Previously, I gave an overview of the mind-body problem and briefly argued that the Materialism cannot explain away consciousness. It is fundamentally a trans-physical creation, or in the words of the well-known neuroscientist Sir John Eccles, "a Divine creation" (Quoted in Varghese, Cosmos, Bios, Theos, pg. 160). However, we are not exempt from considering the role of the brain and body and it's relation to the mind.
The first point I want to make is that the soul is not confined to the brain. Berakhot 10a teaches that just like The Holy One fills the entire world, the Neshama fills the entire body. Furthermore,the Sages (Vayikra Rabbah, 4:5) compare the body to a blind man and the soul to a lame man - only together do they form a functioning organism.
Nevertheless, according to many traditional sources (e.g. Rokeach, Chochmat ha'Nefesh, 34) the locus of focus for the soul is in the brain. The analogy commonly given is that of a radio or television. The sights and sounds are not in the radio or television; it is merely a vehicle for its expression. Similarly, the brain enables the soul to be manifested in this world.
On a deeper level, the brain actually acts as a filter for the powers of the soul. For example, R. Aryeh Kaplan writes (Jewish Meditation, 9-10): “In a meditative state, however, it is possible to turn off the interference and concentrate totally on the rose. As we shall see, with training, one can turn off the spontaneous self-generated images and thus remove the screen. The beauty of the flower when seen in these higher states of awareness is indescribable to someone who has never experienced it. The most I can say is that the rose actually appears to radiate beauty. This can be true of anything else in the world...It is somewhat like trying to tune in to a faint radio station; even if you cannot amplify the volume, you will hear the station more clearly if you can eliminate the static." Also see Berakhot 57b; Niddah 30b; Shiurei Da'at, Chaye Olamot.
Similarly, Aldous Huxley writes: “Reflecting on my experience [with mescaline], I find myself agreeing with the eminent Cambridge philosopher, Dr. C. D. Broad, ‘that we should do well to consider much more seriously than we have hitherto been inclined to do the type of theory which Bergson put forward in connection with memory and sense perception. The suggestion is that the function of the brain and nervous system and sense organs is in the main eliminative and not productive. Each person is at each moment capable of remembering all that has ever happened to him and of perceiving everything that is happening everywhere in the universe. The function of the brain and nervous system is to protect us from being overwhelmed and confused by this mass of largely useless and irrelevant knowledge, by shutting out most of what we should otherwise perceive or remember at any moment, and leaving only that very small and special selection which is likely to be practically useful.’ According to such a theory, each one of us is potentially Mind at Large. But in so far as we are animals, our business is at all costs to survive. To make biological survival possible, Mind at Large has to be funneled through the reducing valve of the brain and nervous system. What comes out at the other end is a measly trickle of the kind of consciousness which will help us to stay alive on the surface of this Particular planet. See here.
Now we briefly turn to different approaches within Judaism to the mind-body problem:
1) The body is crass, physical and made of dust and ashes, while the soul is ethereal, spiritual, and angelic (Orach Chayyim, 6:1, Ramah; Aruch ha'Shulchan, 1:1 ). They come from two different dimensions. However, this is not to say that the soul is completely alien to physical body (although it certainly is not compatible with an impure body). The Kabbalists clearly take the position of Holism - that a soul in its fullness is to be found with a body - in their conception of Techiat ha'Meitim, Resurrection of the Dead.
Avakesh (with a little help from yours truly) writes similarly: “Let us return to the Kabbalistic approach to reality that we have previously discussed. To review, the spiritual rides the physical and the spiritual is both within and beyond the physical. We can posit that Consciousness, a spiritual nonmaterial entity, 'rides' and is enjambed within the physical substance of the brain in such a manner that each can affect the other. In this vein, Sefer Yetsirah (1:7) when discussing how the sefiros function within our world, says: "The beginning is stuck into the end and the end is stuck into the beginning." It is now fashionable in physics to speak about strings - vibrations and waves. One can analogize the physical and the spiritual as being two ends of a wave, so that vibrating either end also vibrates the other. When the brain is stimulated by neural activity (made up of matter), the consciousness (the spiritual) is stimulated. One can stimulate certain parts of the brain and produce a religious experience. However, one can also undergo a religious experience and locate activity in the same location within the brain. One does not disprove the other. It is a two-way street between the spiritual and the physical, top-down and bottom-up.
