Those “events” could be fleeting, says the study’s lead author, Nikki Puccetti, Ph.D.(c) in the Department of Psychology at the University of Miami. For example, dropping your morning coffee, receiving a testy email from your boss, or getting cut off in traffic are the kind of everyday annoyances that may seem easy to brush off, but when they linger, it can affect how you view other, happier moments, Puccetti says. Over time, this could have an impact on psychological well-being and could even change your brain function to some degree.

Seeing the Negative

In this study, researchers looked at data for 52 people who were enrolled in a larger research effort called Midlife in the United States, aimed at investigating why some people experience better health and well-being during midlife than others. Researchers compared data related to self-evaluation of psychological health, as well as functional fMRI scans taken as participants viewed a series of images—positive, negative, and neutral. Puccetti notes that particular attention was given to the role of the amygdala, a part of the brain associated with emotions, especially fear and anger. Participants whose amygdala was “lit up” for longer while they viewed negative images tended to report lower rates of psychological well-being in general. Those with less amygdala persistence showed the opposite result, reporting a greater positive outlook in terms of daily life and overall—even if they held on to negative reactions for only a few seconds shorter.

Potential Long-Term Effect

Although minor annoyances may be brief, holding on to them may train your brain over time to keep that level of persistence. “These results inform our understanding of more enduring, long-term evaluations of well-being,” says Puccetti. Long-term, you could begin to show signs of what’s called an overactive amygdala, which means having more reactive emotional responses that spike your stress levels. If that happens, it’s possible you may be at risk for chronic stress and the type of health concerns that come with it, including:

Anxiety and depressionSleep disturbance or insomniaHigher risk of metabolic syndromeCardiovascular disease

For those who already have strong fear and anxiety responses, the effect may be even more pronounced. In the recent study, Puccetti says less amygdala persistence predicted more positive thinking and psychological well-being even seven years after the fMRI scans, which means focusing on how you view negative events now may have a very long-lasting effect.

Train Your Brain

Simply telling yourself not to be negative, or to stop holding on to negative thoughts, would be great if it actually worked. But the good news is that just as you’ve unconsciously taught your brain to let thoughts linger, you can help it unlearn that habit, according to Travis Westbrook, Ph.D., a clinical psychologist from Ohio State University Wexner Medical Center who specializes in depression, anxiety, and life transitions. “Mindfulness training is exactly that, a form of training,” he says. “That means much like building a muscle, it takes time for this to get stronger.” This approach focuses on the ability to be fully present, and popular apps like Calm, Headspace, and many others offer a guided practice that emphasizes letting thoughts flow without attachment to them. According to a 2014 study, mindfulness can help reduce focus on negative thoughts by helping you learn to recognize and to control your emotions. Some other options include: Achieving that state, though, can incorporate a range of techniques like:

Meditation Journaling Yoga Mindful eating Active listening Deep breathing Walking outdoors

“Awareness is really the first step in choosing what works for you, and it’s helpful to play around with different strategies to find the right fit,” says Westbrook. “Also, think of this as a lifelong practice, there’s no finish line here. You’re just learning to see your thoughts and emotions and the effect they may be having, and gently steer your mind in another direction.”