The mind is understood 

This stopping of experience, called cessation of sensation and feeling (saññā vedayita nirodha) indicates, however, that what we call the mind is not another entity separate from the body. It is only an activity of the body, which can be started or stopped at will, just like breathing. Modern scientific research on the brain seems to confirm this fact. 
Mind and body seems to be the same activity viewed from two different angles. When this activity called mind is observed objectively, it is seen as an activity of the body. When this same activity is observed subjectively, it is seen as a mental activity. This makes it clear that what we call the body is an objective experience, while what we call the mind is a subjective experience. The Buddha has pointed out that what we commonly refer to as mind are merely three such activities, which are today known scientifically as activities of the nervous system. They are: perception (viññāṇa), cognition (mano), and affection (citta). Modern scientific findings point out that Perception is the reaction of the senses to stimulation by the environment. Cognition is the activity of the cerebral cortex of the human brain, and affection is the activity of the endocrine system of the body, dependent on the limbic system of the brain. 
There is also evidence to show that there is a part of the brain called the Reticular Activating System (RAS) that can toggle between cognitive activities of mano and the affective activities of citta so that a person can at one time be emotionally activated ignoring the principles of behaviour recognized by the mano, and at another time begin to be calm and composed following good principles of behaviour and good manners. The story of Dr Jekyll and Mr Hyde reminds us of this kind of toggling behaviour. This kind of toggling is also displayed in some people who get drunk by ingesting alcohol. This also happens to all of us sometimes when in a fit of anger or sexual obsession. This is why this introspective awareness is so important in our lives. It can stop this unconscious activity and begin to act consciously and rationally.