emotion and motivation

Question 1

what are the mechanisms regulating hunger?

Answer 1

lateral hypothalamus - induces hunger (orexigenic)
ventromedial nucleus - induces satiety (anorexigenic)
paraventricular nucleus - induces satiety (anorexigenic)

Question 2

what is leptin?

Answer 2

a hormone produced by body fat that reduces fat

Question 3

how does leptin reduce body fat?

Answer 3

1. activating neurons in arcuate nucleus which activate parts of the brain to induce either satiety or hunger
2. neurons in arcuate nucleus can also directly alter metabolic rate

Question 4

how are neurons in arcuate nucleus (in hypothalamus) affected by leptin?

Answer 4

neurons have receptors for leptin
- some are excited by leptin and secrete peptides which suppress lateral hypothalamus (induces hunger)
- others are suppressed by leptin and secrete peptides which activate lateral hypothalamus

Question 5

how does leptin affect metabolic rate?

Answer 5

neurons in arcuate nucleus use
- sympathetic nervous system to increase metabolic rate
- parasympathetic nervous system to decrease metabolic rate

Question 6

how does blood glucose regulate hunger?

Answer 6

lateral hypothalamus and ventromedial nucleus have glucose receptors
high blood glucose produces insulin which effect neurons in arcuate nucleus which modulate hunger and satiety signals

Question 7

what is Ghrelin?

Answer 7

a hormone that induces hunger, produced when there is no food in stomach

Question 8

what is GLP-1?

Answer 8

peptide hormone that enhances release of insulin and induces satiety
GLP-1 agonists mimic GLP-1 can help obese people lose weight by reducing appetite

Question 9

what mediates fear?

Answer 9

amygdala
lesion in amygdala = animals show less fear after conditioning fear response

Question 10

what brain areas are involved in aggression?

Answer 10

amygdala and hypothalamus

Question 11

evidence that the hypothalamus causes aggression?

Answer 11

when hypothalamus is stimulated with electrodes causes aggressive behaviour
medial hypothalamus mediates ‘affective’ (emotional) aggression
lateral hypothalamus mediates ‘predatory’ aggression

Question 12

what is the role of dopamine?

Answer 12

encodes reward prediction error (surprise)

Question 13

experimental evidence demonstrating role of dopamine

Answer 13

monkey conditioned by rewarding him with grape juice every time the light turns on
eventually dopaminergic neurons respond to light instead of reward

Question 14

experimental evidence of the role of emotion in decision-making

Answer 14

participants chose cards from one of two decks, deck B is more risky
- control participants avoid deck B and show stress response (sweating) when hovering over it
- patients with orbitofrontal lesions don’t avoid deck B and don’t show stress response

Question 15

how does emotion interact with decision-making?

Answer 15

when decision-making you consider your physiological reactions caused by emotions

Question 16

what is the James-Lange theory for how emotions are made?

Answer 16

physiological reaction is unconscious, your mental interpretation of this creates your emotional experience

Question 17

what is the common sense theory for how emotions are made?

Answer 17

your emotional reaction to an event triggers a physiological reaction

Question 18

what is the cannon-bard theory for how emotions are made?

Answer 18

sensory input influences both emotional experience and physiological reaction simultaneously

Question 19

what is the Singer-Schacter theory for how emotions are made?

Answer 19

interaction between physiological reaction and cognitive interpretation produce the emotional experience

Question 20

what are constructivist theories for how emotions are made?

Answer 20

cognitive interpretation is influenced by culture and experience, and physiological output
- this produces the emotional experience