The Role of Emotions in Memory Formation


Emotional Memories: Researchers have discovered that our emotional inner world significantly influences how we store memories of an experience. Our memory tends to create division when our feelings suddenly change in a situation. This mechanism could potentially aid in the improved treatment of traumas, as reported in Nature.

Every day, we encounter numerous situations, but not all of them are etched into our memories. The limited space within our minds forces the prioritization of particularly relevant events. These are frequently events that elicit strong emotions, such as a marriage proposal or the death of a pet. Even years later, we can vividly recall such memories, while mundane and neutral events, like the last dinner or a trip to the supermarket, fade into obscurity.

The brain’s emphasis on strong emotions is rooted in the survival strategy of our ancestors. Remembering a predator attack that survived teaches us to avoid such dangerous situations in the future. Simultaneously, the joy we feel when consuming delicious berries aids in the ongoing search for quality food.

Boxes and Dividers in Memory

When storing experiences in our memory, we compartmentalize them, akin to organizing episodes in a sitcom. This segmentation creates manageable chunks that help structure and retrieve our memories effectively. “It’s like putting items into boxes for long-term storage,” explains David Clewett from the University of California in Los Angeles. “When we need to retrieve a piece of information, we open the box that holds it.”

For instance, a humorous conversation with a best friend goes into one box, and the exciting movie watched with them goes into another. External context, such as passing through a door, influences the division of these memory chunks—literal “dividers” between memories.

Psychologists have long suspected that internal context, the emotions experienced during an event, also influences dividers between individual episodes.

Emotional Picture Stories

To examine the role of emotions, Clewett and researchers conducted a memory test with around 70 participants. They were shown various pictures on a computer screen, like a slice of watermelon, a wallet, or a soccer ball.

Participants were tasked with creating a story connecting the different images. Importantly, they listened to specially composed music, inducing joyful, anxious, sad, or calm feelings during the experiment. A day later, participants were asked to recall the sequence of the images. By combining what participants remembered with the accompanying music, researchers inferred how emotions affected memory formation.

Creating Dividers Through Emotional Shifts

Results revealed that shifts between different emotions notably influenced memory formation. Whenever participants’ feelings changed, a mental divider formed, distinguishing various memory episodes. For example, they could group all images seen during sad music into one episode. When the melody shifted to cheerful music, a new episode began in participants’ minds.

The participants’ ability to remember image sequences also depended on the direction of emotional shifts. Remarkably, they remembered sequences better and more coherently when their emotions shifted from neutral to positive. Conversely, a shift from neutral to negative emotions impaired memorization, creating a greater mental distance between different images.

Music as a Tool Against Trauma

While both positive and negative emotions contribute to memories being imprinted, their storage forms vary. These differences become particularly apparent in psychological issues such as post-traumatic stress disorder (PTSD). According to Clewett, traumatic memories that were never carefully and coherently stored, like a box, can make it difficult to control the deliberate retrieval of these memories.

This is why ordinary events, such as fireworks, can trigger flashbacks of traumatic experiences, such as surviving a bombing or gunfire,” the researcher notes. However, there might be a potential solution: “We think we can deploy positive emotions, possibly using music, to help people with PTSD put that original memory in a box and reintegrate it, so that negative emotions don’t spill over into everyday life.”