Chapter Ten Notes
Motivation and Emotion
1. What is the distinction between drive and incentive theories of motivation?
- A drive is an internal state of tension (disruptions of our equilibrium) that motivates an
organism to engage in activities that should reduce this tension.
(Example) If we go without food, we start to experience discomfort, and our internal tension
(the drive) motivates us to get food, so that we are once again satisfied.
- Incentive theories are external goals that have the capacity to motivate our behavior.
(Example) Ice cream, a juicy steak, an A on an exam, approval from friends, etc...
- Drive theories emphasize how an internal state of tension push people in a certain direction,
and the incentive theory emphasizes how external stimuli pull people in certain directions.
- For drive, motivation lies within the organism, and for incentive theories, the motivation lies
outside the organism, in the environment.
2. How do evolutionary theories explain various motives?
- They believe that motives are a product of natural selection that has adaptive value
(dominance, achievement, aggression, affiliation, sex drive, etc…).
- Evolutionary perspective assert that human motives, and other species, are products of
3. What are the two major categories of human motives?
- Biological motives that originate in bodily needs such as hunger, thirst, sleep, sex, and
- Psychosocial (social) motives that originate in social experiences, such as the need for
achievement, dominance, independence, amusement, etc…
- Motives are the needs, wants, interests, and desires that propel people in certain directions.
- In short, Motivation involves goal-directed behavior
- Organisms seek to maintain homeostasis “a state of physiological equilibrium/stability”.
(Example), our bodies reach a temperature of 37 degrees Celsius; if it goes up, we sweat, if it
goes down, we shiver, which is designed to help our body go back to its normal temp. Our body
reacts like this, so that it can go back to its normal equilibrium.
4. Which brain centres appear to control the experience of hunger?
- The hypothalamus:
!Lateral Hypothalamus (LH): if you cut this part of the brain, then there no interest in eating,
as if hunger was destroyed
!Ventromedial nucleus of the Hypothalamus (VMH): if you cut this part of the brain, then
you eat excessively, gain weight, and the feeling of “fullness” will no longer be there.
- Therefore the LH and the VMH (elements in neural circuitry) are the brains on-off switches for the
control of hunger.
- Although the paraventricular nucleus (PVN) in the hypothalamus, plays a larger role in hunger.
!Paraventricular nucleus (PVN): contains a group of neuron that is sensitive to incoming hunger
signals and another group of neurons that respond to satiety signals.
5. How do fluctuations in blood glucose and hormones contribute to hunger?
- Things that decrease blood glucose level can increase hunger
- Things that increase blood glucose level can make people feel satiated (full/satisfied).
- Fluctuations in blood glucose monitored by glucostats also influence hunger.
- Insulin secrete (release) also plays a role in the fluctuation of hunger (increases hunger).
- New hormone called leptin, which is produced by fat cells throughout the body and released
into the blood stream, regulates hunger as well.
!When leptin levels are high, the tendency to feel hungry reduces; Leptin activates receptors in
the brain that inhibit the release of neuropeptide Y, which leads to the activity in the (PVN)
hypothalamus, which inhibits eating.
6. How is eating influenced by the availability of food, learning habits, and stress?
-Hunger is a biological need, although social and environmental factors such as, the
availability of food, learning habits, and stress govern eating.
!Availability of food: The presence of tasty food often leads people to eat even though they
are already quite full from eating before. The incentive view shows that hunger is influenced
by food availability and palatability. As you eat a specific food, its incentive value declines,
which is called “sensory-specific-satiety”.
!Learning habits: People from different cultures display very different patterns of food
consumption (everyone doesn’t eat the same things). Learning has a great deal of influence
over what people prefer to eat. This learning can be associated with classical conditioning
(at hockey games, there are hotdog stands, so people associate hockey with hotdog stands, or
conditioned to prefer flavors with foods with high caloric intake….). It can also be associated
with observational learning (children are more likely to try an unfamiliar food if an adult
tries it first)
!Stress: Studies suggest that stress-induced (encourage) eating may be more common
among chronic dieters, and that stress-induced physiological arousal rather than stress itself
stimulates eating. Also, it is the negative emotions often evoked by stress that promote
7. How common and how dangerous is obesity?
- Obesity is a significant healthy problem that elevates ones risk for many diseases.
- Canada’s obesity rate is 15% lower than the U.S, where 1/5 adults is obese, although we may
be headed towards the same statistic, since obesity rates has doubled in Canada in the last 2