All psychological events are represented in some manner by the activity of the brain and nervous system in conjunction with the other body systems one approach to the study of man attempts to relate his actions to events taking place inside his body, particularly within the brain and nervous system.
Recent discoveries have made it dramatically clear that there is an intimate relationship between brain activity and behaviour and experience. Emotional reactions, such as fear and rage have been produced in animals and humans by mild electrical stimulation of specific areas deep in the brain; Electrical stimulation of certain areas in the human brain will produce sensations of pleasure and pain, and even vivid memories of past events.