to Target Intrusive Memories after trauma.

So, we want to target those intrusive memories, and help your brain put them away in the memory store of your mind and no longer pop up with strong emotion. And our research indicates we can do this without having to talk about what happened in any detail.

We do this through a guided series of intervention components, that include a digital task (a computer game).

• First, we’ll ask you to write a list of the intrusive memories- pictures that keep popping into mind.
• Then we’ll ask you to keep a tally of those over a week.
• Then we’ll show you how to play the computer game Tetris^® in a slightly more advanced way- instead of just playing it we’ll get your practicing imagining moving the blocks around in space before they land in the holes (mental rotation). This gets your brain in a visual rather than verbal mode.
• We’ll ask you to briefly bring one of your intrusive memories into mind, and then play Tetris^® in the way we instructed for about 20 minutes.

You can repeat this with each intrusive memory.

The aim is to stop them intruding to mind.

It is better not to just “play Tetris^® ” as our research suggests playing Tetris^® alone is unlikely to be helpful – you need a bit of help to identify the intrusive memories, bring them to mind just briefly, and play Tetris in the specific way.

Our research has shown FOR EXAMPLE that people who experience more than 3 intrusive memories a week can reduce this to one or none after a few weeks of following this process. More research is needed as we continue to develop this.

For Clinicians:

If you are a practicing psychological therapist, you might wonder how you can utilise this tool in your day-to-day practice with your clients. First, let us reassure you, we are not trying to replace talking therapies! We do know, however, from interventions such as EMDR, that trauma is not all verbally stored or accessible, and visual tools can help some of our client groups. ICTI is a proactive self-processing technique, where the person brings to mind the picture, whilst using Tetris^® with mental rotation. So, we hope in the future your client can use it in session with you, or as a between session homework exercise.

What are the Risks?

Our research so far shows that people like the approach (Patel et al., 2024; Ahmed Pihlgren et al., 2024) and some find it helpful not having to talk in any depth about their intrusive memories. Our recent trial (Iyadurai et al., 2023; Ramineni et al., 2023) indicate the intervention is safe and like all treatments this should continue to be monitored.

With many thanks to Dr. Julie Highfield.

If you or someone you know is experiencing intrusive memories and possible PTSD, here is some information for the public to which we have contributed in Sweden:

1177 Vårdguiden

Page 29 – a description the symptoms of PTSD, see here

Page 30 – a summary of PTSD treatments, see here

For more detailed reviews in Swedish that may be of particular interest to clinicians and healthcare providers, here are two reports from SBU (Swedish Agency for Health Technology Assessment and Assessment of Social Services):

Evidence-based review for the treatment of PTSD

Statens beredning för medicinsk och social utvärdering. (Swedish Agency for Health Technology Assessment and Assessment of Social Services). (2019). Psykologisk, psykosocial och annan icke-farmakologisk behandling av posttraumatiskt stressyndrom (PTSD) hos vuxna (SBU-rapport 127). Stockholm: https://www.sbu.se/2019_12
(Psychological, psychosocial and other non-pharmacological treatment of post-traumatic stress disorder (PTSD) in adults)

Evidence-based review the prevention of PTSD

Statens beredning för medicinsk och social utvärdering. (Swedish Agency for Health Technology Assessment and Assessment of Social Services). (2019). Psykologiska, psykosociala och andra icke-farmakologiska insatser för att förebygga posttraumatiskt stressyndrom (PTSD) hos vuxna (SBU-rapport 233). Stockholm. https://www.sbu.se/2019_11 (Psychological, psychosocial, and other non-pharmacological interventions for the prevention of post-traumatic stress disorder (PTSD) in adults)

Please note that the treatment we have been developing (imagery competing task intervention) is still being researched and not yet available nor in the current guidelines.