Why your brain actually works better in winter

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6 Ways To Beat The Winter Blues

It was terrifyingly cold in New York this weekend, and this cold snap occurred right as we're entering the postholiday doldrums. It's around the time of the year when people start to talk about seasonal changes to their mood and energy level — most commonly, seasonal affective disorder, or SAD. While SAD is a relatively new condition — it stems from research in the '80s — it has become a huge part of how we in the colder climes discuss winter.

Everyone knows how winter affects certain people: It lowers their mood, makes them more prone to depression, and, in some cases, slows their mind to a crawl. There's a reason for the popular image of someone wanting to just curl up in bed to wait out the duration of a frigid February afternoon.

But scientists are coming to realize that this might not be quite right. A pair of new studies challenge many of the popular assumptions about the psychological effects of wintertime, suggesting that we should look at the season in a new, brighter light. The weather might be gray and chilly, but the latest science says we humans are better at dealing with this than we usually give ourselves credit for, both in terms of our mood and the basic functioning of our brains.

The first study is a massive investigation published recently in Clinical Psychological Science involving 34,294 U.S. adults. It casts doubt on the very notion that depression symptoms are worse in the winter months.

The researchers, led by Professor Steven LoBello at Auburn University at Montgomery, asked their participants to complete a questionnaire about their depression symptoms over the previous two weeks. Crucially, the participants all completed the survey at different times of the year, allowing the researchers to look for any seasonal patterns.

Related: Winter weather around the country so far in February:

