Humans are not automated machines. Each Human holds a free will that enables him to decide his own unique life. The Human Brain exists as a predetermined working organ of the Human body therefore has no ability to self/determine anything except that which it was designed to do. The organs of the Human body work similar to the parts of an automobile. The automobile cannot freely decide its movements, rather, the automobile depends upon the free will of the driver.
Humans exist as autonomous Beings. Each Human freely, willfully designs his own life. The Human brain does not decide for you that you want the meatball hoagie over the lunch meat hoagie at that moment in time of your desire (maybe the stomach does).
The Human Brain can begin to disease over time no longer working as predesigned. Such catastrophic physical consequences of the Human Brain still does not stop you from desiring love.
Psychological disorders are caused by misapprehensions of the Human free will that cannot be cured by Frankenstein brain treatments.
As a beginning the Human five senses experience the world sending triggers to the Human brain that you are experiencing “something” about the Reality. The Human Brain does not acquire knowledge of language, so cannot define “what is it?” Physical triggers from the Brain now need the Metaphysical Mind to attempt an explanation that my cause the effect towards comprehension via language of “what is going on right now in time.”
There is SO MUCH MORE toward “how does Man come to know anything.” Philosophers and Psychologists have written a magnitude of books seeking answers. Doctors do not write books about “how the brain acquires knowledge!”