As a kid I would start my Christmas countdown in July.
To this day my parents remind me of my elementary school age “post-Christmas meltdowns.” On December 26th they often found me in tears, lamenting the hundreds of days that stood between me and next year’s Christmas.
As the holiday season approached this year I gave my (some would say over-the-top) Christmas adoration a bit more thought. How does just seeing a beautiful wreath or a house twinkling with lights bring me so much joy? With a background in neuroscience research, that contemplation fittingly led me to question how this holiday may be affecting my brain.
Luckily, a few scientists in Denmark were also curious about the brain of a Christmas enthusiast. In 2015 they somewhat cheekily asked where in the human brain the “Christmas spirit network” resides.
They didn’t come up with a plan to study the Christmas spirit network intentionally—they came across the concept during the collection of data for an entirely different study where they were trying to understand the physiological changes associated with migraines. In it they were using functional magnetic resonance imaging (fMRI), a technique used to form hypotheses about brain activity based on changes in blood flow—changes in blood flow are often coupled with neuron firing (i.e. activity).
The healthy control subjects in the migraine study were given image-displaying goggles while they underwent fMRI scans. Some happened to be Christmas-themed. When it came to those images specifically, the researchers were surprised to find that there might be a difference in brain activity between the control subjects.
The researchers initially joked about how funny it would be if they studied the effect of Christmas on the brain. And then they actually did it.
The subjects in the Christmas spirit network study were all healthy adults from the Copenhagen area. Using the previously mentioned goggles, they were shown everyday images, like city streets, and then images that were Christmas-themed, for instance festively-lit storefronts and holiday cookies. Their brains were scanned for activity the entire time.
It was a blind study, which meant the researchers didn’t know how the subjects felt about Christmas before they were tested. It was only after the fMRI scans that the subjects were given a questionnaire where they were asked to describe their feelings toward Christmas. The researchers ultimately analyzed fMRI data from two categories of participants: The first was comprised of those who celebrated and had positive feelings toward Christmas, the second included only those who did not celebrate Christmas and had neutral feelings toward it.
For subjects in the first category, they saw a significant increase in blood flow to multiple regions of the brain. These regions included the sensory motor cortex, premotor and primary motor cortex, and the parietal lobule—areas that are involved in processing sensory input and controlling voluntary movements.
Maybe more relevant to the Christmas spirit network, fluctuations in the activities of these brainstructures have been linked to self-transcendence and spirituality as well as emotional processing and response to the emotions of others.
These findings are somewhat vague and limited to a small sample size of only ten subjects per group (20 in total), but are not without value.
First, this study adds to the growing number of ways that researchers are trying to better understand the brain and how we respond to the world around us.
Next, fMRI is a widely used technique that requires statistical corrections. And the way those corrections should be made seems to be under constant scrutiny and debate.
Questions surrounding the validity of fMRI were prominently featured close to a decade ago in a notorious frozen salmon study in which researchers showed that, without proper statistical corrections used during fMRI, a dead salmon could seemingly elicit brain activity.
Bryan T. Haddock, a medical physicist at the University of Copenhagen in Denmark and one of the Christmas spirit study authors, sees his work as a fun way to tease apart and optimize use of fMRI. “There’s always a difference between a fact and the results of calculation,” he succinctly points out.
In the end, this study wasn’t without its flaws—something the authors were transparent about. And although their findings were nothing awe-inspiring, it’s clear that they had quite a bit of fun. Their entertainment with the subject shines throughout the entirety of the paper, which they close by facetiously stating, “We are currently preparing a patent application on a Santa’s hat that you can buy for family members with symptoms. When they start grumbling at Christmas dinner, with the touch of a button you can give them electric stimulation right in the Christmas spirit centres.”
May you, your friends and family have a scrooge-free holiday season!