Chapter 5 Motivation and Emotion. The Case of D.W. 1930s –young child subsisted on diet of salt and water Ate salt directly, drank water at any opportunity

Chapter 5

Motivation and Emotion

The Case of D.W.

• 1930s– young child subsisted on diet of salt and water

• Ate salt directly, drank water at any opportunity– became agitated if denied

• Died following attempt to control diet• Salt need due to cancer of adrenal glands

Motivation

• The factors that cause organisms to behave the way they do– the “why” of psychology

• Hedonism– the basic motivation to seek pleasure and avoid

pain

• Motivation is closely linked to emotion– affective psychological experience– associated with arousal

Motivation

• Motivating factors come from a variety of sources:

– evolutionary

– physiological

– psychological

– sociolocultural

Physiological Basesof Motivation

• Neuroendocrine System

Neuroendocrine System

• Communication system– Endocrine glands and brain structures

• network of neurons that communicate with hormones through the circulatory system

Hormones

• Biologically active chemicals– e.g. peptide, protein or steroid

• Bind to target tissues around the body– Regulate hunger and thirst– Influence development of primary and

secondary sexual characteristics– Influence mating behaviors– Regulate immune function

Neuroendocrine Regulation

• Hypothalamus– structure at the base of the brain– regulates sexual behavior, temperature,

hunger and thirst– monitors blood levels of hormones and

nutrients– directs other glands to produce appropriate

hormones

Homeostasis

• The maintenance of a balanced system through self-regulation

• Homeostasis is maintained through negative feedback– movement away from a set point results in

compensatory responses to restore the balance

Temperature:An Example of Homeostasis

98 set point

Sympathetic:Vasoconstriction

Shivering

98 set point98 set point

Involuntary Mechanisms


98 set point

Parasympathetic:Vasodilation

Sweating


Involuntary Mechanisms


98 set point

CNS:Put on jacket


Voluntary Mechanisms


98 set point

CNS:Take off

jacket


Voluntary Mechanisms

Behavioral Regulation

• Adaptive behaviors that help achieve a homeostatic state– e.g. eating important nutrients, drinking

water

Regulation of Water and Salt

• Maintain salt balance similar to ocean

• Two types of thirst:– Osmotic Thirst

• when concentration of solutes in tissues exceeds 0.15M

• can result in specific appetite for water(e.g. DW)

– Hypovolemic thirst• results from abnormally low blood volume

Drive States

• Primary Motivation– Instinctive or biologically motivated

behavior• e.g. fixed action patterns

• Drive Reduction (Clark L. Hull)– motivation based on reducing needs and

restoring homeostasis

Acquired Motivation

• Not all motivating factors are instinctive

• Acquired Motivation: – Motives learned over a lifetime

• e.g. money as reward

• Sometimes called Incentive Motivation– Incentives: goals that motivate behavior

Eating as Motivated Behavior

• Many factors lead to selection and ingestion of foods– Genetic– Psychological– Sociocultural

Closed Feeding Systems

• Usually found in animals with simple nervous systems

• Reflexive responses to a narrow range of foods– e.g. fly

• feeding initiated by receptors on leg• only feeds on specific foods

Open Feeding Systems

• Wide variety of food choices– Animals must learn what is good to eat

• Omnivore’s Paradox– greater selection of food increases

available nutrition but also increases likelihood of poisoning

• omnivores are typically neophobic• suggests instincts still important in food choice

Nutritional Wisdom

• Innate predisposition to make adaptive food choices

• Infants – innate preference for sweet– dislike bitter and sour (indicative of poison)

Taste Cues

• Rats prefer familiar tastes– Will switch to new foods if familiar foods

are nutritionally deficient (e.g. reduced thiamine)

• We tend to eat foods that made us feel good in the past

Feeding Jags

• Eating one food type for extended periods– e.g. kids eating peanut butter sandwiches– jag ends when switch to another food type

• May be a response to a specific nutritional deficiency

• Variety increases nutritional intake– switching foods because of new deficiency

Sensory-Specific Satiety

• Get full eating one type of food during meal– Can continue eating if offered another food

(e.g. dessert)

• Increases variety of intake

Evolution of Food Selection

• Biocultural Evolution– selection of certain foods increases the

fitness of individuals in a culture• e.g. food combinations

• Recipes and preferences transferred from one generation to next– Meme: extragenetic information transfer

Genetics

• Lactose Intolerance– due to recessive gene leading to lower

levels of lactase– common in Asian and some African

populations

Brain Mechanisms

• Hypothalamus

Hypothalamus and Eating

• Dual-Center Model of Hunger– Damage to the Lateral Nucleus

of the Hypothalamus in rats results in aphagia (loss of eating)

– Damage to Ventromedial Nucleus of the Hypothalamus results in hyperphagia and obesity

Hypothalamus and Eating

• Dual-Center Model of Hunger– Lateral Nucleus is the “start eating” center

• stimulating leads to onset of eating• when damaged, rats will not start eating

– Ventromedial Nucleus is the “stop eating” center

• when damaged, rats will not stop eating

Problems with theDual Center Model

• Stimulating the Lateral Nucleus of the Hypothalamus leads to a wide variety of motivated behaviors– drinking– copulation


