emotion and motivation Flashcards
hunger - what areas of the brain are involved?
lateral hypothalamus = excitatory = causes release of orexigenic (makes you hungry) hormones like orexin and MCH
ventromedial nucleus = inhibitory = releases anorexigenic hormones
how does body fat influence hunger?
releases leptin, an anorexigenic hormone, in a negative feedback loop
how would you see how a hormone/brain region works?
remove it/deactivate it, in terms of the hormone e.g. a knockout mouse
what role do the hypothalamus and amygdala play in fear and aggression?
amygdala controls it, as shown in MRIs and lesions resulting in less fear
medial hypothalamus is responsible for affective aggression (aggression towards perceived source of stress)
lateral hypothalamus responsible for predatory aggression
what emotion/motivation does dopamine relate to and what experiment shows this?
dopaminergic neurons respond to surprise reward only
it does not equal pleasure/liking something, instead it drives wanting/motivation
rats learnt to push a lever that stimulated the mesolimbic pathway and caused dopamine release
linked to addiction
what experiment demonstrates that emotions influence decision making?
patients with impaired orbitofrontal cortex didn’t avoid/get scared at high risk options in gambling, unimpaired did
what is the Singer-Schachter theory?
does a sensory input trigger an emotion which causes a physiological response, or does the physiological response cause the emotion?
answer seems to be a mixture of cognitive interpretation and the physiological reaction to the sensory input, in order to cause an emotional response
how does leptin work?
excitatory - arcuate nucleus stimulated to release POMC, aMCH and CART, which inhibit lateral hypothalamus and it’s orexin production
these also excite paraventricular nucleus which inhibits eating
inhibitory - arcuate nucleus inhibited form releasing NPY and AgRP which would normally increase orexin
these inhibit paraventricular nucleus, stopping it from causing eating
how does the paraventricular nucleus effect metabolic rate?
if excited, it excites the pituitary gland, which releases TSH and ACTH which increase metabolic rate, which inhibits body fat from producing leptin, therefore increasing hunger
in what two ways does a full stomach decrease apetite?
inhibits ghrelin
excites solitary nucleus of the brainstem which reduces hunger
how do blood glucose levels effect hunger?
if high, insulin is produced, which then goes along the arcuate nucleus pathway
(excites and causes POMC, aMCH and CART release which reduce orexin)
inhibits NPY and AgRP which increase orexin
what was the common sense theory?
that sensory input = emotional response = physiological reaction
James-Lange theory?
sensory input = physiological reaction = emotional experience
cannon-Bard theory?
emotional experience arises thalamus signalling to neocortex while the physiological reaction arises from thalamus signalling to hypothalamus
