Are the mind and brain one and the same or are mind and brain really separate? Also after reading Wikipedia why are there so many different and somewhat conflicting branches of knowledge like psychology (and it's hundreds of branches), neuroscience, cognitive psychology, cognitive neuroscience, neurochemistry, philosophy of mind (like psychology philosophy also has about a hundred branches) etc studying processes like cognition, perception, thinking, learning, consciousness, memory, volition, emotions, mental imagery etc?
They are indeed the same. Mind can drive and influence the brain while the brain can influence the mind. To say otherwise is to posit an immaterial realm which is non-physical and therefore non-existent. The mind/ brain can generate thoughts and images which one can see with the mind's eye.
Mind is a pattern of action of the brain. It's like asking whether walking is one and the same thing as legs.
In fact, the mind is only ONE function of the brain. The conscious mind is more-or-less resident in the forebrain, the large mass of brain tissue that is several times larger than the corresponding region in the brains of the other species of apes. But many of our memories are stored in the midbrain, which is below the forebrain but above the hindbrain. The forebrain and the midbrain can communicate, after a fashion, and this is how we are able to access old memories. It's also how the new thoughts and experiences we have during the day are organized and stored in the midbrain. This takes place during R.E.M. sleep. The discovery of the technology of controlled fire a couple of million years ago by one of our ancestral species caused a quantum improvement in our brainpower, because campfires kept the predators at bay, allowing us to sleep longer and more restfully--allowing us to organize our memories much more effectively. The domestication of dogs made us even safer at night. We now have two periods of R.E.M. every night, with a total duration of 3-4 hours, and this is what allowed us to develop art, sophisticated stone tools and, ultimately, agriculture, which ushered in the Neolithic Era. The rather small hindbrain, at the base of the head, is the much more primitive mammalian brain that keeps our heart beating at the right speed, regulates body temperature, keeps our breathing steady, has some control over our endocrine system (hormones, etc.), and generally takes care of the part of the brain we share with the most primitive vertebrates: the cartilaginous fishes, which include sharks, rays, eels, etc., animals that have skeletons but they're made of cartilage instead of bone. The brains in the modern vertebrates were actually outgrowths of the olfactory lobe. The cartilaginous fished succeeded because of their sense of smell, which told them where food was, and where larger predatory creatures were. This can be thought of as the first glimmer of intelligence in the first animals with skeletons--our distant ancestors. As you see, the brain has a lot of responsibilities. The mind is only one part of it. In humans, it is a very large part, but in other vertebrates the more instinctive functions in the lower part of the brain play a larger role in their behavior. But even for humans, the brain has a lot of other things to do besides the "thinking" that takes place in the mind. In any case, it is absolutely wrong to say that the mind = the brain. The correct statement is that the mind resides in one part of the brain.
"Mind" is an abstract concept [or future functional scheme fully detailed / exploded] that could potentially be instantiated by other substrates than neural tissue (electronics, alien chemistry, etc). So in that sense the brain is a particular physical member of the category. Distinct from the mind hypernym that subsumes it, yet also very much belonging to it. In our case the brain is the concrete phenomenon and chief region of the body that physically realizes the concept of mind. In practice, biologists adhere to an uncomplicated realism regardless of their personal philosophical preferences. So the "causes" of what is traditionally classed under the mental category are the applicable appearances in the skull (etc) apparent in ordinary perception and instrument-aided detections / measurements. After reason and critical review have examined / concluded such is indeed warranted on the bases of that empirical evidence. The situation like in a computer game or a dream where a character or avatar's brain / body (appearances) would not be the "real" cause of what it did is not applicable in methodological naturalism. Radical skeptical consequences are prevented from falling out of perceptual explanations and scrutiny of our more or less innate realist stances. IOW, the possibility of a transcendent level is excluded a priori or pre-conditionally from any supposed formal system of how science operates. The spatiotemporal components of the natural world have inter-dependency by definition (a circular yet intricately wide maze of the cosmos being causally closed within itself). So the whole point of the science enterprise is to exploit that circumstance so as to explain material phenomena with each other (and the addition of any theoretical agencies whose existence / roles they may indirectly support via experiment / testing).
