Motivation: Eating, Hunger & Eating Disorders Flashcards
Define motivation.
It is what initiates, directs and maintains our behaviours.
Name the 5 main motivation theories.
Instinct theories. Maslow's hierachy of needs. Arousal theory. Drive-reduction theory. Incentive theory.
What is instinct theory?
Behaviours are motivated by instinct that is innate and which are activated by environmental stimuli. Instinct drives all human behaviours.
What did McDougall say instincts are?
Identified 18 different instincts (e.g. hunger, sex).
Instincts are unlearned, innate, automatic.
Trigger behaviours that aid in survival.
Many reflexes in humans show instinctive behaviour.
What is the main weakness of instinct theory?
Can’t explain all behaviours.
Hard to test.
What is Maslow’s hierarchy of need?
Basic survival needs to be satisfied before we are motivated to satisfy higher-level needs (e.g. self-esteem, self-actualisation).
Hierarchy.
What are the weaknesses of Maslow’s hierarchy of need?
Only the first 2 needs are hierarchical.
Humans are motivated by a complex array of needs.
Hard to test.
Culturally-specific.
What is optimal arousal theory?
Behaviour is motivated by the need to achieve optimum levels of arousal.
Behaviour is in response to a need to raise or lower arousal levels.
Individual differences in optimal arousal.
Explain the Yerkes-Dodson Law (arousal theory).
Arousal levels influence our performance. Complex tasks more affected.
What are the two primary arousal systems?
Autonomic nervous system - arouses body.
Cortical arousal system - arouses brain.
How is the ascending reticular activating system related to arousal?
Regulates wakefulness + sleep-wake transitions.
Connects reticular formation in brainstem to cortex via thalamus. Coma if these are damaged.
Selectively increases/decreases arousal + attention in cortex by modulating neurotransmitter systems.
What is drive reduction theory?
Motivation originates from biological needs to maintain the body in a state of equilibrium.
Physiological need creates an aroused tension state that motivates an organism to satisfy the need.
Homeostasis is the aim.
What are the three phases of digestion?
- Cephalic/reflex phase - initiated by sight, smell, thought or taste of food. Modulated by appetite. Preparatory processes.
- Gastric/absorptive phase - triggered by food in stomach. Distension of stomach + rise of pH. Activates muscle contractions.
- Intestinal phase - speeds/slows rate at which stomach empties.
What are the three main constituents of food that serve as fuel molecules?
carbohydrates, fats + proteins.
Which cells use the three main constituents that are absorbed into the bloodstream?
Glucose - carbohydrates.
Lipids - fats.
Amino acids - protein.
What are the 3 forms that energy is stored in the body?
Fat.
Glycogen - made + stored by liver and muscle.
Protein - broken down and used for energy when other stores are depleted.
Define homeostasis.
The maintenance of a steady internal state.
What are the two hypothesis for what creates the drive in drive-reduction theory?
Glucostatic and lipostatic hypothesis.
What is the glucostatic hypothesis?
Low blood glucose levels cause increased appetite and trigger eating. Glucose levels are highly regulated.
During/after eating - insulin levels increase. Insulin allows cells to make use of glucose and promotes storage of excess glucose as glycogen.
Explain where insulin is produced and what its role is in the body (evidence for this?).
Pancreas.
Enters brain and can reduce appetite. Controls appetite.
Evidence: mice with disrupted brain insulin receptors = higher food intake + obesity.
Explain how diabetes occurs.
Insulin levels too low.
Blood glucose too high (cells can’t make use of it).
Increased appetite + food intake. But glucose is excreted rather than used. Fat stores used up instead - weight loss.
What are the three other main appetite hormones (not insulin)?
Ghrelin, PYY, Leptin.