The power of suggestion: Researchers look at why suggestive therapy may prompt false memories

February 18, 2009

(PhysOrg.com) -- Psychologist Elke Geraerts of the University of St Andrews has carried out a study of the difference between memories recalled by patients through suggestive therapies, compared with more natural recollections.

The results lead to an important distinction between two different types of recovered memories and their underlying cognitive mechanisms.

Suggestive therapy is one of a range of methods used when treating a number of conditions such as depression or anorexia, which some therapists believe may be rooted in a childhood trauma.

Dr Geraerts explained, "Some therapists conclude that their patient¿s current symptoms must be explained by a childhood trauma. Using suggestive therapy techniques, patients are either hypnotised or instructed to imagine being abused. Often, gradually over the course of several weeks or even months, the patient may finally develop memories of abuse.

"We found that, when under this sort of suggestive therapy, some people may be more likely to falsely remember that they have been abused as a child. Some people may just be more prone to suggestion and have difficulty figuring out what really happened and what has been imagined, which can obviously lead to unnecessary trauma."

Dr Geraerts believes that the study will be important in terms of supporting authenticity of reports for legal cases, though warned that "one also has to take other aspects into account like corroborative evidence for abuse. While we can show that a memory is likely to be false, we cannot be 100% certain."

The study, published in the journal Psychological Science, raises questions about why people seem to forget a previous memory of being abused. Possible triggers for spontaneously recovered memories might include a conversation about abuse, a film, a book, or other cues.

"A certain cue, such as seeing your childhood bedroom again, or seeing the perpetrator after many years, may suddenly bring back memories of abuse, Dr Geraerts explained.

"However, because people are so shocked and surprised, they incorrectly conclude that they have not thought about the abuse in years, when in fact they have somehow forgotten about previously remembering the abuse.

"This new research makes it easier as we now have found cognitive mechanisms that may lead to a certain type of recovered memory, indicating that some recovered memories reflect genuine abuse episodes for which prior memories have been forgotten."

The work points out the importance of making a distinction between memories recovered through different techniques, such as hypnosis, guided imagery (where therapists instruct clients to imagine certain scenes) and dream interpretation, and memories that were recovered spontaneously.

Dr Geraerts continued, "We believe that it is important not to be suggestive as a therapist, because some people are prone to fantasy and may imagine being abused. At some point, he/she may not be able to distinguish between what really happened and what has been imagined. However, it is important to note that not all memories recovered in suggestive therapy are false."

Provided by University of St Andrews