Chances are, you know firsthand how your mood changes with the seasons—there’s a reason why the terms “winter blahs,” “cabin fever,” and even “seasonal affective disorder” are used with such frequency during the colder months. But emerging science suggests that the seasons can also affect the way your brain works.

A small study in Belgium found that your brain’s response to certain cognitive tasks changes in different seasons. In the study, the participants were sequestered in a lab—without seasonal cues—for 4½ days four separate times throughout the year. In each session, the participants were deprived of sleep and then allowed to recover, at which point researchers measured the participants’ brain function as they performed two different tasks: one requiring sustained attention, and one requiring them to use their working memory (aka how we keep track of short-term information we’ve learned until we need to use it).

While their test scores were stable throughout the seasons, the researchers found that the “cost” of cognition (or the neural resources the participants had available) changed depending on the time of year. Turns out, we have less brain activity around cognitive tasks like attention in the winter versus in the summer, and more brain activity around memory in the autumn than in the spring.

The scientists couldn’t say exactly why our brains work differently in different seasons, but suggested that more basic tasks, like attention, could be related to environmental changes, like day length, while more complicated tasks could be tied to more complex causes, like social interactions. Obviously, more research needs to be done.

Mood and cognitive function aren’t the only things scientists have linked to the seasons. Studies show that our metabolism slows down in the winter (yes, you are sort of hibernating!). And a study found that our immune systems may respond differently to the seasons, while another small study found that we may see colors differently throughout the year.

The Belgian study doesn’t mean we pay more attention in the summer or we’re less forgetful in the fall, but it does shed a bit more light on how our brains work—and it could eventually help scientists better understand conditions like seasonal affective disorder. We’ll raise a hot cocoa to that!

Get more great health and wellness stories at