The part of the soul that has memories, intelligence and life is the human spirit, the breath of life, Job 32:8 , also called the spirit of man, 1 Corinthians 2:11 , Proverbs 20:27 matter cannot be intelligent, have memories or be the source of life. The human brain is like an interface between your body and human spirit. If you are dead you cannot do anything, your thoughts perish, the dead know nothing. The body without the spirit is dead, James 2:26 Psalm 146:4 In the first resurrection we will have bodies composed of 100% spirit and our transformed human spirit that is sealed in GODS righteousness and love is joined with this new spirit body and the old physical fleshly brain is dust.