Blog #5: The Science of Gratitude

Hi friends!

Happy Thanksgiving (…weekend! lol sorry I’m late -  I had every intent on editing and posting this on Thursday, but then I ate too much and took a 42 hour nap and forgot)! It’s a weird one this year, but I hope wherever you are, you have something to be thankful for today.

Today I want to talk about gratitude. I recently participated in a few mental and emotional wellness discussions/exercises (and, shouldn’t we all! 2020 has been a rough ride haha). One of the most consistent themes that have come up during these exercises is the idea of gratitude. Being thankful for what you have – the people in your life, the roof over your head, the food you eat, the body you’re in. 

I recently read an article that discussed that practicing gratitude has a number of benefits including promoting selflessness, giving you a more positive outlook on life, improving your self-esteem and overall outlook on life! In learning this, I wanted to research more about how gratitude affects the brain specifically – are there measurable differences in brains that tend to be more grateful than others? Are there certain brain regions that have key roles in expressing gratitude? If I start regularly practicing gratitude, can I change my brain? Let’s take a look!

The first study I want to review was published by Sunghyon Kyeong and colleagues in Scientific Reports in 2017, titled Effects of gratitude meditation on neural network functional connectivity and brain-heart coupling. This study looked at effect of the functional connectivity (how well different brain regions activate and rest together) measured by resting-state functional MRI with both gratitude and resentment exercises. These exercises were 5 minute mental training programs consisting of audio and visual messages that were presented to the subjects while inside the MRI scanner. The first minute of the intervention was focused on deep breathing. Then, the next four minutes the participants were encouraged to either (1) focus on the feeling of appreciation for a caretaker (i.e. their mother) for the gratitude intervention or (2) focus on a moment or person that made them angry for the resentment intervention. Participants’ heart rates were also taken during the interventions. The findings showed significantly lower heart rate in the gratitude exercise than in the resentment exercise. Even from personal experience, I’m sure we’ve all felt our heart rates increase when we get angry, especially compared to when we’re feeling positive emotions! For the imaging results, during the gratitude exercise, the strength of the resting state functional connectivity between the amygdala (the emotion processing centers in our brains) and the right dorsal-medial-prefrontal cortex (mPFC, which helps us interpret/reason other people’s emotions) and the dorsal anterior cingulate cortex (ACC, which has roles in cognition, decision making, and emotion) – were positively correlated to anxiety and depression scores. In other words, these pathways that are active during gratitude tasks were weaker in people with less anxiety, a trend that agrees with previous studies that have shown that people with low anxiety have lower functional connectivity between the amygdala and dorsomedial PFC. These pathways have also been implicated in mediating anxiety by other methods, but the findings in the current study suggest that maybe expression of gratitude could be one way to help with anxiety! The study also found significant associations between pathways of cognition and performance during the gratitude exercise, suggesting that gratitude may have potential to improve performance on cognitive tasks!

Next, a study by Glenn R. Fox and colleagues, titled Neural correlates of gratitude, published in Frontiers in Psychology (2015) created first-person narratives based on stories from survivors of the Holocaust, housed in the USC Shoah Foundation Institutes Visual History Archive. In these stories, survivors would often mention situations where they were helped (i.e. given shelter, food, clothes), and felt strong feelings of gratitude. The participants in the study watched prepared documentaries about the Holocaust to immerse themselves in the time period, and then read these adapted first-person narratives in which they were expected to feel gratitude. Though not a perfect model of gratitude, text-based approaches to gratitude (and other emotions, as well!) are commonly used in this kind of research. Twenty-six participants (13M/13F; age range 18-28) underwent functional magnetic resonance imaging with the following paradigm. First, the participant would read a short narrative, such as “A shop owner gives you a place to stay on a cold winter night”, from a screen for ~10s. This will be followed by a “reflection” screen for about 10s before answering the question “How grateful do you feel (with one being “a little” and four being “a lot”)?” Throughout the study, participants were provided different narratives/situations that were expected to give varying degrees of gratitude. After scanning, the participants answered a few more questions, like “How much did you feel each gift was needed?”, “How much effort do you feel the donor had taken to produce the gift?”. They also took personality questionnaires to assess how potential personality differences might affect their perception of gratitude. The results from the imaging study showed that ratings of gratitude correlated with regions of the ventral and dorsal medial-prefrontal cortices (mPFC) and the perigenual anterior cingulate cortex (ACC). Both the medial-prefrontal cortex and the anterior cingulate cortex are implicated in moral cognition, decision making, and reward pathways in the brain. With these results, the authors claim that experiencing gratitude, by evaluating the mental state someone else, immersing yourself in those feelings, and rating that level of gratitude as seen in this study here, we activate the mPFC and the ACC, which further classify and describe how exactly our brain experiences, processes, and expresses gratitude.

