Three Minute Review: Motivation 1 what drives people to behave the way they do? regulatory drives non-regulatory drives hypothalamus Hunger homeostasis thermostat analogy tiny area, important functions, links with limbic system, 4F s hunger centre (LH) vs. satiation centre (VMH) how does the body maintain the correct level of food intake? interplay between VMH and LH obesity twin studies and adoption studies can be useful in nature vs. nurture questions genetic factors play a large role in weight gain and weight distribution thrifty gene in a Supersize culture? set point theory changes to food intake may shift the set point making it harder to change your weight anorexia nervosa bulimia nervosa have our cultural ideals become unreasonable? Which of the following could cause a rat to eat (true/false)? What determines sex drive? Hormones androgens estrogens (From the lecture) Cultural influences and situations more important to women Genetics Is there a gay gene? Sex Differences in Sex Drive Women status, money, age, and concern for children Men Evolutionary theory feeling full blood glucose levels fat cells secrete leptin Test Yourself Sex eating disorders see also more detailed explanations, Gray Ch. 6, FQ10 electrical stimulation to the ventromedial hypothalamus a lesion (damage) to the ventromedial thalamus electrical stimulation to the lateral hypothalamus a lesion to the lateral hypothalamus a decrease in blood glucose below the set point a decrease in body fat below the set point (From the book) beauty, youth and sex women: find a solid guy with good resources who ll stick around men: sow your seeds far and wide Pleasure centre General motivational drive? Dopamine is key neurotransmitter an injection of leptin an injection of insulin a water-filled balloon in the stomach the presence of especially tasty rat chow even if the rat isn t particularly hungry bell-ringing for a rat with a bell-food association (Pavlov s rat?) Many addictive drugs stimulate dopamine Why have emotions? What is this man from New Guinea feeling -anger, happiness, disgust, sadness? 1. Video: Cavanagh: Disk 3 Emotion Expression (2:10) Emotions communicate 2. Dimensions of Emotion consistent across cultures and even species Emotions aid in decision-making gut feelings often right people with damage to the emotional system (orbitofrontal cortex) are poor at using past outcomes to regulate future behavior in a gambling task 3. Emotions capture attention and aid memory 4. Emotions strengthen interpersonal relations guilt, embarrassment, jealousy 1
Autonomic Nervous System Arousal Imagine you re writing an exam of average difficulty. How well would you do if you were really mellow or drowsy average really stressed (or hooped on chocolate-covered espresso beans)? QUALITY OF PERFORMANCE Low Medium High Fig. 5.4 LEVEL OF AROUSAL Arousal How much coffee would you want to drink if you were: driving? writing an exam? giving an important talk for the first time? Rats could avoid shock by going into brighter of two compartments Experimenters varied the strength of the shocks given to the rat and measured their accuracy at picking the brighter compartment. Yerkes & Dodson (1908) Yerkes-Dodson Curve 1. Common Sense Theory Yerkes & Dodson (1908) rats did best if: the task was easy and they were highly aroused (by strong shocks) the task was moderately difficult and they were moderately aroused (by moderate shocks) the task was difficult and they were weakly aroused (by weak shocks) 2
2. James-Lange Facial Feedback Theory we feel sorry because we cry, angry because we strike, afraid because we tremble, and not that we cry, strike or tremble because we are sorry, angry or fearful. -- William James Smiling makes you feel happier 3. Cannon-Bard Theory Schachter s Experiment Schachter & Singer (1962) subjects were injected with adrenaline (or a placebo) adrenaline sweaty palms, increased heart rate, shakes some subjects were told they would feel aroused; some were told nothing left subjects in a waiting room with a confederate euphoria condition confederate played with a hula hoop and made paper airplanes angry condition Stanley Schachter 1922-1997 Schachter s Results confederate asked obnoxious personal questions (e.g., With how many men other than your father has your mother had extramarital relations: (a) <5; (b) 5-9; (c) >9 4. Schachter s Attribution Theory Cognitive appraisal = TYPE of Emotion Degree of Arousal = INTENSITY of Emotion This figure is simpler than Fig. 6.24 (which you can ignore) in your text 3
Misattribution of Emotion Which woman is more attractive? emotions can be attributed to the wrong source (Dutton & Aron, 1974) male subjects were asked to meet the experimenter on a bridge across the Capilano River in B.C. Group 1: Capilano suspension bridge Group 2: sturdy modern bridge attractive female research assistant interviewed them in the middle of the bridge and gave her phone number Men interviewed on the scary bridge were more likely to call her An idea for your next date? Emotion in the Brain The Amygdala part of the limbic system (with the hippocampus and hypothalamus) amygdala = almond processes emotional significance of stimuli and generates immediate reactions damage to amygdala inability to recognize facial emotions absence of fear absence of conditioned fear response abnormal activation of amygdala sudden violent rage in fmri studies, the amygdala is activated by scary stimuli (even if you re not aware of them) Phineas Gage Frontal Lobes Gage is no longer Gage 4
Frontal Lobotomies Lie Detectors 1935: chimps who were neurotic before surgery became more relaxed after it 1930s: Egaz Moniz begins frontal lobotomies in humans (and eventually wins Nobel Prize) 1950s: psychosurgery in vogue; 40,000 frontal lobotomies in North America The story of Agnes (Kolb & Whishaw) no outward signs of emotion no facial expression no feelings toward other people (but still liked her dog) felt empty, zombie-like Other patients lose prosody = emotional component of speech orbitofrontal cortex Patients with damage can remember info but don t have emotions associated with it Polygraph tests are far from infallible In one study (Klein-muntz & Szucko, 1984), polygraph tests identified guilty person 76% of time but falsely accused a truth-teller 37% of the time Frontal patients show flat skin conductance to disturbing stimuli Right hemisphere specialized for emotion Happy or sad? Why? right hemisphere specialized for recognizing emotions Do the two hemispheres have different personalities? left hemisphere activated by positive emotions left frontal damage depressed sometimes overly catastrophic and weepy about injury diminished left hemisphere activation in depressed people right hemisphere activated by negative emotions right frontal damage fewer negative emotions often not appropriately upset or concerned about injury 5