You've probably noticed the air getting chillier every day, the leaves crisper, and the trees emptier. From the contrasting mix of the leaves’ beautiful warm tones to the crunch of them as you walk on the greying grass, to the strong wind blowing them away, and to the smell of earth mixed with a whiff of the local coffee shop's pumpkin spice latte - autumn brings a lot of change for us to explore. 

As we get further into the fall season, take out our coats, boots, and sweaters, the external changes we go through affect us both physically and mentally. Studies even suggest that this season has unique benefits for the brain. Do we naturally concentrate and think better in the fall? And is there a mechanism behind this?

Autumn and the Brain

Research suggests that seasonal changes in the expression of certain neuroplasticity genes mediate our ability to think and learn. A 2018 study by researchers based at the University of Toronto and Sunnybrook Health Sciences Centre found that in the late summer and early fall, older adults with and without dementia had better cognition than in the winter and spring. They tested 3,353 older adults in the United States, Canada, and France and showed a significant association between season and cognitive function, with the difference being that in the early fall, the brain function of those studied was 4.8 years younger than in winter, and spring. The same study also found seasonal variations in protein levels linked to Alzheimer's disease, suggesting that some cognitive function may be regained in the fall for Alzheimer's patients. This most probably has to do with more than just the season itself, but with everything it brings - changes in temperature, day length, sleeping habits, diet, hormones, and more. For instance, researchers are actively studying the effects of sleep disturbances on the brain, particularly for Alzheimer's disease patients. Studies have also shown that melatonin levels controlling our sleep increase as we get closer to winter and as we are exposed to less sunlight on average. 

Interestingly, a common phenomenon known as the "October sleep slump" results from the sleep changes we experience with the change in weather and environment. Some tips for avoiding the slump at this time include sticking to a consistent bedtime, winding down without devices an hour before bed, and ensuring you get as much sunlight as you can within the first hour of waking. You can also check your vitamin D levels consistently and ensure you're getting enough of it, as it has been shown to affect more than just bone structure. Vitamin D deficiencies are associated with mood changes, depression, and fatigue.

What if there were no seasons?

Some countries have fewer contrasting seasons throughout the year, which can affect the brain's function and adaptability. A study published in the PNAS journal investigated the effect of having no indication of the season outside on young participants in their early twenties. For 4 and a half days at a time over the course of a year, they were not exposed to nature. Using functional magnetic resonance (fMRI) imaging, researchers were then able to point out significant patterns in participants' ability to remember in the short term and pay attention. 

For tasks requiring attention, brain responses were at their highest in the summer and lowest in winter. For tasks requiring working memory, brain responses were at their highest in autumn and lowest in spring. However, the ability of participants to perform the tasks remained stable throughout the seasons. This suggests that brain activity varies from season to season as the brain adapts to different environmental cues, but this does not appear to affect its fundamental ability to perform tasks. The brain remains accurate and capable as it adapts to its surroundings. This is not a new idea, as the brain's neuroplasticity is one of its unique features. It's able to form new connections and pathways, adjust them, and remember them in different ways to ensure optimal functioning. So while it may be easy for us to blame the change in seasons for our cognitive mishaps here and there, the seasons may actually have little to do with it!

Mindset