No one wants to relive an embarrassing or traumatic moment, and in order to cope with these unpleasant experiences, our brains work to suppress the memories of these events.
Scientists are still looking for the mechanisms that give rise to making suppressed memories. However, the search may soon finally come to and end, as scientists from the Society for Neuroscience think they have mapped out which parts of the brain are responsible for memory suppression.
Background: How Suppressed Memories Are Made
Previous research suggests that suppressed memories are created using state-dependent learning. This process happens when an individual creates memories in a specific mental or physical state, such as being stressed or scared. Once out of that state, the individual may not be able to recall those memories, making them suppressed. The brain uses state-dependent learning as a coping mechanism to get over a traumatic experience. While this can be helpful initially, suppressed memories can also trigger anxiety, PTSD, depression, and other mental health concerns if not treated.Â
It may be hard for an individual to be treated for suppressed memories if they are not able to recall them. A study from Northwestern University suggested that to recall suppressed memories, a patient should be in a similar mental or physical state to when the memory was created. Using lab mice and probing them with a fear stimulus, the researchers were able to have the mice recall suppressed memories. While this was helpful in revealing more about the process of memory suppression, other researchers hoped to find how the process works in the human brain.Â
Analysis: Creating a Memory Map
Researchers from the Society for Neuroscience studied the memory process in 24 participants, 12 men, and 12 women, all in their 20s. Using fMRI scans, the scientists monitored brain activity while asking participants to recall words or suppress other words. During the suppression process, the researchers saw an increase in activity in the anterior cingulate cortex (ACC) of the brain. The ACC is in a unique position in the brain, as it connects the “emotional” limbic system with the “cognitive” prefrontal cortex. Because suppressed memories have been tied to both emotion and cognition, the ACC seems to be a key player in the memory suppression process. The scientists added a timing component to the suppression process and found that if a memory was not suppressed in time, the ACC generated a chemical alarm, stimulating other parts of the brain.
Outlook: New Therapies for Suppressed Memories?
While there is more research to be done, the scientists are hopeful that others can use their memory map to further understand the suppression process. The results from this study may also be beneficial to psychiatrists and therapists who are helping to treat individuals with suppressed memories. There is still more to discover, but being one step closer to solving various secrets of our brains can help us to better understand how to help heal the minds of those around us.
Kenna Castleberry is a staff writer at the Debrief and the Science Communicator at JILA (a partnership between the University of Colorado Boulder and NIST). She focuses on deep tech, the metaverse, and quantum technology. You can find more of her work at her website: https://kennacastleberry.com/