February winter weather across U.S.
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Why your brain actually works better in winter
A pedestrian walks through Washington Park as light snow falls on Tuesday, Feb. 16, 2016, in Albany, N.Y. A mix of snow, sleet and freezing rain made driving conditions dicey for commuters across upstate New York, with winter storm warnings and hazardous weather advisories posted throughout the state. (AP Photo/Mike Groll)
Harry Henneman clears snow from the front steps of his daughter's house Thursday, Feb. 18, 2016, in Truckee, Calif. A storm packing rain and high winds downed power lines, toppled trees and delayed flights across California, bringing back winter weather after several days of record-heat. In the Sierra Nevada, the winter storm dropped 1 to 2 feet of light powdery snow late Wednesday, adding to a snowpack that could ease but not end drought conditions when it melts in the spring. (AP Photo/Marcio Jose Sanchez)
One of the 19 stainless steel statues of the Korean War Veterans Memorial is covered with snow in Washington, Monday, Feb. 15, 2016. Bitter cold was replaced by snow, sleet and rain Monday in the mid-Atlantic states and the South, but many residents were able to hunker down at home with federal offices and many businesses closed for Washington's Birthday. (AP Photo/Carolyn Kaster)
A vistor to the Washington Monument walks past flags flying a half-staff in honor of Supreme Court Justice Antonin Scalia on a wintry Presidents Day holiday in Washington, Monday, Feb, 15, 2016. (AP Photo/J. David Ake)
People survey damage to a business off Mississippi Highway 18 in Sylverana, Miss., Monday, Feb. 15, 2016, after severe weather affected south Mississippi. No injuries were reported in the storm. Officials are investigating reports of at least two possible tornadoes that accompanied a line of thunderstorms across central and southern Mississippi Monday. (Ryan Moore/WDAM-TV, via AP)
Frost on a window forms a heart-shaped pattern on Friday, Feb. 12, 2016, in Falmouth, Maine, where the early morning temperature dipped below zero. More cold weather is forecast for the Valentine's Day weekend in New England. (AP Photo/David Sharp)
A bus window is covered by snow and ice, Sunday, Feb. 14, 2016, in Evanston, Ill. Snow has now overspread nearly all of the Chicago Metro area early Sunday afternoon and is expected to continue into the night before ending. (AP Photo/Nam Y. Huh)
People are bundled up as they walk in cold weather, Sunday, Feb. 14, 2016, in the Queens borough of New York. Bitter temperatures and biting winds had much of the northeastern United States bundling up this weekend. (AP Photo/Mark Lennihan)
A bare tree stands in a snowy field near Freeland, Md., Tuesday, Feb. 9, 2016. The mid-Atlantic region awoke Tuesday to a mix of rain and snow. The weather service issued a winter weather advisory in the region and expected the mix to change over to snow and fall occasionally during midday hours, with rain mixing in during the afternoon south of Baltimore. (AP Photo/Patrick Semansky)
Two women run through a snow flurry Tuesday, Feb. 9, 2016, in Nashville, Tenn. (AP Photo/Mark Humphrey)
A passenger waits in the snow to board a bus at Kennedy Plaza in Providence, R.I., Monday, Feb. 8, 2016. Massachusetts, Rhode Island and eastern Connecticut, could see winter storm conditions with an accumulation of 4 to 8 inches. The heaviest snowfall is expected during Monday's morning commute through the afternoon. (AP Photo/Stew Milne)
Kevin Lord, of Sagamore Beach, Mass., braves near hurricane-force winds to inspect storm erosion on Monday, Feb. 8, 2016, along a beach near his home in Bourne, Mass. (AP Photo/William J. Kole)
Jeremy Kincaid clears a sidewalk with a snowblower after a snow storm Friday, Feb. 5, 2016, in Derry, N.H. The storm was New Englandâs biggest snowstorm so far this season, coming two weeks after a massive blizzard engulfed much of the Eastern Seaboard but largely spared Boston and points north. (AP Photo/David Goldman)
Democratic presidential candidate Hillary Clinton departs a campaign stop during a snow storm, Friday, Feb. 5, 2016, in Manchester, N.H. (AP Photo/Matt Rourke)
A snow covered playground is bathed in pink light at sunset before a town hall meeting with Republican presidential candidate Sen. Ted Cruz, R-Texas, at the Lancaster School in Salem, N.H., Friday Feb. 5, 2016. (AP Photo/Jacquelyn Martin)
WASHINGTON, DC - FEBRUARY 13: Ai Koid, 25, fights gusty wind chills and snow while walking to the bus stop at Dupont Circle in Washington, D.C., February 13, 2016, to catch a bus to New York. (Photo by Astrid Riecken For The Washington Post via Getty Images)
Andrew Story clears a sidewalk with a snowblower after a snowstorm Friday, Feb. 5, 2016, in Derry, N.H. The storm was New Englandâs biggest snowstorm so far this season, coming two weeks after a massive blizzard engulfed much of the Eastern Seaboard but largely spared Boston and points north. (AP Photo/David Goldman)
A deicing team prepares a commercial jet for safe flight during severe weather at Denver International Airport, in Colorado, early Tuesday, Feb. 2, 2016. A powerful winter storm has shut down highways in eastern Colorado, closed many schools and slowed down traffic at Denver International Airport. (AP Photo/Brennan Linsley)
Looking southwest from Reno about 20 miles away, clouds obscured the top of Slide Mountain on Monday, Feb. 1, 2016, where the Mount Rose ski resort received 18 inches of snow the day before. (AP Photo/Scott Sonner)
A plow removes snow during severe weather at Denver International Airport, in Colorado, early Tuesday, Feb. 2, 2016. A powerful winter storm has shut down highways in eastern Colorado, closed many schools and slowed down traffic at Denver International Airport. (AP Photo/Brennan Linsley)
Students on the campus of Northern Arizona University navigate through blustery weather in Flagstaff, Ariz., Monday, Feb. 1, 2016. A winter storm dropped snow on the region, closing schools and making travel difficult. (AP Photo/Josh Biggs)

Contrary to what you might think, the results provided no evidence whatsoever that people's depression symptoms tended to be higher in winter — or at any other time of the year. This lack of a seasonal effect was true whether looking at the entire sample or only respondents with depressive symptoms. The respondents' geographical latitude and sunlight exposure on the day of the survey were also unrelated to depression scores.

The researchers are clear about what this means for what they call the "well­-entrenched folk theory" that winter brings on or worsens depression. Their results, they write, "cast serious doubt on major depression with seasonal variation as a legitimate psychiatric disorder." They think the early studies on the concept of SAD were flawed by virtue of the fact that they selectively recruited people who said they suffered from winter-related mood changes — an approach that was likely susceptible to confirmation bias, or selectively interpreting evidence to support a theory you already have. This makes intuitive sense. Once the concept of SAD was introduced, after all, it captured the public imagination and went on to spawn a whole industry based around ways to treat the "condition," including using artificial light.

In spite of the sketchy evidence for SAD, once it was accepted that the dark months affect our mood, it was only a small step to assuming that they probably have an adverse effect on our cognition, too — hence the internet now being full of articles on how to beat that winter sluggishness.

