MIAMI, Fla. — It turns out the song “Don’t Worry, Be Happy” may be more accurate than people think. Psychologists at the University of Miami say the longer negative emotions linger in the human brain, the worse it is for your mental health.
Suppose you drop your breakfast on the way to work and it splatters all over your clothes. Later that day, a colleague comes up to say hello, not knowing about your rough morning. Do you grumble a reply, still thinking about your lousy day, or greet them politely?
The study finds those holding on to negativity longer in their amygdala may impact their long-term psychological well-being. The amygdala is the almond-shaped structure on both sides of the brain’s cerebrum which evaluates stimuli and supports emotion and memory.
“One way to think about it is the longer your brain holds on to a negative event, or stimuli, the unhappier you report being,” says lead author and Ph.D. candidate Nikki Puccetti in a university release. “Basically, we found that the persistence of a person’s brain in holding on to a negative stimulus is what predicts more negative and less positive daily emotional experiences. That in turn predicts how well they think they’re doing in their life.”
“The majority of human neuroscience research looks at how intensely the brain reacts to negative stimuli, not how long the brain holds on to a stimulus,” adds assistant professor of psychology Aaron Heller. “We looked at the spillover—how the emotional coloring of an event spills over to other things that happen. Understanding the biological mechanisms of that is critically important to understanding the differences in brain function, daily emotions, and well-being.”
Holding a grudge can affect your well-being?
Researchers examined how different reactions to emotional pictures and experiences on a daily basis can affect well-being over time. They theorized that the amygdala plays a key role in this process.
Puccetti and Heller analyzed data on 52 participants from the Midlife in the United States (MIDUS) study. This group completed a questionnaire about their psychological well-being and reported stressful events and positive or negative emotions they experienced in a nightly phone call for a week. Participants also underwent functional magnetic resonance imaging (fMRI) scans to measure brain activity while viewing dozens of images.
Researchers asked the group to rate these 60 positive and 60 negative images, spread out by 60 images of neutral facial reactions. The results of all these tests show that people whose left amygdala holds on to negative stimuli for fewer seconds report more positive emotions in their daily lives. This also spills over into these volunteers displaying a healthier well-being later on. On the other hand, people reacting more persistently to negative images experienced more negative emotions on a daily basis.
“It may be that for individuals with greater amygdala persistence, negative moments may become amplified or prolonged by imbuing unrelated moments that follow with a negative appraisal,” study authors suggest. “This brain-behavior link between left amygdala persistence and daily affect can inform our understanding of more enduring, long-term evaluations of well-being.”
Explaining the triggers for mental health problems
Puccetti believes this link may explain why some people can simply “let it go” when bad things happen to them. For those you can’t, the team hopes to repeat the study with participants who are at high risk for developing depression or anxiety.
“It might be the case that they’re showing even greater persistence and that’s something that can tell us about why they might be more likely to go on to develop a psychiatric disorder,” Puccetti concludes.
The study appears in The Journal of Neuroscience.