The prefrontal cortex is critically important for orchestrating neural circuit activity to achieve focus, attention, task switching, and multitasking.

“if you were to look at somebody and focus on perhaps the expression on their face you could do that while also attending to a conversation that's happening nearby it's energetically demanding it's hard to do but we can do that that's actually referred to as covert attention you're covertly paying attention to something else and then you can switch that attention back to just one thing or one small collection of things the point being that attention is a powerful resource it's what allows us to navigate through life with efficiency and to be adaptive in our behaviors it's what allows us to learn and to build relationships and have successful School careers and professional careers and so on but it is indeed expensive it takes metabolic resources you know just at rest if you were to think about essentially nothing or whatever just pops into your mind with no dedicated effort toward paying attention to anything your brain would consume about 25 of your daily caloric needs and then when you lump on top of that your need or your attempts to focus on things to pay attention to specific things should come as no surprise as to why that often can make us feel tired as if we've been working really hard and we've been running a quote unquote mental marathon when trying to learn and attend to things it's hard work for the brain and yet we can pay attention because of that very precious real estate just behind our foreheads the prefrontal cortex”