Finally, I want to mention this study by Prathik Kini and colleagues, published in Neuroimage in 2015, titled The effects of gratitude expression on neural activity. This study aimed to explore how gratitude is processed in the brain; specifically, looking at how (if at all) regional brain activity correlates with acts of expressing gratitude; whether these brain regions also play a part in functions like empathy and theory of mind processes; how long term gratitude writing habits can affect the brain’s reaction to gratitude. The way this study is set up, a total of 43 subjects were recruited as they were about to begin psychotherapy/counseling. They were divided into two groups – one group (Gratitude) participated in a 60-min gratitude writing intervention in addition to their psychotherapy. The second group (Control/Therapy-as-usual) only participated in psychotherapy alone, and were not asked to participate in the one-hour gratitude writing session. Three months after counseling, the participants underwent fMRI scans, to image brain activation under a gratitude-simulating task. The task, referred to as the “Pay-it-Forward” task, that was organized as follows:
While in the scanner, the participant is shown a screen with a picture of a person who acts as their benefactor, and the amount of money (between $1-$20) the benefactor has gifted to them. The subjects were then shown a potential beneficiary that they could share any amount of that money to. They were told that the benefactor did not want the money back, that they should pass on what they had received to the beneficiary if they felt that they were grateful for the gift, and that the beneficiary was not in immediate need of money, but would appreciate a donation. Then, they were asked a series of questions including how much they would like to donate and if gratitude, guilt, or wiliness/interest in the cause affected their decision. The researchers used the amount of money passed on to the beneficiaries as a way to quantify how grateful the participant felt. Each subject repeated this task 5 times.
Across all subjects in both groups, regions of the medial frontal lobe (decision-making and executive functions), the parietal lobe (sensory/information processing), and the visual cortex (receive and process visual information) all significantly activated during the gratitude task, and the degree of activation agreed with the degree of gratitude motivation. With that, gratitude is pretty much a whole-brain workout! The researchers also found group differences between the Gratitude and Control/Therapy-As-Usual group, particularly in the perigenual ACC, which supports previously published literature (including the Fox (2015) study above!) stating the importance of this region in gratitude experiences. Similar findings were reported in the thalamus, an area of the brain which helps with relaying neural signals across the nervous system and regulates consciousness. And, keep in mind, these images were acquired weeks after the gratitude writing task! So, actually, it’s possible that practicing gratitude creates a lasting effect in our brains, that makes our brains more sensitive to activation when we later experience gratitude, compared to if we had not initially practiced gratitude at all! Your brains networks during gratitude expression is like a muscle, the more you practice it, the stronger it gets! The authors discuss that they did not acquire a pre-intervention MRI, so they cannot say with 100% certainty that there was not some pre-existing preconception to gratitude between the two groups that caused this finding (though, the groups were randomized, which decreases that probability). Also, an important thing to note is that these participants were all seeking help for anxiety and/or depression; the healthy brain may not act in the same way in response to gratitude, and more research would be needed to claim this with confidence. As it seems is always the way in science, there’s still a lot more to learn. But, the initial studies that have been published show great promise for gratitude’s positive influence on the brain!

If you’re interested in learning more about gratitude and the brain, I found two additional pieces that were super informative and helpful. The first is a piece by Linda Roszak Burton, who writes about the Neuroscience of Gratitude, specifically the potential to explore the role of neurotransmitters like dopamine and serotonin (the brain’s feel-good and happy molecules), in gratitude. Another article called The Neuroscience of Gratitude and How It Affects Anxiety and Grief, written by Madhuleena Row Chowdhury, discusses the physical, psychological, and social benefits of gratitude.

So, whether it’s your health, your family, your friends, or peppermint-mocha flavored coffee creamers, please take the time to reflect on something you are grateful for, no just today, but every day. It might do your brain some good!

Thank you for stopping by and reading this post! I’m grateful for you taking the time to do so! I’m also so incredibly grateful for the support I’ve received so far on this blog! I’ll do my best to keep up the work, and your encouragement motivates me to do so! So, again, thank you!

Stay safe, stay smart, stay kind.

Talk to you next time,

-s