Do you ever find it difficult to pay attention during a long meeting?
We all do. But why do we feel that way?
The reason is that fatigue impacts our brain’s physiology.
So, what happens in our brain when we feel fatigued?
Up until now, we thought that the feeling of fatigue was generated when it was time to rest and recuperate. These days, the reasons for that feeling are becoming clearer.
The lymphatic system cleans waste products from our body, but our brain is too dense for that. We thought the wastes produced by the brain were dealt with by diffusion processes.
A New Waste Cleaning System Discovered
Research discovered a new waste cleaning system on mice brains (which are remarkably similar to human brains). This new “glymphatic system” uses cerebrospinal fluid (or CSF, the fluid that surrounds our brain) to flush away wastes.
This new system is a once-off process that pushes large volumes of CSF past all parts of the brain to carry away wastes quickly and completely. Because the brain is always so busy when awake, we activate it during sleep and could explain the “waking up refreshed” feeling we get after a good night’s sleep.
It appears that the feeling of fatigue is the result of waste product "build up" in our brain impeding normal electrochemical activity. Although it is still early days, this research provides a useful perspective for explaining the “brain fog” feeling we get when we think hard or pay attention for sustained periods.
When diffusion cannot deal with this "build-up" quickly enough, neural impairment results and we begin to feel fatigued.
The afternoon nap (popular in Latin countries) or the power nap allows diffusion to catch up before sleep comes around.
Unfortunately, fatigue is unavoidable. Sooner or later we all need sleep. Droopy eyes, long blinks and slower reflexes are easy to recognise in others but not so easy to recognise as it is happening to us.
However, that does not mean we can’t manage fatigue better.
Next Time: Fatigue - Why is it difficult to manage?