Three Minute Review: Motivation 1

• what drives people to behave the way they do?• regulatory drives

– homeostasis– thermostat analogy

• non-regulatory drives• hypothalamus

– tiny area, important functions, links with limbic system, 4F’s• Hunger

– “hunger centre” (LH) vs. “satiation centre” (VMH) – how does the body maintain the correct level of food intake?– interplay between VMH and LH

• see also more detailed explanations, Gray Ch. 6, FQ10– feeling full– blood glucose levels– fat cells secrete leptin

– 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

– eating disorders• anorexia nervosa• bulimia nervosa• have our cultural ideals become unreasonable?

Sex• What determines sex drive?

– Hormones• androgens • estrogens

– 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 • beauty, youth and sex

– Evolutionary theory• 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

• Many addictive drugs stimulate dopamine

Test YourselfWhich of the following could cause a rat to eat (true/false)?(From the lecture)• 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)• 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?)

Why have emotions?1. Emotions communicate

– consistent across cultures and even species

2. 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

What is this man from New Guinea feeling -- anger, happiness, disgust, sadness?

Video:Cavanagh:

Disk 3Emotion

Expression(2:10)

Dimensions of Emotion

Autonomic Nervous System

Fig. 5.4

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)?

Low Medium High

LEVEL OF AROUSAL

QUALITY OF PERFORMANCE

Arousal• How much coffee would you want to

drink if you were:– driving?– writing an exam?– giving an important talk for the first time?

Yerkes & Dodson (1908)

Rats could avoid shock by going into brighter of two compartments

QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.

Experimenters varied the strength of the shocks given to the rat and measured their accuracy at picking the brighter compartment.

Yerkes-Dodson Curve

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)

Theories of Emotion1. Common Sense Theory

Theories of Emotion2. James-Lange

“…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

Facial Feedback Theory

• Smiling makes you feel happier

Theories of Emotion3. Cannon-Bard Theory

Schachter’s ExperimentSchachter & 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• 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”Stanley Schachter

1922-1997

Schachter’s Results

Theories of Emotion4. Schachter’s Attribution Theory

Degree of Arousal = INTENSITY of Emotion

Cognitive appraisal = TYPE of Emotion

This figure is simpler than Fig. 6.24 (which you can ignore) in your text

Misattribution of Emotion• 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

Which woman is more attractive?

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)

Frontal Lobes

• Phineas Gage– “Gage is no longer Gage”

Frontal Lobotomies• 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

Lie Detectors

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