1
Hunger Motivation
Human beings get hungry and need to eat, do so, and then get full, which is the point at which they cannot eat
anymore (_________________).
Researchers have investigated which signals from the ___________ and ____________ cause a person to become
hungry, as well as which signals indicate satiety.
Minnesota Starvation Experiment (Ancel Keyes)
Purpose of the Study?
Why use conscientious objectors?
Psychological changes?
Washburn and Cannon
What happened to Keyes?
Physiological changes?
Long-term impact of the research?
2
The Physiology of Hunger
• Stomach ____________________ (pangs) send signals to the brain making us aware of our
hunger. When our stomach expands we feel ____________.
• But, research has shown that _______________ persists without stomach pangs: Tsang (1938)
_________________ rat stomachs, connected the esophagus to the small intestines, and the
rats still felt hungry (and ate food).
• The same holds true for people who have had their stomachs removed for ______________
treatment. Also, people who have had their stomachs filled by surgical ________________ had
“full” stomachs but still did not feel satiated.
• Levels of _______________ in the blood are monitored by receptors (neurons) in the stomach,
liver, and intestines.
o They send signals to the _________________________ in the brain.
 Glucose is the form of sugar that circulates in the blood and provides the major
source of __________________ for the body tissues. When its levels are
___________, we feel hungry.
o Blood vessels supply the hypothalamus, enabling it to respond to our current blood
chemistry as well as to incoming ______________ information about the body’s state.
One of its tasks is monitoring levels of _________________ hormones.
Hormone
Location
Insulin
Pancreas
Control blood glucose
Ghrelin
Empty stomach
“I’m hungry” signals
Orexin
Hypothalamus
Hunger-triggering
Leptin (protein
Fat cells
When abundant, causes brain to increase
metabolism and decrease hunger
PYY
Digestive tract
“I’m not hungry” signal
hormone)
•
•
•
Activity
The _________________ hypothalamus (LH) brings on hunger.
o Destroy the LH, and an animal has no interest in eating.
The _________________________ hypothalamus (VMH) depresses hunger (makes you feel full).
o Destroy the VMH, and an animal eats excessively.
Set Point
o The interaction of appetite hormones and brain activity suggest that the body has some
sort of “_________________________________________”.
o When the body falls below the set point—or the point at which an individual’s “weight
thermostat” is supposedly set—an ___________________ in hunger and a lowered
_______________________ rate may act to restore the lost weight.
o This set point is influenced in part by ______________________.
3
o
Limits
 It doesn’t address ____________, ___________________ changes in body
weight that can alter a person’s set point.
 It doesn’t address overeating and weight gain when we have ______________
access to a wide variety of tasty foods.
 It doesn’t explain why ________________________ factors influence hunger.
 Many prefer the term “settling point or set range”.
The Psychology of Hunger
• _________________ plays an important role in hunger. Due to difficulties with _____________,
amnesia patients eat frequently if given food (Rozin et al., 1998).
• This suggests that part of knowing ___________ to eat is our memory of our last meal.
• Body chemistry and environmental factors influence not only when we feel hunger but _______
we feel hungry for!
o We eat more when eating with _________________.
o When offered a _______________________ portion, we put away more calories.
o When given a large serving ____________________ or a large bowl/plate, we take more
food.
Obesity
• Obesity is a disorder characterized by being _________________________________________.
• Obesity increases the risk for ____________ issues like cardiovascular diseases, diabetes,
hypertension, arthritis, and back problems. In ______________, there is an increased risk of
late-life cognitive decline.
• A BMI of _______ or more = obese.
• Obesity in ______________________ increases their risk of diabetes, high blood pressure, heart
disease, gallstones, arthritis, and certain types of cancer, thus shortening their life-expectancy.
In addition, obese children are much more likely to suffer ___________________.
• Fat Cells: There are ______________________ fat cells in the body. These cells can increase in
___________ (2-3 times their normal size) and _______________ (75 billion) in an obese
individual (Sjöstrum, 1980).
• Studies reveal that body weight has a __________________ basis:
o ____________________ twins have closely similar weights, even when reared apart.
o Given an obese parent, boys are ___x more likely, and girls ___x more likely to be obese
than those with normal-weight parents.
o Adoptive siblings’ body weights are ____________________; people’s weights resemble
those of their biological parents and siblings.
• Social Effects of Obesity
o When female job applicants were made to look overweight, subjects were _________
willing to hire them.
• Activity
o Lack of _____________________ is a major contributor to obesity.
o Just watching TV for two hours resulted in a ______% increase of weight when other
factors were controlled (Hu & others, 2003).
4
•
Food Consumption
o Over the past 40 years, average weight gain has __________________. Health
professionals are pleading with US citizens to limit their food intake.
Eating Disorders
• Anorexia Nervosa
o A condition in which a normal-weight person (usually an adolescent woman)
______________________ loses weight but still feels overweight. They remain
_______________ with losing weight, and sometimes exercise excessively.
o Usually _______________________ and 9 times out of 10 ______________.
• Bulimia Nervosa
o A ____________________________ disorder characterized by episodes of overeating,
usually high-calorie foods, followed by vomiting, using laxatives, fasting, or excessive
exercise. ____________________ and ______________ follow binges. Weight
fluctuations as usually within or above normal ranges (easier to hide)
What is Operation Beautiful?
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Social Motivation
“[Man] is a social animal,” (Aristotle).
___________________ from others increases our need to belong.
Research Findings on Belongingness (Affiliation Need)
1. Wanting to Belong: The need to belong colors our ________________ and _______________.
2. Social Acceptance: A sense of belonging with others increases our ____________________.
Social segregation decreases it.
3. Maintaining Relationships: We ______________ breaking social bonds, even bad ones.
4. Ostracism: Social exclusion leads to ___________________, ________________, and at times
nasty behavior.
Respond to the following questions on your own…
Have social networking sites made
us more, or less, socially isolated?
Explain.
Do social networking profiles
reflect people’s actual
personalities? Explain.
Does social networking promote
narcissism (self-importance)?