Sometimes, even when we are wide awake, we fail to pay attention.  Researchers from Stanford found the reason why this is so.  They say that every section of the brain cycles in and out of sleep all day, while you're awake. 

Our Brain Independently Sleeps And Awakens All The Time

This new study recorded the activity of columns of neurons in the brain.  What the researchers found was that each column of the brain's neurons would cycle together, like the ebbing and flowing of a wave.  The brain cycles that happen when awake is the same cycle that happens when asleep.  The research team used extremely sensitive pins that records activity from a column of brain neurons. 

Senior author Kwabena Boahen said: "During an on state the neurons all start firing rapidly.  Then all of a sudden they just switch to a low firing rate. This on and off switching is happening all the time, as if the neurons are flipping a coin to decide if they are going to be on or off." 

The research team also noticed that alert animals and humans tend to have more dilated pupils.  This demonstrates an interaction between synchronous oscillations in the brain, the ability to pay attention to a task, and external signs of alertness.

Why Can't The Brain Stay Active All The Time?

A question arises as to why the brain doesn't stay awake at all times.  Boahen said it could be because of energy.  "There is a metabolic cost associated with neurons firing all the time," he said.  The brain uses a lot of energy, so it could be giving its brain cells some time to recharge.

Also, when neurons are very active, they produce cellular by-products that can damage the cells.  Giving it time to cope would mean allowing it to clear out those neuronal waste.