Sleep

How Sleep and Nature Enhance Your Thinking

Research reveals how two basic interventions can help improve your cognition.

Posted Sep 28, 2020

Mert Kahveci/Unsplash
Source: Mert Kahveci/Unsplash

In the best of times, our choices play a huge role in determining the quality of our lives. When things are less stable, they become even more important. Our decisions influence everything. They affect our health, happiness, finances, and relationships. This is why we need to take steps each day to set up our brains for better choices. Here are two easy ways to make this happen today. 

1. Reset your thinking with sleep.

Have you ever wondered why you’re more likely to eat junk food when you’re tired? Do you find yourself more easily annoyed when you’re sleep deprived? If so, you’ve already seen how sleep can influence our thinking and our choices.

When it comes to brain function, even brief periods of sleep loss matter. After just one night of sleep deprivation, volunteers showed increased activation in the amygdala, an emotional hub of the brain. This helps explain the growing link between a lack of sleep and increased emotional reactivity. In addition, sleep deprivation appears to damage our ability to recognize other people’s emotional states. Combining these findings, it’s easy to see why sleep is so important for our interpersonal connections. And considering that right now many of us are spending much of our time with a very small set of people, sufficient shuteye may actually be essential to preserving relationships. 

In addition to quelling emotional reactivity, sleep can help us to make better choices around foods. A recent review compared the eating habits of people getting a full night’s rest to those who were sleep-deprived. On average, they found that those getting insufficient sleep were eating 385 more calories a day without burning any extra energy. To add insult to injury, insufficient sleep may lead us to preferentially choose unhealthy foods. If we’re trying to lose or even sustain our weight, we need to take this science to heart.

So how do you go about benefiting from all this science? There are plenty of easy ways to get better slumber. For starters, try to limit your blue light consumption in the hours before bed. Blue light can block the production of the hormone melatonin, which is necessary for good sleep. Limit or stop consuming caffeine after 2 p.m., as this chemical can throw off your sleep rhythms. Avoid unnecessary sources of added stress before bed, as they can rev up your brain and make it tough to fall and stay asleep (yes, this may mean cutting the news out of your evening routine). Finally, create and stick to a sleep routine that enables your body and your brain to relax before bed. For example, you could try a hot shower, a mellow read, or listening to calming music.

2. Improve your cognition with nature exposure.

Getting into nature provides a variety of benefits to our bodies and our brains. You’re likely already aware that you feel better after walking around trees, rivers, or oceans. Contact with nature may help protect against heart disease, mental health issues, and early death. We now know that some of these effects may be due to nature’s effects on our brains. More specifically, nature may help us to make better choices.

In 2014, researchers had volunteers look at pictures of nature, urban scenes, or geometric shapes (control condition), and then make a series of choices. The nature photo group made significantly less impulsive decisions. This finding has since been replicated in children. How is this possible? The mechanism appears to involve the stress response.

Chronic stress contributes to everything from diabetes to depression. It’s associated with activation of the brain’s limbic system and especially the amygdala. More practically, it predisposes us to poor choices. People reporting more chronic stress have been shown to make more short-term oriented decisions at the expense of future success. A 2014 review of the subject found “…a strong relationship between stress and impulsive decision making.”

With this in mind, it becomes important to ask whether nature exposure might influence our brain function and subsequently our choices through the stress system. In fact, this hypothesis is supported by the scientific literature. A 2018 meta-analysis showed that exposure to greenery correlated with reductions in multiple markers of stress system activation. These included lower blood pressure, heart rate and cortisol levels. Providing further support for the idea, a 2019 review of brain imaging studies found that urban scenes appear to preferentially activate the amygdala.

The good news is that all this information can be immediately harnessed for the benefit of your cognition and choices. And don’t worry that you lack access to a massive forest or a national park; the benefits of nature can be gleaned from even indoor plants. A 2019 review on the subject concluded that indoor plants were linked to decreased feelings of pressure and anxiety, providing a basis for their anti-stress effects. As described above, even photographs of nature may help. One study showed that images of nature positively influenced recovery from stress compared to urban photos. The bottom line: We can all find a way to incorporate nature into our routine for improved general health, better brain function, and enhanced decision-making.