How the brain suppresses unwanted memories and dampens emotion
Stopping ourselves from thinking about a bad memory directly dampens its emotional sting by using the prefrontal cortex to quiet down memory and emotion centers in parallel.
Source
Parallel Regulation of Memory and Emotion Supports the Suppression of Intrusive Memories
What they did
Researchers tested 24 participants by training them to associate faces with either neutral or highly unpleasant scenes. During functional magnetic resonance imaging, participants viewed the faces and were instructed to either reconstruct the associated image or actively block it from entering their awareness. Two participants were excluded from the analysis due to having too few intrusions during the task.
What they found
Suppressing unpleasant thoughts became easier with practice, and participants who successfully controlled these memory intrusions showed a significant reduction in how negative those scenes felt afterward. Brain imaging revealed that a prefrontal region, the right middle frontal gyrus, acts as a master controller, downregulating activity in both the hippocampus and the amygdala at the same time. This parallel inhibition confirms that the brain does not just block the memory's visual details, but actively suppresses its emotional charge simultaneously.
The limits
What it doesn't show
The study only evaluated neutral and negative scenes, meaning it remains unclear whether suppressing memories would similarly dampen positive emotions. Additionally, because participants did not rate the emotional impact of the images before the experiment, the researchers had to rely on standardized population averages to estimate baseline emotional changes. Lastly, the study relied on participants' subjective, self-reported button presses to track when memories intruded, which cannot be independently verified.
Key terms
- Think/No-Think (TNT) task
- An experimental paradigm where participants are trained on word or picture pairs and then instructed to either retrieve or actively suppress the associated target memory when prompted by its cue.
- Right middle frontal gyrus (MFG)
- A region within the prefrontal cortex involved in executive functions, cognitive control, and the active suppression of memories and emotions.
- Hippocampus
- A seahorse-shaped brain structure in the temporal lobe that is essential for forming, consolidating, and retrieving episodic memories.
- Amygdala
- An almond-shaped structure in the temporal lobe known for its critical role in processing emotional responses, particularly negative ones like fear.
- Dynamic causal modeling (DCM)
- An advanced neuroimaging analysis technique used to estimate the directional influence and causal connections between different brain regions.
- Self-Assessment-Manikin (SAM) scale
- A non-verbal pictorial assessment tool used to measure an individual's self-reported emotional response and valence toward a stimulus.
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Quiz yourself
What cognitive strategy were participants instructed to use during No-Think trials to prevent retrieval of the associated scene?
Common questions
Did suppressing emotional memories make them harder to remember later?
Yes. Even though overall memory recognition was high because of intensive training, participants were significantly slower to recognize scenes they had suppressed compared to baseline scenes, indicating that suppression disrupted memory access.
Does suppressing a memory just block the image, or does it change how you feel about it?
It does both. For people who successfully controlled memory intrusions, suppressing the memory also significantly reduced its negative emotional charge, making the scene feel closer to neutral.
Does the brain suppress the memory first and then the emotion, or both at once?
Causal modeling of brain activity showed that the prefrontal cortex suppresses the memory center (hippocampus) and the emotion center (amygdala) in parallel, rather than suppressing the memory first to block the emotion.
Were unpleasant memories harder to suppress than neutral ones?
No. Participants were just as successful at controlling intrusions of negative memories as they were with neutral ones, suggesting that conscious suppression is highly effective regardless of emotional valence.
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