The Importance of Idleness for Brain Health

Being idle is one of the most important activities in life.

While our minds are exquisitely evolved for intense action, in order to function normally our brains also need to be idle–a lot of the time, it turns out.

Interestingly, our brain has an autopilot. When we enter a resting state, relinquishing “manual control” over your life, your brain’s autopilot engages. The autopilot knows where you really want to go, and what you really want to do.

For most of our evolution, conserving energy was our number one priority because simply getting enough to eat was a monumental physical challenge. Today, survival does not require much (if any) physical exertion, so we have invented all kinds of futile busyness.

Chronic busyness is bad for your brain, and over the long-term busyness can have serious health consequences. In the short term, busyness destroys creativity, self-knowledge, emotional well-being, your ability to be social–and it can damage your cardiovascular health.

The “resting-state network” (RSN) or “default-mode network” (DMN), as it is called, was discovered by neuroscientist Marcus Raichle of the Washington University in St. Louis in 2001. This network comes alive when we are not doing anything.

This network has a coherent structure in the brain, and there is little variation from person to person. The resting-state network is involved in mind-wandering or daydreaming. The resting network actually becomes active when you are lying in the grass on à sunny afternoon, when you close your eyes, or when you stare out the window at work (if you are lucky enough to have a window at work).

The ability to plan for future states of hunger, cold, or thirst as opposed to just reacting to immediate desires, is perhaps what began the rapid cultural advance of human beings.

We lack genetically specified neuronal structures for reading, and our brains have to recycle other brain structures when we learn to read. Speaking, on the other hand. Evolved much earlier and we normally do not have to struggle to learn how to speak. There are stages to language acquisition that happen whenever a healthy brain develops in a language community, e.g., English, Spanish, or Chinese.

We have specialized brain structures that are attuned to speech perception and speech production. By the time we reach adolescence, we have mastered our native language without any special instructions. However, in contrast, many otherwise healthy people with normally functioning brains reach adulthood not being able to read.

Our bodies were designed for protein-rich diets and long periods of low-intensity physical activity, like walking or jogging, interspersed with idleness. Continually stretching our mental capacity beyond its limits leads to worse job performance, fatigue, and eventually chronic psychological and physical disease.

It is estimated that as much as ninety percent of the brain’s energy is used to support ongoing activity. This means that, regardless of what you are doing, your resting brain represents the vast majority of your brain’s total energy consumption. This is also known as the brain’s intrinsic activity. When you activate your default mode network by doing nothing, it becomes robust and coherent. So, somehow our brains seem to violate the second law of thermodynamics which states that left unattended, things in general get messy and lose heat. This is called entropy. It’s why your kitchen just gets messier and messier the longer you don’t clean it.

The brain represents about two percent of your total body weight, yet it consumes twenty percent of your body’s energy. It is the biological equivalent of the one percent. In other words, your brain is a pig and it is selfish.

We feel obliged to risk our long-term health in order to work extremely hard at jobs we don’t particularly enjoy in order to buy things we don’t particularly want.

Few people fear being overweight as much as they fear terrorism, even though statistically being obese is much more of a threat to your life than terrorism. We do not know how much stress and overwork contribute to shortened life-spans. But we do know that obesity and sitting all day at your desk with a low level of constant stress are related.

There are certain structures in the brain that receive many more connections than other parts. These are the hubs. When you are idle your “brain hubs” light up with activity. More blood carrying oxygen and sugar flow to the hubs in your default mode network when you relax and start daydreaming.

High frequency waves can only travel short distances, but low frequency can travel much farther. Thus, it appears that information coded in higher frequencies “rides” on top of lower frequencies, which can carry the information to distant brain regions.

Source : Autopilot: The Art & Science of Doing Nothing by Andrew Smart

Goodreads : https://www.goodreads.com/book/show/18053732-autopilot