Scientists have been looking into this for some time. There are confused because they are looking in the wrong places with the wrong assumptions.
The brain is a processing device. It is an electrical organ works which works similar to a computer with memory. It connect all inputs of various organs and it also controls other organs like the heart. Brain decomposes after death.
You mind is found on every cell of your body. Each cell even behaves as if it has a mind of its own. The brain processes the information generated by these cells. You mind is very creative. It even exists with your soul after death.
Intellect may be defined by many in different ways. The closest meaning to intellect is the capacity to comprehend and evaluate complex issues. I may be wrong on this one.