Peters investigated the malleability of emotional memory, particularly fear memory in people with a spider phobia. Unlike previously believed, fear memory can be altered, opening the possibility for more effective treatments for anxiety and phobias. “We tested a reconsolidation-inspired intervention, which is a treatment designed to weaken fear memory directly. This has the exciting potential to prevent a return of symptoms, which – if proven successful – could revolutionize treatments for phobias and other related mental health conditions” 

Emotional memory

Emotional memory helps us learn from both positive and negative experiences. For example, think of a child who gets bitten by their aunt's dog. After this experience, the child will likely become more cautious around dogs. This kind of memory helps to protect us. However, emotional memory can also become dysfunctional and trigger strong fearful reactions that are out of proportion to the actual danger. If your fear of your aunt's dog generalizes to all dogs, it could have developed into a phobia. Such dysfunctional fear memory can then also contribute to avoidance behaviour, so that you cannot enjoy places anymore where dogs are often found, like parks.

Reconsolidation-inspired Interventions

One of the novel treatments for anxiety disorders are reconsolidation interventions. When a memory is reactivated, for example by confronting a spider under specific conditions, it can become briefly unstable and is then re-stored. This process is called reconsolidation and occurs in the brain. At this moment of instability, there is an opportunity to change the emotional charge—both positive and negative—of the memory. Successfully interfering with reconsolidation is thought to strongly reduce avoidance behaviour after a night of sleep.

In an experiment with people with spider phobia, the effectiveness of a reconsolidation intervention was examined by Peters and colleagues.  "We tested whether the reconsolidation intervention was more effective than a control condition in individuals with spider phobia. This was previously tested for sub-clinical fear in a different experiment in our research group, the Amsterdam Emotional Memory Lab, led by Merel Kindt.”

“In the present study, we had both groups confront a tarantula in a so-called memory reactivation procedure, which was then either immediately followed by the amnesic agent or an identically looking placebo pill. Then, participants re-encountered spiders two days after this initial treatment, when we measured their avoidance behaviour. A third group also received the reconsolidation intervention, but only re-encountered spiders one month after their treatment, so that we could test whether a re-confrontation within days after the initial treatment was important for treatment success.”

“We found that the reconsolidation intervention was not more effective than placebo in the short-term, but more effective in the long-term. Re-encountering spiders within days after the initial treatment was vital.”

Spider Distress Scale

Peters and colleagues also developed a new measurement tool, the Spider Distress Scale. This questionnaire measures not only the fear of spiders but also the disgust people may experience towards spiders. "Although not directly related to our treatment study, improving the tools with which we can monitor changes over the course of treatment can help to eventually improving our current interventions.”

“Spider fear is an excellent model to study treatment mechanisms in phobias and other anxiety disorders as the fear-evoking cue is quite specific. While more specific fears exist, they are more challenging to study in a laboratory setting. In contrast, spider fear is both highly prevalent and practical for research, as the phobic stimuli are easy to maintain and can be presented to participants in various sizes.” Explains Peters.

Treatments

Reconsolidation interventions hold promise for treating anxiety disorders, but they are not a holy grail for instant symptom relief. “Reconsolidation interventions were initially thought to be a single-session treatment, consisting of the ‘memory reactivation procedure’, in combination with the amnesic agent. We found that re-encountering the feared cue within days after the reconsolidation treatment is a critical addition to the treatment protocol. Experiencing the behavioural change during this re-confrontation may be important to update fear-related beliefs and thereby solidify changes in fear. A single-session reconsolidation treatment might be overly optimistic for addressing clinical fears effectively.”

Peters' research findings provide insights for improving treatments for anxiety disorders and PTSD. By demonstrating that emotional memories are malleable, it opens the door to new treatment methods that could be more effective and less burdensome. "Controlled research on reconsolidation interventions in clinical populations is still in its infancy, there is so much more to explore. Under which conditions can reconsolidation be triggered so that the memory becomes malleable? How much of these exciting findings are attributable to reconsolidation interference compared to placebo effects? Of course, our ultimate goals is to support individuals suffering from phobias and traumatic experiences by effectively translating insights from fundamental and clinical research into practical treatments.”

Promotion details

Dr. Jack Peters' dissertation, titled The Malleability of Emotional Memory: Modification and Measurement, supervisor is Prof. M. Kindt, co-supervisor is Dr R.M. Visser.