Recent research performed at the University of Colorado at Boulder has suggested that people have the ability to suppress emotional memories with practice. Brendan Depue, Marie Banich and Tim Curran (2007) highlighted the importance of this study, discussing its implications for those suffering from conditions ranging from post-traumatic stress disorder to depression.

As part of the method, participants were asked to memorise 40 different pairs of pictures, each pair showing a human face (cue) and a disturbing picture (target) such as a car crash or a wounded soldier, among many others.

The participants were then given special viewing glasses that showed only the face images. At this stage they were placed in MRI scanners to record brain activity. On some trials, they were asked to think of the picture associated with the face, on other trials they were instructed to not let the associated picture enter consciousness.

The brain scans recorded during this process indicated the coordination for memory suppression occurred in the brain's prefrontal cortex which is known to be associated with cognitive control. Brendan Depue, Marie Banich and Tim Curran found that two regions of the prefrontal cortex seemed to suppress certain areas of the brain involved in tasks like visual recall, memory encoding and retrieval, and emotional output.

The study showed that the participants were able to control their emotional memories to a certain extent by shutting down certain parts of the brain through repetitive practise. In this way, participants were able to stop the retrieval process of some emotionally loaded memories. This has great implications for future practise associated with many clinical disorders such as post traumatic stress disorder, depression, chronic anxiety and phobias. On the other hand, the idea of emotional suppression is still controversial and deemed dubious by many.

(Taken from: Depue, B., Banich, M., & Curran, T. (2007). Prefrontal Regions Orchestrate Suppression of Emotional Memories via a Two-Phase Process. Science, 317, 215-219).

In another study performed by Bonanno, G., Papa, A., Lalande, K., Westphal, M., & Coifman, K. (2004), emotions were examined in the form of expression. In this study participants’ performance in a college laboratory task was observed where they were to exert enhanced emotional expression, suppressed emotional expression, and behave normally on different trials. The participants gathered for the study were New York City college students who experienced the aftermath of the September 11th terrorist attacks.

Participants involved in the study were shown images on a computer screen and asked to express or suppress the emotions felt as associated with each image. In some cases they were asked to act normally in response to viewing the images. In the case of emotional expression, participants were asked to show their emotion so that others may guess what it was they were feeling. In some cases they were asked to suppress their emotional expression so that it would be difficult for observers to identify their emotions. Lastly, participants were told that there was nobody observing them, in which case they were able to act normally.

After completing these tasks the participants were given a memory task involving the images observed on their computer screens. Four questions were asked about each picture: half to emotional details and half to non-emotional details. Distress of participants was recorded one month of beginning college and again at the end of the second academic year.

Results found that subjects who were better able to enhance and suppress the expression of emotion showed less distress as recorded two years after the initial test. The research highlighted the importance of emotional flexibility and management in order to reduce distress and anxiety.

(Taken from: Bonanno, G., Papa, A., Lalande, K., Westphal, M., & Coifman, K. (2004). The Importance of Being Flexible The Ability to Both Enhance and Suppress Emotional Expression Predicts Long-Term Adjustment. Psychological Science, 15, 482-487)