Lecture 3: Fear Conditioning and Extinction

Question 1

What is fear conditioning?

Answer 1

Associating a stimulus with an aversive outcome

Question 2

What is extinction? How is it achieved?

Answer 2

Gradual reduction of fear response. Presentation of conditioning stimulus (CS) without unconditioned stimulus (US)

Question 3

What is classical conditioning?

Answer 3

Involuntary behaviour paired with stimulus

Question 4

What is operant conditioning?

Answer 4

Voluntary behaviour paired and consequence associated

Question 5

Does fear extinction create a new memory trace?

Answer 5

Yes. Does not erase original fear association.

Question 6

Under what three conditions can a fear response return?

Answer 6

1. Passage of time (spontaneous recovery)
2. New context (renewal)
3. Re-exposure to US (reinstatement)

Question 7

Fear extinction is thought to underlie ________ therapies for anxiety disorders.

Answer 7

Exposure.

Question 8

What studies have allowed fear conditioning to be mapper?

Answer 8

Animal studies.

Question 9

The low-road of fear conditioning: CS paired with US in i)___________; activation in ii)__________; iii)_________ sent to iv)_____________ regions; which control arousal, freezing, v)___________ responses.

Answer 9

i) basolateral nucleus of amygdala
ii) central nucleus
iii) afferents
iv) hypothalamic and midbrain regions
v) hormonal

The low-road of fear conditioning: CS paired with US in i)___________; activation in ii)__________; iii)_________ sent to iv)_____________ regions; which control arousal, freezing, v)___________ responses.

Question 10

Two characteristics of low-road of fear conditioning

Answer 10

1. automatic

2. rapid, reflexive

Question 11

The high-road of fear conditioning: i)________ to sensory cortex to ii)________

Answer 11

i) sensory thalamus

ii) amygdala

Question 12

Explain the features of the high-road of fear conditioning.

Answer 12

Slower, cortical inhibitory response (e.g. snake vs. stick)

Question 13

What are the two regions of rodent brain associated with fear and what is the effect of stimulation?

Answer 13

1. prelimbic (PL) cortex - increases fear

2. infralimbic (IL) cortex = reduces fear

Question 14

What areas were found to be associated with fear i) acquisition and ii) extinction in neuroimaging studies?

Answer 14

i) dorsal anterior cingulate cortex (dACC) thickness and activity
ii) ventromedial prefrontal cortex (vmPFC) thickness and activity

Question 15

List 3 possible reasons for a lack of amygdala activation in neuroimaging studies?

Answer 15

1. resolution
2. recruited only with intense threat (ethics prevents)
3. responses habituate over trials

Question 16

List 3 findings of fear conditioning in those with anxiety disorders.

Answer 16

1. greater conditionability to CS+
2. greater stimulus generalisation
3. impaired capacity to inhibiti fear to CS-

Question 17

________ of people exhibit PTSD symptoms in the week after trauma.

Answer 17

Majority.

Most reduce over following weeks.

Question 18

For fear conditioning, patients with PTSD have a _______ eitology, making it easier to treat with ___________.

Answer 18

Known. Exposure therapy.