Hello friends and welcome to a new year, one that we are collectively hoping will be better in many respects. The experience of a pandemic with its attending social restriction has me thinking about how isolation might affect cognition, especially as this virus lingers for months on end. What effect, if any, does loneliness have on the brain?
I didn’t have to look too long to find new research addressing that very question.
This study, published last month in the journal Nature Communications, shows that the brains of lonely people are distinctive in fundamental ways, in both the volume of different brain regions as well as how those regions communicate with one another.
Using magnetic resonance imaging (MRI) data, genetics and psychological self-assessments, researchers looked at approximately 40,000 middle-aged and older adult volunteers who allowed their information to be included in the UK Biobank: an open-access database available to health scientists internationally. They then compared the MRI data of participants who reported often feeling lonely with those who did not.
Differences in the brains of lonely people appeared in the “default mode network”, or DMN, of the brain - a set of brain regions involved in inner thoughts such as reminiscing, future planning, and imagining. The DMN is responsible for how our minds travel when we’re daydreaming about the future or ruminating on the past, stepping away from focusing on the here and now. We spend LOTS of time (almost 50 percent of our waking hours) in the DMN, pandemic or not. Think of all the hours you’ve spent replaying an old conversation in your head.
It may surprise you that while the brain idles in this state, it is remarkably busy! In the absence of social experiences, lonelier people exercise more internal thinking, reflecting, and reminiscing. In turn, the researchers found that lonely people have more strongly-wired connections and increased grey matter volume in the brain regions activated by our inner milieu.
Wait – isn’t it a good thing to grow brain volume and strengthen neural connections? Has the pandemic championed the isolated with the advantage of memory enhancement just by the practice of rumination?
Well, yes and no. Previous studies have shown older people who experience loneliness have a higher risk of cognitive decline and dementia. But understanding how loneliness manifests itself in the brain could be key to preventing neurological disease and developing better treatments.