Difficult tasks require more energy in the brain than simple, automated tasks. They involve more complex cognitive processes and neural networks. The brain is a highly energy-intensive organ, consuming about 20% of the body’s total energy despite only comprising 2% of its mass. The brain is constantly active, even during sleep, and requires a constant supply of glucose and oxygen to function.
When we perform simple, automated tasks, such as typing on a keyboard or walking down the street, our brains can use well-established neural pathways and muscle memories. These tasks require minimal cognitive effort, and our brains can perform them with minimal energy expenditure. It did not happen overnight. The brain learnt through repetition and practice to make tasks simple and automated. One of the goals was to reduce the requirement for energy.
However, when faced with a difficult task, such as solving a complex math problem or learning a new language, our brains must engage in more complex cognitive processes. These tasks require the activation of multiple neural networks and the use of previously unused neural pathways. The brain must also work to suppress distractions and focus attention on the task at hand. These processes require more energy, as the brain works harder to complete the tasks.
Difficult tasks also require more mental effort than simple, automated tasks. For example, when solving a math problem, the brain must engage in problem-solving, reasoning, and decision-making. These cognitive processes require more energy than simply following a set of instructions or performing a routine task.
In addition, difficult tasks often require us to hold multiple pieces of information in our working memory at once. This also takes more energy, as our brain needs to maintain and manipulate this information.
Another factor to consider is that difficult tasks can also generate stress and anxiety, which consume more brain energy. Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, which releases hormones such as cortisol and adrenaline to prepare the body for a fight-or-flight response. This response requires more energy to as the body releases glucose and fats as a source of energy. So if you feel fatigued after doing some strenous thinking, it was because your brain used more energy to do so.fficult