Lecture 3 - Emotion 1

Question 1

Define emotions

Answer 1

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

Question 2

Define what a state is

Answer 2

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

Question 3

How can emotional stimuli be measured

Answer 3

Physiological or behavioural responses emotional stimuli unambiguously be measured

Fearful = heart rate blood pressure freezing

Question 4

Outline evolutionary considerations of physiological and behavioural responses of emotion

Answer 4

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

Question 5

Advantage of Rats as a model system

Answer 5

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

Question 6

Disadvantages of rats as model systems

Answer 6

Generic manipulations difficult

Question 7

Outline Papez Theory of emotion 1937

Answer 7

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

Question 8

Outline Klüver and Bucys temporal lesion effect studies 1939

Answer 8

Temporal lobe lesion effects monkeys

Monkey act drunk

Question 9

Outline MacLeans Limbic System Theory 1949

Answer 9

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

Question 10

Outline 2 case studies in the prefrontal cortex

Answer 10

Phineas Gage - Harlow 1868

Nauta 1971

Question 11

Outline Phineas Gage - Harlow 1868

Answer 11

Iron rod through brain

Personality and emotions changed substantially

Question 12

Outline Nauta 1971

Answer 12

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

Question 13

Outline role of Meso-corticolimbic dopamine system in emotions

Answer 13

Originates VTA and midbrain transmitted via dopamine

Brain stimulated induced reward

Neuroleptic induced anhedonia particularly dopamine. Mean failure experience reward properly

Question 14

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

Answer 14

State causes by presence aversive stimulus

Question 15

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

Answer 15

Animal research brain substrates focused on fear and anxiety

Question 16

What does fear and anxiety comprise of

Answer 16

Protective and defensive responses normally elected by aversive stimuli

Question 17

How does Davis et al 2010 define fear

Answer 17

Plastic escape or avoidance responses to distinct aversive stimuli

Question 18

Define anxiety

Answer 18

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

Question 19

What are fear and anxiety related disorders

Answer 19

GAD 
OCD 
Panic Disorder 
Phobias 
PTSD

Question 20

Outline the classic fear conditioning paradigm - Phelps and LeDoux 2005

Answer 20

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

Question 21

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

Answer 21

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

Question 22

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

Answer 22

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

Modulate blood pressure and hormone levels

Question 23

What is the slippery slope of fear identified by LeDoux

Answer 23

Restricting use fear to denote feelings

Using threat induced defensive reactions help avoid misunderstandings brain mechanisms involved

Question 24

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

Answer 24

Threat induced defensive reactions

Lateral and central amygdala critical formation and expression CC fear behaviour

Question 25

Amorapanth et al 2000 lateral and central amygdala in conditioned fear

Answer 25

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

Question 26

Different central executive outputs mediate different conditioned fear responses

Answer 26

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

Question 27

Why is a neurotoxic lesion

Answer 27

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

Question 28

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

Answer 28

Central gray = freezing response Lateral hypothalamus = blood pressure PVN = hormones

Question 29

Outline fear conditioning related to plasticity in lateral amygdala neurons

Answer 29

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

Question 30

How is the Amygdala measured in conditioned fear paradigms

Answer 30

FMRI

Question 31

Outline Brchara et al 1995 study on the Amygdala and fear

Answer 31

Paired red and blue stimuli with shock Increase skin conductance response conditioned fear Declarative memory for shock pairing Physiological response impaired due to amygdala damage but still showed awareness this happened

Question 32

Outline LaBar et am 1998 study on amygdala and fear

Answer 32

MRI Combined fear conditioning paradigm FMRI signal change in relation fear conditioning in amygdala

Question 33

Why is there differences in research between Brchara et al 1995 and LaBar et al 1998

Answer 33

Differences in sensitivity and spatial resolution FMRI = metabolic changes related neuronal changes = indirect and larger areas signal is weaker Electrophysiological = look individual neurons Fear condition paradigm weaker fMRI as shock only to wrist

Question 34

Why should the role of the amygdala on fear be treated with caution

Answer 34

Other brain structures - hippocampus, pre frontal cortex important contributions Substrates conditioned fear may differ from those fear anxiety related behaviours Amygdala involves in other emotional and behavioural processes as well

Question 35

Outline relationship between hippocampus and fear and anxiety

Answer 35

Ventral hippocampus and conditioned freezing Ventral stream close interconnections with amygdala and hypothalamus Ventral hippocampus implicates innate unconditioned anxiety responses

Question 36

Outline how an elevated maze stage can measure hippocampus role in fear and anxiety

Answer 36

Rats spontaneously avoid open elevated spaces Spend time in closed arms Fear predators Lesion hippocampus or ventral hippocampus venture out closed arms more and less anxious

Question 37

Outline brightly lit test chamber can measure hippocampus role in fear and anxiety

Answer 37

Animal anxious of brightly lit areas Increased defecation = shit Shit themselves when go in to light Count how often shit themselves

Question 38

Hippocampus lesions increase time rats spent in open arms in the elevated plus maze. What does this finding indicate?

Answer 38

Hippocampal regions reduce anxiety

Question 39

Outline hippocampus and Anxiety Disorders

Answer 39

Taking out hippocampal region similar effects drugs used treat anxiety Anxiety drugs dampen down hippocampus

Question 40

Outline Bremner et al 2000 study on hippocampus and anxiety disorders

Answer 40

Studies panic disorders using radioactive labelled tracers Bind to benzodiazepine receptors Part of GABA receptor mediates inhibitory neural transmission More receptors = more Inhibition Decreased hippocampal benzodiazepine receptor binding in panic disorder Less Inhibition in hippocampus Too much hippocampal activity contributes to anxiety