What causes our brain to get “tired” and lose focus when thinking hard for extended periods of time like studying or thinking through a difficult concept?

Question

What causes our brain to get “tired” and lose focus when thinking hard for extended periods of time like studying or thinking through a difficult concept?

In: 120

Answer 1

The brain has a high caloric demand. Often times when we focus on studying or doing a task, we put off eating or noticing we are hungry. Snack a bit during sessions that require focus and hard thinking.