Everything upon earth ultimately uses a physical pathway because that is how all manifestation takes place here. The hub of these pathways is the brain and the nervous system. The mistake that one makes is to believe that it is the brain and its connections that creates our cognate experiences. This has been refuted by a number of experiments. The placebo and nocebo effects are elementary facts that point towards our mental conditioning and belief overriding the actual physical effect. That is in fact the basis of treating phobias, a kind of deconditioning, where there is no brain damage and yet one gets rid of fear by training the brain through the mind and will.
Similarly, there are descriptions of personality change following head injuries. What this refers to is that certain outer behavioral changes are consequent to the damage. Equally changes in outer behaviors can be programmed through learning and unlearning. What has to be understood here is that much of these observations, fear of certain elements, changes in behavior etc. are taking place in the outermost personality of a person. Most of us regard this outermost personality as the person himself. Yogic experience however affirms that there is behind this outer plan an inner personality, an inner being and even an inmost being which can change the fixed determinism of nature, even override its processes and even change it.
What it means is that right now to our surface view, everything seems to be an interconnected play of mechanical determinism solely dependent upon physical processes. In this view we do not need a driver or an owner and builder of the bodily machine. It is somewhat like knowing all about a car with all its interconnected mechanisms which can perfectly explain a car and its functioning except these three relevant things such as the driver which is the will and faith in man and the discerning intelligence which decides which way we go, the owner to whom it temporarily belongs, the soul so to say, and the inventor or the Divine Consciousness who has the knowledge to build new cars and to modify this one.
To get back to the change of personality we can therefore say that the changes we observe in the outer personality, ways of behavior and speech and responses such as fear or joy to outer events are inbuilt mechanisms within the brain substance due to heredity and conditioning. They get altered when the brain mechanism gets damaged. But the inner aspects of personality such as the true will in us as opposed to surface desire and the fundamental faith as opposed to belief (of which few are really even conscious as most live on the surfaces driven by outer forces) remain largely unaltered. The core of course invariably remains intact and often it emerges more powerfully because sometimes the injury removes the outer hindrances such as the phobia mentioned in this case. Once the outer conditioning is gone these deeper possibilities have a chance to emerge. Head injuries and certain brain disorders actually remove the cap that limits the range of our expression and behavior releasing from within us the titans and the gods. The same thing happens through yoga of which yogis are well aware.
