Cutting-edge research explores how memories can be modified after recall.

Hope for effectively treating unwanted negative thoughts may come from new techniques that can alter vivid, long-established memories.

Unwanted negative thoughts are core components of problems like addictions and post-traumatic stress disorder (PTSD).

In PTSD, people suffer from frequent intrusions of traumatic memories from, for example, a car crash or other violent event.

In addictions, people's behaviour is strongly influenced by memories of drug-taking and these motivate their future actions.

These are more extreme versions of the everyday occurrence of having flashbacks to embarrassing moments, or other painful episodes we've experienced.

But, what if it were possible to adjust memories of trauma or drug use?

According to a new review of the evidence, published in the journal Biological Psychiatry, it may be possible to more effectively target a part of the learning process called reconsolidation (Schwabe et al., 2014).

The figure below shows the typical process of learning, from the initial memory - for example, a traumatic event - through to its retrieval and alteration.
Reconsolidation is the point at which a stored memory is recalled and, according to recent research, this is the point at which it may be changed.

During the reconsolidation phase, memories become particularly unstable, and so easier to change.

Memories could perhaps be modified years after they were initially laid down.

This is effectively what many therapists try to do when they treat patients suffering from unwanted intrusive thoughts.

Patients are encouraged to recall the memory, but then the therapist tries to adjust the response to that memory.

Unfortunately, the original memory is often so strong that it is very difficult to change the response.

But, with the new understanding of the role of reconsolidation, it may be possible to make this process more effective.

It will require linking the neurobiological understanding of reconsolidation with everyday clinical practices.

Research on those with PTSD, however, has already begun to show that the use of some drugs during reconsolidation can help extinguish traumatic thoughts.

Dr. Lars Schwabe, the lead author of the study, said:
Memory reconsolidation is probably among the most exciting phenomena in cognitive neuroscience today.

It assumes that memories may be modified once they are retrieved which may give us the great opportunity to change seemingly robust, unwanted memories.