In this chapter you will learn
 

• Some of the ways psychologists have viewed motivation
• How the concepts of drive and homeostasis explain the regulation of internal body states
• How taste helps us select a safe and nutritious diet
• How we regulate the amount of food we eat
• What some of the causes of obesity are
• What we know about anorexia and bulimia

Chapter 6 reviews how internal states such as temperature, energy, and water balance are maintained. When one or more significant conditions are out of balance, the nervous system triggers behavioral systems to correct the imbalance. Motivation involves a set of factors that orchestrate behaviors to maintain or correct the internal states. The chapter begins with the physiological bases of motivation and homeostasis, illustrated by the simple homeostatic drives of temperature regulation and thirst. Hunger, a much more complex drive, is then described, along with the role of taste and the various processes involved in digestion. Finally, eating disorders are reviewed. The various contributors to obesity are discussed, as well as anorexia and bulimia nervosa. Neurotransmitters and their influence in the eating disorders are given particular attention.