A new study pokes holes in the popular theory, originating from Sigmund Freud, that suppressed memories, like those from a traumatic event, remain intact and can negatively influence behavior and mental health.
But according to a study published in the journal PNAS, suppressing unwanted memories actually interferes with the brain's activity and reduces the likelihood that the event unconsciously influences a person's behavior.
Researchers from the Medical Research Council (MRC) Cognition and Brain Sciences Unit and the University of Cambridge's Behavioural and Clinical Neuroscience Institute (BCNI) had participants learn a variety of picture-word pairs while hooked up to functional magnetic resonance imaging (fMRI) that monitored their brain activity. After learning the picture-word pairs, the participants were asked to either think of the image that corresponded to a word or to suppress the memory of the image and its corresponding word.
Next, participants were asked to identify objects that were visually distorted and displayed for a brief amount of time. Participants had a harder time identifying the objects they had suppressed compared with those they had not. Brain imaging showed that suppressing memories of the objects interfered with activity in the brain's visual areas, leading researchers to conclude an "out of sight, out of mind" effect. The suppressed memory, according to the brain imaging, doesn't remain intact, making it less likely that it affects our behavior in a Freudian way.
If suppressing traumatic memories as a coping mechanism can actually help, these findings may be able to help psychologists treat patients with traumatic memories, and could contribute to further research on issues like intrusive memories, which are common among people suffering disorders like PTSD.