Question: what percentage of the brain do we use ?

Joe Bathelt answered on 10 Nov 2016:

There is some misinformation out there that is stating that we only use 10% of our brain. On one hand, that would be great, because we would have lots of capacity to unlock. On the other hand, it would be extremely inefficient. This does not make sense from an evolutionary perspective: the brain is extremely energy hungry and our ancestors would have wasted too many resources to get enough food to feed it if they only got 10% of the capacity from this effort. It’s also not what we find with neuroimaging methods. Pretty much all of the brain is active all of the time. In our studies, we are sometimes interested in areas that are more active than other areas, but that does not mean that the rest is completely switched off.
But note, just because we are using the brain efficiently, does not mean that the brain cannot adapt. The brain can reallocate activity so that tasks can be completed optimally.