Motivation and Appetite

Question 1

Define motivation

Answer 1

• driver of directed behaviours; particularly our wants and needs
• involves both biological and social drives

Question 2

biological (primary) drives includes

Answer 2

thirst, hunger, oxygen, sleep, temperature regulation, waste elimination, sex

Question 3

social motives (secondary)

Answer 3

achievement, aggression, power, curiosity, play, affiliation, autonomy

Question 4

Approach motivation

Answer 4

drives propel engagement in some behaviours

Question 5

avoidance motivation

Answer 5

drives repel engagement in other behaviours

Question 6

Early approaches to measuring motivation –> Psychodynamic perspective (Freud)

Answer 6

• theorised that behaviours are motivated by unconscious and conscious desires, which are not in unison
• 3 theoretical constructs of psyche which freud proposed:
• -> id: unconscious, instinctual, irrational drives
• -> superego: morally responsible drives, operates at preconscious awareness
• -> ego: conscious, rational mind, ensures id and superego drives manifest appropriately
• criticisms: inability to validate or invalidate these theories - how can we measure unconscious desires?
• introduction of TATs (thematic apperception tests) which claimed to do so

Question 7

Drive Reduction Theory of motivation

Answer 7

• 1940s
• thirst, hunger and sexual frustration drive us to reduce the aversiveness of these states
• drives are hierarchical
• motivated to maintain psychological homeostasis
• constantly seeking to reduce internal unpleasant states

biological need –> drive –> organism motivated to satisfy drive –> goal directed behaviour –> need satisfied (homeostasis)

Question 8

Yerkes-Dodson law

Answer 8

• arousal effects strength of drives

- bell curve represents relationship between arousal level and performance quality (under arousal = stimulus hunger)

Question 9

What are clashing drives?

Answer 9

Approach approach conflict = choosing between 2 desirable options
Avoidance avoidance conflict = choosing between 2 difficult options
Approach avoidance conflict = both attracted and repelled to engage in the same goal (both approach and avoidance tendency increase as you get closer to the desired goal; however, avoidance tendencies increase faster than approach) –> maximum conflict when these intersect

Question 10

What are incentive theories?

Answer 10

• incentive theories build on Design Reduction theories (the DRT is inadequate as we repeatedly engage in behaviours despite satisfaction of drives) –> we are driven by positive goals
• different types of motivation: intrinsic (internally driven) or extrinsic (externally driven)
• 1973 study suggested that our intrinsic motivation can be devalued by extrinsic reinforcements

Question 11

What is the relative importance of needs?

Answer 11

• some physical and psychological needs are more important than others
• Murray identified 20 secondary needs belonging to 5 categories: ambition, materialism, power, affection and information

Question 12

Maslow’s hierarchy of needs

Answer 12

• 1954, formalised thinking in hierarchy of needs theory
• before we satisfy what occurs at the top, we need to satisfy the bottom needs
• top to bottom: self-actualization, self-esteem, love and belonging, safety and security, physiological needs

Question 13

Elaborate on sexual motivation and libido

Answer 13

• libido = human sexual desire

- psychological drivers of libido include testosterone and DRD4 related to dopamine (i.e. genetic component)

Question 14

Sexual response cycle

Answer 14

• Desire phase
• excitement / plateau phase starting to have physiological reactions
• orgasm phase
• resolution

Question 15

Goal setting:

Answer 15

• set SMART goals
• Specific
• Measurable
• Action oriented
• Realistic
• time based

Question 16

Define obesity:

Answer 16

determined by a person’s body mass index where a normal BMI is 18.5-25, overweight is 25-30 and 30+ is obese

Question 17

What bodily processes influences eating? –> Energy Levels

Answer 17

2 modes of energy storage:
- short term = glucose (less important for intake)
- long term = fat (more important for intake)
Changes in body fat affect appetite: homeostatic system
- fat cells secrete a hormone called leptin
- more fat = more leptin (suppressing appetite)
- less fat = less leptin (allowing food intake to increase)

Question 18

What bodily processes influences eating? –> sensation

Answer 18

Food flavour drives intake:
• Taste, smell and touch form flavour
• Hardwired to like sweet, salty and fatty things
Sensory specific satiety slows intake in a meal:
• The more we eat of a specific food, to more our liking for it declines
• It acts to signal the end of a meal (before stomach and gut signals tell your brain you are full)
It also drives variety

Question 19

What bodily processes effect eating? –> Digestive organs

Answer 19

Multiple systems are involved in digesting food and they all send signals to the brain about their status:
• Stomach is distended or empty
• Gut and stomach taste receptors
• Stomach is emptying its nutrient rich content (chyme) into the small intestine
• Gut bacterial signals of fat content

How do these signals communicate to the brain:
• Nerves (e.g. vagus nerve)
• Hormones (e.g. CCK [released when there is food in a stomach] and ghrelin [when the stomach is empty])
Nutrients (e.g. blood lipoproteins)

Question 20

List the bodily processes that influence eating:

Answer 20

• energy levels
• sensation
• digestive organs

Question 21

List thing that influence eating in the brain:

Answer 21

• neurochemicals –> serotonin, dopamine, leptin, grhelin

- important locations in brain = hypothalamus, cortical, limbic system

Question 22

Brain: influences eating through neurochemicals

Answer 22

• Many neurochemicals modulate eating
• 2 important examples are serotonin (SE) and dopamine (DA)
○ Increased levels of both suppress appetite
○ Most commercial appetite suppressants are SE or DA agonists (these drugs bind to SE or DA receptors)
○ Many common psychiatric drugs affect these neurotransmitters and so many also affect body weight as a side effect
• Neurochemicals are modulated by events in the body
○ Leptin (from fat cells) stimulates release of CRH (corticotrophin releasing hormone) in the brain, suppressing appetite
Grhelin (from stomach) stimulates release of NY (neuropeptide Y) in the brain increasing appetite

Question 23

Brain: influences eating through these important brain locations:

Answer 23

• hypothalamus
• -> (ventromedial nucleus = stop eating)
• -> lateral hypothalamus = start eating
• cortical (studying car accident victims with frontal lobe damage - consequences of impulsivity is overeating due to a decreased ability to regulate oneself)
• -> frontal (impulsivity)
• -> insula (interoception)
• limbic system (hippocampus - memory)

Question 24

How does the environment affect the way we eat?

Answer 24

• showing food: will trigger a desire to eat and a cephalic phase response (salivation, insulin release)
• being habit bound: i.e. eating at the same time and place each day
• people and leisure: physical presence of co-eaters and anticipation increases eating
• appetite stimulant = TV
• portion and plate: people tend to eat what is in front of them

Question 25

Take into account all these factors that contribute to our eating:

Answer 25

• When and how much we eat is mainly driven by environmental factors that we are not usually aware of - mindless eating - environment / brain
• Biological factors are probably only important at the extremes (starvation/gross over-indulgence) - body/brain
Conscious control of food intake probably only plays a small role - brain/self