Transcript Emotion
Mind, Brain & Behavior Wednesday March 5, 2003 Emotional States Cahpter 32 Emotion and Motivation Motivation – that which gives energy and direction to behavior. Inferred from goal-directed behavior. Emotion: A process which evaluates the significance of events with respect to important goals. A means of communicating with others. A motive in its own right. Obsolete Theories Concerned with the relationship between experience, emotion and behavior: James-Lange – emotion is epiphenomenal to physiological changes. Cannon-Bard – physiological changes and emotion occur at the same time, emotion can occur independent of physiology. Damasio’s Theory Somatic Marker Hypothesis – emotion guides decision-making as it becomes associated with external events. Primary emotions – innate, preorganized, depend on amygdala. Secondary emotions – acquired associations through experience, analyzed in thought, recruit primary emotions and physiology. Limbic System Includes the cingulate gyrus and hippocampus. Broca (1878): Originally thought to be unrelated to emotion – forms a ring around the brain stem. MacLean (1952) – thought to be the primary circuit for emotion. Papez Circuit (1937) Merging of different streams of feeling, thought, and sensation in limbic areas. Links the hypothalamus with the cortex. Includes the cingulate gyrus, hippocampus, fornix, hypothalamus, and anterior nuclei of thalamus. Emotion Doesn’t Map Well No one-to-one relationship between brain structure and function. Emotion is diverse. Some of the structures in the limbic system are involved in emotion but others are not. Other areas of the brain are important beyond the limbic system. Not a Single System? Basic or discrete emotions – fear, anger, disgust, sadness, joy, surprise. Moods (anxiety, depression, happiness, peace or calm). Preferences and evaluation – negative, positive, like or dislike, approve, reject. Cognitive emotions – curiosity, interest, confusion. Kluver-Bucy Syndrome Kluver-Bucy Syndrome – results from bilateral removal of temporal lobe: Psychic blindness – didn’t recognize objects Oral tendencies – put everything in mouth Hypermetamorphosis – run around and touch everything Altered sexual behavior – x-rated Emotional changes -- fearlessness Importance of Amygdala Some Kluver-Bucy symptoms related to removal of cortex, but most due to removal of amygdala. Amygdala active with fear and anger. Amygdala communicates with hypothalamus and hippocampus. Emotionally important memories and classical conditioning (learning). LeDoux’s research. Kinds of Aggression Predatory aggression – attacks against a different species to obtain food. Few vocalizations Aimed at head and neck of prey Affective aggression – attacks against members of the same species. For show – displays and vocalization Sympathetic ANS arousal. Affective Aggression Competitive aggression – for place in a dominance hierarchy. Defensive aggression – inescapable threat. Irritative aggression – aversive stimulus (paininduced aggression). Territorial aggression – defensive. Maternal aggression – protect young. Sex-related and female social aggression. Testosterone Males are more aggressive than females in most species. Testosterone’s effect appears to be prenatal – unrelated to fluctuations in adult hormones. Testosterone is related to dominance and achievement, task-persistence, successrelated behaviors. Neurotransmitters Lower levels of serotonin were found in more aggressive strains of mice. Animals with less serotonin more likely to attack neutral targets. Depressed humans who commit suicide may have lower levels of serotonin. Children with conduct disorder have less serotonin. Pain and Pleasure Both have an affective component. Sensory pathways involved in pain are complex, involve multiple areas of the brain, and not well understood. Pain and pleasure play a major role in operant learning and classical conditioning. Emotion and Pain Pain is a metaphor for discussing negative affect. Emotion (and especially sympathetic arousal) amplifies the subjective experience of pain. Cognitive activity (distraction of attention) decreases subjective awareness of pain. Placebos can decrease the experience of pain. Pleasure vs. Well-Being Emotion may operate using a homeostatic mechanism with a set point, just as hunger does. Well-being appears unrelated to intense pleasure and unrelated to events in one’s life. Lottery winners vs paraplegics More negative affect than positive. Stress and Anxiety Stress is the response of the body to any demand. Stress is not harmful. Prolonged stress in a situation where one is helpless is harmful (lack of control). Stress contributes to disease. Cortisol is a measure of stress. Stress changes brain chemistry. Social Attachment Emotional expressions generate empathy and regulate interpersonal behavior. Social species have greater emotion. Attachment permits essential learning. Attachment permits individuals to regulate their affect (control emotion). Attachment reduces stress. Emotion Regulation Anger motivates instrumental behavior to change things. However, people must conform to social expectations about expression of anger. Controlling emotion is not psychologically damaging but is what people must learn to do from infancy. Venting is Ineffective Staying angry is harmful. Venting (expressing affect) is ineffective at decreasing or eliminating negative affect – if the person stays angry. Venting prolongs negative affect. Venting does not defuse hostility but escalates it in relationships. Distraction helps. Rumination & Perseveration Perseveration – obsessively returning to thoughts about one’s problems. Ruminating (brooding) prevents active problem solving. Rumination decreases likelihood someone will engage in mood-changing activities. Rumination biases thinking, leading to a vicious circle of depression.