Published on March 5th, 20130
Do we get tired if we think too much?
Although the brain is approximately 1/50 of body weight, it consumes about a fifth of inspired oxygen. It is easy to assume that overuse of the brain makes us lethargic and tired, but that’s not quite true.
The brain uses much of its energy to maintain basic state, while a tenth of our energy is consumed for pumping sodium and potassium ions across the cell membrane brain, a process that maintains each neuron loaded and prepared. Instead, specific mental activity (solving a puzzle) does not require a lot of extra energy.
Over time, studies have shown that after demanding mental tasks, people become more poor. One such experiments coordinated by Samuele Marcora at the University of Kent, to divide subjects into two groups. Members of the first group were subjected to computer game quite exhausting, while the remaining subjects watched a documentary about sports cars. Subsequently, all participants were tested for endurance on a bike. Thus, Marcora found that people who were “mentally exhausted” gave up riding faster than those who chased the documentary.
Meanwhile, Marcora found no link between mental load and cardiovascular response would participants, blood pressure and oxygen consumption. In other words, the effort has not slowed mental bodies, but, but instead made the subjects to perceive physics as a difficult task. So it seems that mental effort tires us, but everything is in our heads.