In a moment of fear, the flight or fight response is instinctual. A small cluster of cells buried deep in the brain called the amygdala is known to be responsible for this basic response. Beyond this, the amygdala is involved more broadly in the processing of memory and emotional reactions.
A group of scientists at the Center for Investigating Healthy Minds at the University of Wisconsin-Madison Waisman Center are studying the amygdala response using functional MRI (fMRI). The findings suggest that the duration of response, rather than the intensity may provide key insight into personality traits like neuroticism.
“What we found is that overall the time course matters,” said Tammi Kral, research specialist and member of the research team involved in the study. “What we found is that the amount of activity people have during the post-stimulus period or recovery period is related to their level of self-reported neuroticism.”
These findings come from the baseline portion of a much larger study looking at mindfulness-based stress reduction. Study participants underwent a 24-hour visit, which included a sleep study and the fMRI. In the fMRI portion of the study, participants were shown batches of images and asked to rank these images as positive, negative or neutral while in the MRI scan. Researchers then analyzed the activity in the amygdala, and the duration of the activity in a recovery period.
Neuroticism is defined to include a tendency to worry excessively and trouble letting go of negative emotions. In this study, neuroticism was self-reported by participants through a questionnaire. The finding that a longer duration of activity in the amygdala is related to neuroticism could have important implications in the study of behavior.
“It will be really important going forward to look at not only how people react overall to a stimulus, which is currently kind of the standard in brain imaging, but also to look at how that response changes over time,” Kral said.
The larger study will use a combination of fMRI, sleep data and epigenetics to examine how mindfulness-based stress reduction can improve response to negative stimuli. The epigenetics portion of the study will look at how gene expression and silencing changes with lifestyle change.
“The goal of the larger study is to look at this mindfulness-based stress reduction intervention and see if it leads to any changes in a number of measures including emotion regulation, sleep patterns, dealing with pain, stress response,” Kral said.
This study will include several groups of participants. One group will participate in an eight-week course in compassion meditation, while another will serve as an active control that receives identical training as the first without the mindfulness aspect. Another group will not undergo any training, and a final group is comprised of long-term meditators. By comparing any changes that these cohorts may undergo over the course of the study, the researchers hope to parse out the potential benefits of mindfulness.
“We are hoping to measure effects of short term training in mindfulness-based stress reduction as well as long-term training in mindfulness-based meditation,” Kral said.
It has long been known that exercise can improve health and aide in managing stress. If this study finds benefits associated with mindfulness-based stress response, meditation could also come highly recommended to help relieve stress and let go of negative experiences.