Modern scientific research
Modern research on the brain has indicated that this process called experience is the activity of a part of the brain called the cerebral cortex that does the thinking. The brain of course is a part of the body. Therefore it is the body that does the thinking and not the mind. The term “mind” refers only to three activities of the body: thinking, feeling and perception. Thinking and feeling are technically called cognition and affection. The Buddha had three terms for these activities: perception (viññāṇa), cognition (mano) and affection (citta).
It is with cognition (mano) that we make meaning out of what we perceive. Perception is only the reaction of the organism to stimulation by the environment. We are organisms in an environment. We have five senses that can be stimulated by the environment. The organism reacts to this stimulus and so perception takes place. What is perceived is brought to the brain by nerves and the cerebral cortex gives meaning to what is perceived. This giving meaning to what is perceived is called cognition. According to the meaning given by cognition an emotion is aroused. This arousal of emotion is called affection. The emotion aroused is expressed in action. This action is called karma (in Sanskrit), or kamma (in Pali). The action may be to obtain what we desire, to get rid of what we hate, or run away from what we fear.
This arousal of emotion is what is called stress today. Stress is a disturbance of the body and mind, if continued too long it can be damaging not only to the body and mind but also to others around and society in general. All crimes in the world, all wars, murders, and every problematic human disturbance is a result of emotions. These emotions are blind and unconsciously carried out but dependent on the necessary conditions.