Study on ‘bah humbug syndrome’ offers cautionary tale

Feeling a bit “bah, humbug” about Christmas?

Maybe your brain is to blame. 

For, according to a team of jolly old Danish researchers, people who get into the “Christmas spirit” exhibit different brain patterns in response to holiday images than those who don’t.

“Throughout the world, we estimate that millions of people are prone to displaying Christmas spirit deficiencies after many years of celebrating Christmas,” write the researchers. “We refer to this as the ‘bah humbug’ syndrome. Accurate localization of the Christmas spirit is a paramount first step in being able to help this group of patients.”

OK, OK. Before I go any further with my summary of their research, I need to explain up front that this is yet another of those “odd and quirky” studies that appear each year in the Christmas issue of the BMJ (formerly called The British Medical Journal) — studies that follow “real” scientific methods and that are even peer-reviewed, but that are definitely conducted with tongue planted firmly in cheek.

Yet, in addition to having some fun, the authors of this particular study seem to want to tell a cautionary tale: Using brain activity maps and measurements to draw conclusions about what people are thinking or feeling can lead to conclusions that are, well, kind of silly.

‘No eggnog or gingerbread’

For the study, the researchers recruited 20 Danish volunteers. Half (eight men, two women) were celebrators of Christmas. The others (again, eight men and two women) were not.  The volunteers underwent functional magnetic resonance imaging (fMRI) of their brains while watching a series of 84 images through video goggles.  Some of the images evoked Christmas — a night street scene lit up with holiday lights, for example, or a plate of food set on a table with Christmas decor. Others did not. 

To make sure the study was free of any kind of sensory bias, “no eggnog or gingerbread was consumed prior to scanning,” according to the researchers.

Although both groups of volunteers showed similar flows of blood through their brains (“despite the Christmas group’s yearly yuletide feast”), further analysis of the scans revealed definite differences. When viewing the Christmas-y images, the people in the study who said they celebrated the holiday demonstrated higher blood-flow activity in several specific brain areas, including the parietal lobules, the premotor cortex and the somatosensory cortex. 

The parietal lobules, the researchers point out, have been linked in earlier fMRI studies to “self-transcendence, the personality trait regarding predisposition to spirituality.”

And the frontal premotor cortex has been identified as an area of the brain where people share emotions with others by mirroring their movements.

“Collectively,” the researchers conclude, “these cortical areas possibly constitute the neuronal correlate of the Christmas spirit in the human brain.”

Or not.

For, “although merry and intriguing, these findings should be interpreted with caution,” write the researchers, adding (in an accompanying press release) that “something as magical and complex as the Christmas spirit cannot be fully explained by, or limited to, the mapped brain activity alone.”

‘Neuro-bollocks’?

And here’s where the researchers present (with good cheer — and British spellings) their cautionary message about this type of research:

We realize that some of our colleagues within the specialties of neuroscience and psychology, who we suspect could be afflicted by the aforementioned bah humbug syndrome, would argue that studies such as the present one overemphasise the importance of localised brain activity and that attempts to localise complex emotions in the brain contribute little to the understanding of these emotions. Citing a paper reporting fMRI evidence of brain activity in frozen salmon,  representatives of this view have even coined terms for this practice such as “blobology,” “neo-phrenology,” “neuro-essentialism,” and “neuro-bollocks” (Grinch and colleagues, personal communication).

Naturally, in keeping with the good spirit of the holiday, we disagree with these negative perspectives.

We generally believe that fMRI is an outstanding technology for exploring the brain but that any fMRI experiment is only as good as its hypothesis, design, and interpretation. While celebrating the current results at a subsequent Christmas party, we discussed some limitations of the study. For instance, the study design doesn’t distinguish whether the observed activation is Christmas specific or the result of any combination of joyful, festive, or nostalgic emotions in general. The paired Christmas/non-Christmas pictures might have been systematically different in a way that we were not aware of — for example, the “Christmas pictures” containing more red colour. Maybe the groups were different in other ways apart from the obvious cultural difference. Given these uncertainties and the risk of false positive results, our findings should ideally be reproduced before firm conclusions are drawn, especially when we consider the recently documented challenges of reproducibility in our neighbouring specialty of psychology. [Ouch.]

Bringing these issues up, however, really dampened the festive mood. Therefore we, in the best interest of the readers of course, decided not to ruin the good Christmas cheer for everyone by letting this influence our interpretation of the study.

You can read the study in full (maybe while sipping a glass of eggnog?) at the BMJ website.

Oh, and in case you’re wondering, the authors of the study state that they are totally free of any conflicts of interest in regard to this research, although, they add, “we would like to call ‘dibs’ on any profitable non-invasive or even invasive treatment of bah humbug syndrome. 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.”

Ho, ho, ho.