I would like to point out that the fact that brain damages or drugs induce changes in our mental capacities simply proves the existence of an interaction between the brain and the psyche.
By no means this can be considered a proof that the brain is the origin of consciousness and the capacity to feel sensations, emotions, thoughts, etc. If you have a problem in your eyes, your visual capacities would be altered, but this certainly does not mean that it is your eye which has the visual sensation; this simply proves that your eye has a preliminary role in the process of generation of the visual sensation.
The eye is only an instrument used by the psyche to see, but the eye can see nothing at all and has no visual sensations.
In the same way, the brain has only a preliminary role in the process of generation of sensations or emotions, and it can be considered an instrument used by the psyche.
All neurological studies on brain only prove the existence of an interaction between psyche and brain. But the existence of this interaction is obvious; in fact, without this interaction, our psyche would be completely isolated from the external reality, and we could not interact with the external reality. It must be stressed that the physical stimulus and the sensation we feel are two completely different phenomena.
For example, the vibrations of the molecules of the air are not the sensation "sound" we feel; the molecules of the air hear nothing, and it would be absurd to say that the molecules of the air are an auditory sensation. The sensation "sound" exist only in the psychical reality, and not in the physical reality; the auditory sensation is generated only by the psyche and is the psychical elaboration of a physical stimulus.
In the same way, the chemical reactions and the electric impulses which occur in our brain are not emotions, feelings, awareness; they are only physical stimuli. It is the our psyche who elaborates and translates these ordinary physical processes into emotions, feelings, etc.