Chapter 10 Notes Drive Reduction A drive is an aroused state that occurs because of a physiological need You can think of a drive as a psychological itch that requires scratching A need is a deprivation that energizes the drive to eliminate or reduce the deprivation Generally psychologists think of needs as underlying our drives You may have a need for water the drive that accompanies that need is your feeling of being thirsty Th e goal of drive reduction is homeostasis the body s tendency to maintain an equilibrium or a steady state Hundreds of biological states in the body must be maintained within a certain range these include temperature blood sugar level potassium and sodium levels and oxygenation When you dive into an icy swimming pool your body uses energy to maintain its normal temperature When you walk out of an air conditioned room into the heat of a summer day your body releases excess heat by sweating Th ese physiological changes occur automatically to keep your body in an optimal state of functioning Intrinsic motivation is based on internal factors such as organismic needs competence relatedness and autonomy as well as curiosity challenge and fun When we are intrinsically motivated we engage in a behavior because we enjoy it Extrinsic motivation involves external incentives such as rewards and punishments When we are extrinsically motivated we engage in a behavior for some external payoff or to avoid an external punishment According to Maslow s hierarchy of needs our main needs are satisfy ed in this sequence physiological needs safety love and belongingness esteem and selfactualization Maslow gave the most attention to self actualization the motivation to develop to one s full potential Th e lateral hypothalamus is involved in stimulating eating When this area is electrically stimulated in a well fed animal the animal begins to eat If this part of the hypothalamus is destroyed even a starving animal will show no interest in food Th e ventromedial hypothalamus is involved in reducing hunger and restricting eating When this area of an animal s brain is stimulated the animal stops eating When the area is destroyed the animal eats profusely and quickly becomes obese Leptin a protein secreted by fat cells decreases food intake and increases energy expenditure Th e sympathetic nervous system SNS is involved in the body s arousal it is responsible for a rapid reaction to a stressor sometimes referred to as the fi ght or fl ight response Th e SNS immediately causes an increase in blood pressure a faster heart rate more rapid breathing for greater oxygen intake and more effi cient blood fl ow to the brain and major muscle groups All of these changes prepare us for action At the same time the body stops digesting food because it is not necessary for immediate action which could explain why just before an exam students usually are not hungry James Lange theory emotion results from physiological states triggered by stimuli in the environment Emotion occurs after physiological reactions Moreover each emotion from anger to rapture has a distinct set of physiological changes evident in changes in heart rate breathing patterns sweating and other responses Essentially the JamesLange theory proposes that after the initial perception the experience of the emotion results from the perception of one s own physiological changes You see the bull scratching its hoof on the ground and you begin to run away Your aroused body then sends sensory messages to your brain at which point emotion is perceived According to this theory you do not run away because you are afraid rather you are afraid because you are running away In other words you perceive a stimulus in the environment your body responds and you interpret the body s reaction as emotion To understand Cannon s view imagine the bull and the picnic once again Seeing the bull scratching its hoof causes the thalamus of your brain to do two things simultaneously First it stimulates your autonomic nervous system to produce the physiological changes involved in emotion increased heart rate rapid breathing second it sends messages to your cerebral cortex where the experience of emotion is perceived Philip Bard 1934 supported this analysis and so the theory became known as the Cannon Bard theory the proposition that emotion and physiological reactions occur simultaneously In the two factor theory of emotion developed by Stanley Schachter and Jerome Singer 1962 emotion is determined by two factors physiological arousal and cognitive labeling Figure 10 7 Schachter and Singer argued that we look to the external world for an explanation of why we are aroused We interpret external cues and label the emotion For example if you feel good after someone has made a pleasant comment to you you might label the emotion happy If you feel bad after you have done something wrong you may label the feeling guilty To test their theory of emotion Schachter and Singer 1962 injected volunteer participants with epinephrine a drug that produces high arousal After participants received the drug they observed someone else behave in either a euphoric way shooting papers at a wastebasket or an angry way stomping out of the room As predicted the euphoric and angry behavior infl uenced the participants cognitive interpretation of their own arousal When they were with a happy person they rated themselves as happy when they were with an angry person they said they were angry Th is eff ect occurred however only when the participants were not told about the true eff ects of the injection When they were told that the drug would increase their heart rate and make them jittery they said the reason for their own arousal was the drug not the other person s behavior In a typical research study participants when shown photographs like those in Figure 10 9 are usually able to identify six emotions happiness anger sadness surprise disgust and fear According to the facial feedback hypothesis facial expressions can infl uence emotions as well as refl ect them Davis Senghas Ochsner 2009 In this view facial muscles send signals to the brain that help us to recognize the emotion we are experiencing Keillor others 2002 For example we feel happier when we smile and sadder when we frown Support for the facial feedback hypothesis comes from an experiment by Paul Ekman and his colleagues 1983 In this study professional actors moved their facial muscles in very precise ways such as raising their