• Damaging the lateral hypothalamus also damages other pathways– especially dopamine-rich nerves that come

from areas associated with arousal and pleasure


• However,– Lateral Hypothalamus interacts with brain

structures involved in feeding• also interacts with pancreas

– Calling it the “start-eating” center was too simple


• Ventromedial Hypothalamus– Ventromedial-damaged rats only overeat

foods that taste good– Rats gain weight, even if put on a strict diet

• produce abnormally high levels of insulin - leads to greater fat storage

Insulin and Blood Glucose

• Homeostasis of blood glucose levels– Increased blood glucose following meal

leads to an increase in insulin from pancreas

• Results in storage of glucose as glycogen or fat

– Low glucose levels leads to an increase in glucagon from pancreas

• Results in conversion of glycogen back to glucose

Pleasure

• Humans are genetically predisposed to seek pleasure and avoid pain– promote survival and reproduction

Brain Mechanisms for Pleasure

• Electrical Stimulation of the Brain (ESB)– Simulating medial forebrain bundle (MFB)

appears to be pleasurable to rats– Stimulating other brain structures can also

be effective

• Rats prefer to stimulate their brains over eating

Pleasure Seekingin Humans

• ESB in humans results in reports of pleasure– Similarities to crack cocaine ingestion

• crack activates dopamine receptors that have been implicated in ESB in rats

Acquired Pleasures

• Not all behaviors are motivated by primary needs– Acquired pleasures can act as secondary

reinforcers– Acquired pleasures need not be necessary

for survival• But, you must meet the primary needs first

Hierarchy of Needs

• Abraham Maslow– once biological needs are met, humans

can gain social, esteem and self-actualization needs

Intrinsic vs. Extrinsic Motivators

• Intrinsic Motivation– motivation to achieve self-satisfaction

• e.g. simple curiosity

• Extrinsic Motivation– motivation to meet the standards of others

• e.g. working for money

Intrinsically-Motivated People

• Task-oriented• Gain satisfaction from task, not rewards• Often achieve more than those motivated

by extrinsic factors• Display:

– A quest for mastery– A drive to work– Less interested in competition

Overjustification Effect

• A decrease in intrinsic motivation when an extrinsic motivator is offered– e.g. 3- to 5-year-olds show less interest in

school activities when they were rewarded than before

Need for Achievement

• Motivation to accomplish a challenging task quickly and effectively– can be measured as a personality characteristic

• People with a high need for achievement:– work harder– are more future oriented– are willing to delay gratification– tend to choose realistic goals, not challenging

goals

Emotions

• Are emotions innate?

• Darwin: The Expression of Emotion in Man and Animals– Emotional behavior is adaptive– Emotions organize behavior and

communicate intent

Emotions

• Human emotional displays are similar to other animals

Emotion in Humans

• Basic emotions:– Anger– Disgust– Fear– Interest– Joy– Surprise– Sadness

Expressions of Emotion

• Cultural differences– not all cultures describe emotions in the

same way


• Facial Expressions– all cultures can

display and recognize emotions in a similar manner


• Facial Expressions– cultures differ in acceptability of emotional

expression• e.g. Japan: polite smile as substitute for display

of disgust

Biological Bases of Emotions

• Limbic System– subcortical region– amygdala receives input from sensory

systems– amygdala initiates activity in medulla,

pons and spinal cord• sympathetic nervous system activity

– fight of flight

Amygdala Damage

• Impairs ability to recognize emotional expression

Biological Bases of Emotions

• Frontal Lobes– interacts with the amygdala– generates movements for emotional

expression– may be involved in interpretation of others’

emotions

• Frontal lobotomy– Surgically disconnecting frontal lobes reduces

emotionality

Theories of Emotion

• Which came first?– the emotion or the emotional

response?

Theories of Emotion

• The James-Lange Theory– Body becomes aroused THEN person

becomes emotional– Pattern of arousal indicates your emotional

state– Emotion is the awareness of one’s bodily

response to a given stimulus

Theories of Emotion

William Cannon’s objections to the James-Lange Theory:

– physiological arousal alone is not enough to trigger emotion

– similar patterns of arousal are associated with different emotions

Theories of Emotion

• The Cannon-Bard Theory– Emotionally-arousing stimuli activity the

brain leading to arousal and emotion• arousal and emotion are simultaneous

– Subcortical brain areas are assumed to be important

Theories of Emotion

• Schacter’s Emotional Attribution Theory– Body becomes aroused then person

appraises the stimulus and shows an appropriate responses

– e.g. both fear and elation lead to increased heart rate

• the situation you are in determines whether you attribute the increased heart rate to fear or happiness.

Schacter and Singer (1962)

• Studied emotional responses to increased arousal caused by a drug injection (epinephrine)– Epinephrine causes increased heart rate,

general warming sensation and arousal


• Some subjects told the side effects, others were not

• All subjects were placed in a room with an experimental confederate– Confederate either acted euphoric or acted

angry


• Subjects who received the drug and were not told its effects took on the emotion of the experimental confederate– No effect if told what the side effects of the

drug were

• Increased arousal attributed to the emotional situation

Summary of Theories of Emotions

Documents

Chapter 5 Motivation and Emotion. The Case of D.W. 1930s –young child subsisted on diet of salt and water Ate salt directly, drank water at any opportunity