Chapter 11 – Motivation and Emotion
Motivation – Concerns physiological and psychological processes underlying the initiation of
behaviors that direct organisms to specific goals.
Homeostasis – The body’s physiological processes that allows it to maintain consistent internal
states in response to the environment.
Drives – Physiological triggers that tell us that we are deprived of something and cause us to
seek it out (ex. Food)
Incentives – (or goals) Stimuli we seek to reduce drives.
▯ Physiological Aspects of Hunger
Satiation – The point in a meal where we are no longer motivated to eat.
“On” and “off” switch involved in hunger.
“On switch”, lateral hypothalamus
“Off switch”, ventromedial hypothalamus
Lateral hypothalamus stimulated by electricity in rats caused them to start eating.
▯ Psychological Aspects of Hunger
In some situations food can be a more powerful reinforce than highly addictive drugs.
“Sugar fix” imply that an addiction to candy bars is comparable to an addiction to drugs.
Taste is a powerful force behind motivation to eat.
▯ Tastes, Texture, and Eating
If the only factors in our motivation to eat were for calories and essential nutrients a few simple
foods would be consumed daily.
Taste and variety motivate decisions about what to eat.
Most popular foods are the most dietary fat and sugar.
We crave fats because we have receptors on the tongue that are sensitive to fat content
Fatty foods stimulate the pleasure sensing area of the brain.
Touch receptors in the mouth detect textures of the food and relay information to the orbitofrontal
▯ Food Variety and Eating
Bottomless Bowl of soup. Volunteers asked to eat soup until they were full.
Tube refilled bowl unknowingly to the volunteers.
Stopped consuming on average over 70% more than participants
that knowingly refilled their bowl.
They did not feel more satiated or believe that they had eaten
more than the other participants.
Unit Bias – The tendency to assume that the unit of proportion is an appropriate amount to
▯ Eating and Social Context
Eating is more than just a physical drive; there are social motives as well.
The presence of other people can either increase or decrease consumption of food.
Depends on the situation.
1) Social facilitation: Eating more – Hosts may encourage you to eat two or three
2) Impression management: Eating less – Sometime people are self conscious
and control their behavior so that others will see them in a certain way.
3) Modeling: Eating whatever they eat – See others as a “model” and eat whatever
they eat restraining their eating.
▯ Eating Disorder
Obesity – Positive balance of energy, energy intake exceeds energy expenditure.
Weightloss difficult, drive to eat and incentive value of food increase when deprived of it.
Obese people have higher metabolic activity in regions of the brain that respond to sensations in
the mouth, tongue and lips.
Anorexia Nervosa – Eating disorder that involves 1) Self starvation 2) fear of weight gain and
distorted view of self 3) denial of serious consequences of low weight.
Bulimia Nervosa Eating disorder that is characterized by periods of food deprivation, binge
eating, and purging.
Males less prone to these problems.
▯ Sexual Motivation
Libido The motivation for sexual activity and pleasure.
Generally believed that men are more interested in sex than women. ▯ Human Sexual behavior: Psychological and Biological Influences
Sex frequently without an end goal of reproduction.
Sex for reasons other than reproduction rare in nonhuman species.
Bonobos and dolphins have sex for no reason.
▯ Psychological Measures of Sexual Motivation
37% of the men he interviewed had at least one homosexual experience resulting in orgasm.
Only 13% in females.
Published his finding in what it known as “Kinsey reports”.
Questionnaire method of studying sexual motivation has continued.
Common reasons to have sex:
1) For physical reasons
2) To attain a goal.
a. To get a raise.
3) For emotional reasons
4) Because of insecurity
a. Felt obligated to
▯ Biological Measures of Sex
Sexual Response Cycle – Describes the phases of physiological change during sexual
Applies to both females and males.
There are differences between sexes in how stages are experienced and their duration.
Refractory Period – A time period during which erection and orgasm are not physically
▯ Sexual Dysfunction
Erectile Dysfunction (ED) – In males. The inability to maintain or achieve an erection.