Lecture 3 - Emotion 1 Flashcards Preview

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Flashcards in Lecture 3 - Emotion 1 Deck (40)
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Define emotions

States elicited by rewarding or aversive stimuli and their omission or termination of stimuli
Can categorise


Define what a state is

Comprises thoughts “feelings” and physiological/behavioural responses to emotion


How can emotional stimuli be measured

Physiological or behavioural responses emotional stimuli unambiguously be measured

Fearful = heart rate blood pressure freezing


Outline evolutionary considerations of physiological and behavioural responses of emotion

Survival value
Relatively preserved throughout evolution
Principle organisation brain very similar along all mammalian species


Advantage of Rats as a model system

Easy breed and keep
Well established behavioural tests
Brain large enough apply selective manipulations to distinct brain structures
Brain anatomy very well characterised


Disadvantages of rats as model systems

Generic manipulations difficult


Outline Papez Theory of emotion 1937

Originally anatomical grounds
Hippocampus amygdala and hypothalamus linked higher cortical areas
Linked higher cognition
Lower areas brain stem control physiological responses


Outline Klüver and Bucys temporal lesion effect studies 1939

Temporal lobe lesion effects monkeys
Monkey act drunk


Outline MacLeans Limbic System Theory 1949

Lesion studies
Hippocampus emotional keyboard
Need play hippocampus trigger different emotional reactions


Outline 2 case studies in the prefrontal cortex

Phineas Gage - Harlow 1868

Nauta 1971


Outline Phineas Gage - Harlow 1868

Iron rod through brain
Personality and emotions changed substantially


Outline Nauta 1971

Frontal loves and interoception
Due to anatomical position
Sit between higher association cortices and brain stem
Good position anatomically play role in emotions


Outline role of Meso-corticolimbic dopamine system in emotions

Originates VTA and midbrain transmitted via dopamine

Brain stimulated induced reward

Neuroleptic induced anhedonia particularly dopamine. Mean failure experience reward properly


How can anxiety and fear be characterised without reference to subjective feelings

State causes by presence aversive stimulus


What has most animal research of emotion focused on last 30 years

Animal research brain substrates focused on fear and anxiety


What does fear and anxiety comprise of

Protective and defensive responses normally elected by aversive stimuli


How does Davis et al 2010 define fear

Plastic escape or avoidance responses to distinct aversive stimuli


Define anxiety

Tonic responses to diffuse aversive situations
Associated conflict and uncertainty
Different types fear and anxiety responses


What are fear and anxiety related disorders

Panic Disorder


Outline the classic fear conditioning paradigm - Phelps and LeDoux 2005

Stimulus neutral tone paired with aversive stimulus - foot shock
Later test sessions tone alone electors similar responses
Particularly closed environment
Responses: freezing protective action


Outline functional anatomical model of conditioned fear by Phelps and LeDoux 2005 in relation to lateral amygdala

Amygdala anatomically food position mediate fear responses
Input auditory systems and pain related
Somatosensory system
Come together in lateral amygdala
Linked affect systems could translate fear association into behavioural and physiological responses


Outline functional anatomical model of conditioned fear by Phelps and LeDoux 2005 in relation to central brain

Amygdala connections central brain important generating freezing response
Connections heart, thalamus, lateral hypothalamus and PG nucleus

Modulate blood pressure and hormone levels


What is the slippery slope of fear identified by LeDoux

Restricting use fear to denote feelings
Using threat induced defensive reactions help avoid misunderstandings brain mechanisms involved


What does the functional anatomical model of conditioned fear see the amygdala critical for

Threat induced defensive reactions
Lateral and central amygdala critical formation and expression CC fear behaviour


Amorapanth et al 2000 lateral and central amygdala in conditioned fear

Lesions electric current through areas brain want lesion damage it
Sham - insect group - pronounced freezing response no lesion
Amygdala lesions failed show fear response

Lesioned basal area no affect on fear response


Different central executive outputs mediate different conditioned fear responses

Electric and neurotoxin lesions
Lesion lateral hypothalamus = abolish increased blood pressure. Leave freezing response untouched

Lesion central gray area = blood pressure untouched. Freezing response abolished


Why is a neurotoxic lesion

Inject neurotoxin in to seas specifically only destroy neuroma within regions
Not damage fibres passage do through these regions coming from other areas


What are the areas of control of different fear responses found in neurotoxin research

Central gray = freezing response

Lateral hypothalamus = blood pressure

PVN = hormones


Outline fear conditioning related to plasticity in lateral amygdala neurons

Learning association auditory stimulus and foot shock occurs here

LA neurons come fire in response to tone
Use electrodes placed within lateral amygdala then record neuronal responses different stages fear conditioning experiments


How is the Amygdala measured in conditioned fear paradigms