Your Brain Changes With the Seasons

You vary your clothing with the seasons, pulling out the sweaters and boots in the fall and the sandals in spring. You swap out bedding with the seasons, smoothing a duvet on in the winter and a lighter coverlet in the summer. But did you know your brain also changes with the seasons? A new study published in the journal Proceedings of the National Academy of Sciences suggests that the way our brains operate can switch, based on seasonal changes.

The research was conducted at the University of Liege in Belgium, and while the sample size was small, with only 28 people studied, it still sheds some interesting light on how our brains perform. Researchers looked at the cognitive brain function of participants who spent 4.5 days in a lab during each season of the year. They were purposely placed away from seasonal cues, such as daylight coming in from windows, and any access to the external world. Researchers then scanned their brains while they performed tasks, and looked at the participants’ abilities to pay attention, and to store, update and compare information in their memories.

Their performance on the tasks were consistent throughout the year, but, the neural “cost”—the amount of brain activity involved in performing the tasks—varied with the season. For example, there was higher brain activity involved in sustaining attention in June, near the summer solstice, and less in December, around the winter solstice. Brain activity related to working memory peaked in the autumn, and was lower around the spring equinox.

Previous research has shown that changing seasons are linked to other ways humans function. For example, people tend to consume more calories in the winter months than summer months; activity of our genes changes with the seasons; and immunity fluctuates with the seasons. This new study on cognitive function is yet another example of how our minds and bodies are intimately linked with the natural world around us.