The assumptions of Cartesians (and all Christian philosophers were pre-cartesian Cartesians) is plain wrong from the Jewish perspective, for they view the spiritual as something distinct and separate from the physical world. However, as we have previously explained, there is no separation between the physical and the spiritual. It is one string and vibrating the string on either end will move the entire string. Activity in both worlds is contemporaneous from the material perspective; in the spiritual perspective which is beyond time, it is co-causative. We can extend this principle to explain why mystical experiences can be mapped within the brain as well as why direct contact with the Divine will cause movement in the brain. They are one organic whole. The whole problem of consciousness vs. neuroscience is only a problem if the two are separated. The Kabbalists, however, teach that they are intricately connected and interwoven.”
2) The body is physical and the soul spiritual but they are twins in all worlds. The body is certainly distinct from the body but it also has a spiritual root, an astral body. R. Yosef Leib Bloch, in Shiurei Da'at (Ki kol ba'shamayim u'va'aretz II), writes:
"Man, at the time that he lives here [in this world] is simultaneously found in the upper worlds. It is incumbent upon us to understand that the way we usually think and imagine [the nature of Man] is incorrect. We usually think that Man is composed of a body and soul, the soul descended from above, was tied to physicality, and after death it leaves the body and rises above. In truth, however, Man is found constantly in all worlds and lives there according to the matters of this world as they are manifested in the upper worlds. Yet the final manifestation of Man is found below in this world, tied and trapped in physicality. This is the part of Man which functions in this lower world through the senses and is limited by the laws of nature of this world. However, the essential existence of Man is found above in the lofty and exalted worlds. There he lives and exists during his descent to this world and even after his death when the body is seperated from him and decomposes.
"However, the relationship between the body and the soul which is found in this world also exists in Man in the upper worlds, although in a completely different sense according to the nature of those worlds.
"Furthermore, all of the aspects of Man that the Sages discerned and labeled as Nefesh, Ruach, Neshama, Chaya, Yechida, are not be understood as separate souls, one above the other, but, rather, according to the truth, there is but one reality that manifests on all worlds. All of these names given to Man are according to his level in each world in which he is found..." Ayin sham v'timsi nachat! Also, see Zohar Vayekel II:197a and Emor III:88b on Eliyahu's light-body.
3) The body, or perhaps only the brain, is the last manifestation of the soul itself. Gerald Schroeder (God According to God, 84-105) writes: "The late George Wald...envisioned that mind is the source of matter. This makes all the sense in the world if, in fact, matter is built from energy and energy is built from information. Suddenly the old conundrum of how the physical brain gives rise to the ethereal mind and experienced sentience evaporates. It is not a question of consciousness arising from matter. It is rather quite the opposite, of matter arising from consciousness."
Later (pg. 226), he continues: "The Bible informs us, and Wald, Heisenberg, Schrödinger, Jeans, and Wheeler have come to confirm, that wisdom...is the substrate, the basis of existence...To quote a portion of Sir James Jean's words...'We are beginning to suspect that we ought rather to hail mind as the creator and governor of the real of matter'...We are truly made...in the tsel’em of God. Tsel'em, the Hebrew word usually translated as "image" contains the Hebrew word Tsel, meaning 'shadow.' A shadow projects the shape of what casts it, yet it has no physical authenticity of its own. That notwithstanding, the presence of a shadow is readily perceived and its effect clearly felt, as we all know, that we seek the comfort of a shadow on hot and sunny days. As Heisenberg, Schrödinger, Jeans, and Wald realized, we are truly the tsel-em, the ethereal projection, of the thought that brought existence into being. Each of us is a spirit clothed with a body."
This approach seems consistent with the Kabbalistic view of the Sin of Adam. The Ramchal (Da’at Tevunot, pgs. 113-114, Friedlander edition), for example, writes that all of existence was on a higher plane prior to Adam’s sin. The body of Adam was on the same level as our soul. With his sin all of reality dropped down into our physical world. The Leshem writes (Derushei Olam ha’Tohu 2:4:3): “Existence has gone from soul to body, from body to garment, and from inner garment to outer garment; it is like a stamp that leaves its imprint on another stamp, which leaves its imprint on another stamp.”
This approach would explain how the soul has senses as well (see Berakhot 10a). Kenneth Ring, in Mindsight, describes the curious phenomenon of people blind from birth that had vision during an Out-of-Body-Experience or Near-Death-Experience. With this in mind, see Tehillim 94:8 and 115; Avot 2:1; Sha'arei Kedusha, 1:1.