But this idea, too, is challenged by a new piece of research. That paper, published in Proceedings of the National Academy of Sciences, looked at whether the time of year affects basic brain function. It's one of the first studies to do so, and, like the depression-scores study, it seems to refute a common cultural understanding of the effects of cold, dark days.

The neuroscientists, led by Christelle Meyer at the University of Liège in Belgium, recruited 28 young men and women at different times of year to answer questions about their mood, emotions, and alertness; have their melatonin (a hormone that regulates the sleep cycle) levels measured; and complete two psychology tasks in a brain scanner. One task was a test of vigilance and involved pressing a button as fast as possible whenever a stopwatch appeared at random intervals on-screen, and the other was a test of working memory, which involved listening to streams of letters and spotting when the current letter was the same as the one presented three items earlier. The basic idea was to see if the participants' brain activity during these tasks was different depending on the season.

The participants' feelings of alertness, their emotional state, and melatonin levels mostly didn't vary with the seasons, and they actually performed equally well on both tasks in the scanner regardless of the time of year, thus undermining the idea that the winter has an adverse effect on our mental abilities (more on this shortly). One question on mood did show some seasonal variation, but participants' moods were lowest in the fall, not winter. In terms of underlying brain function, participants' neural activity was highest during the memory task for those participants tested in spring and lowest for those tested in the fall, so, far from being a special case, winter brain activity sat in the middle.

Meanwhile, during the vigilance task, brain activity was lowest in the winter and highest in the summer. Some media outlets have interpreted this as evidence for winter sluggishness, but as the participants' performance and alertness was as good in winter as at other times of year, their reduced winter brain activity can actually be seen as a sign of improved efficiency. For comparison, consider research showing how the more expert people become at a task, the less brain activity is seen while they perform that task, as the brain becomes more efficient.

You could even think of this reduced winter neural activity as your brain entering a kind of "eco mode," allowing it to perform as well as it does in summer but while consuming fewer resources. This makes sense from an evolutionary perspective: When resources are scarce and the weather is harsh, it's obviously advantageous that the brain should be capable of performing basic tasks, especially those involving vigilance, in an economic fashion. (I should note that this is my interpretation — the researchers remain relatively neutral about the meaning of the seasonal effects they observed, and didn't return an email I sent them inquiring about what those effects might mean.)

This suggestion that our mental function might actually be enhanced in winter is actually backed up by a (frequently ignored) study published in the late 1990s in Applied Cognitive Psychology. Researchers at the University of Tromsø in Norway tested 62 participants on a range of mental tasks in winter and again in summer (some completed them in winter first, the others in summer, thus balancing out any practice effects). This was just about the perfect setting for such a study, since the contrasts were so extreme: Tromsø is located more than 180 miles north of the Arctic Circle, meaning there is virtually no sunlight in Tromsø during the winter and no darkness in the summer.

Across the battery of tests, the researchers found little evidence of seasonal effects, but those they did find were largely in favor of a winter advantage. In winter, participants performed better on two different tests of reaction time, and they showed evidence of enhanced mental control on the well-established Stroop test that involves naming color words while ignoring the ink color they are written in. Only one test showed a slight summer advantage, and that was for verbal fluency. Summing up their findings, Dr. Tim Brennan and his colleagues wrote that "despite the subjective feeling one may have that one is mentally sluggish in winter, our data do not lend empirical support to the intuitive claim."

Many people dislike winter for obvious reasons, and the idea that these darker months make many of us profoundly miserable and cognitively impaired fits a narrative about this being a difficult time of year (as Adam Gopnik wrote, "one of the most natural metaphors we make is of winter as a time of abandonment and retreat. The oldest metaphors for winter are all metaphors of loss").

But we should be cognizant of how our expectations shape the way we experience the world — it may be the case that, after hearing over and over and over that winter slows us down, making us more sluggish and sad, we interpret days when we're feeling down for other reasons as proof that it's winter's fault.

Sure, the winter presents us with many practical challenges, like coping with colds and flu and getting to work through the snow, but what these new studies suggest is that the season doesn't have some mystical, malevolent effect on our brains. If anything, the data suggest that our minds are more sprightly at this time of year than in the summer. Now there's some news to brighten your day — even if it's an abysmally cold, short one.

Dr. Christian Jarrett (@Psych_Writer), a Science of Us contributing writer, is editor of the British Psychological Society's Research Digest blog. His latest book isGreat Myths of the Brain.

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