Wk3 - Fear Conditioning Flashcards
What brain structure is crucial for fear conditioning?
Amygdala
Define fear conditioning
Creating a fear of an object or situation which was previously neutral
What are some examples of stimuli that can be conditioned?
Tone
Smell / Odour
Light
Context
What are examples of conditioned fear responses?
Autonomic NS activity (HR, BP)
Freezing behaviour
Release of hormones (norepinephrine, epinephrine, stress hormone / ACTH, cortisol)
What differs between organisms in terms of fear conditioning?
Fear response differs between type of organism
Where does fear conditioning occur?
Amygdala
What are the 3 nuclei in the amygdala?
Central nucleus
Lateral nucleus
Basal nucleus
What amygdala nuclei are needed for fear conditioning?
Central nucleus
Lateral nucleus
How was it found out that the central and lateral nuclei of the amygdala are involved in fear conditioning?
Lesions were made in the nuclei of a rat’s amygdala
Looked at the amount of time the rat froze in response to a stimulus, both before and after conditioning.
Control group of unoperated rats. Showed normal fear conditioning (longer freezing time after conditioning)
Found a lack of conditioned response to stimuli when lesions were to the entire amygdala or to the central or lateral nuclei
If CE and LA nuclei were intact, there was a successful conditioned response, even if other nuclei were lesioned
What is the sham condition in the rat experiment and what is it useful for?
Sham condition = operated on but no lesion made.
Shows whether it is the operation that is making the changing in conditioning.
Operating did not have an effect - there was still successful conditioning
What happened to the length of freezing time when either the whole amygdala, the CE nucleus, or the LA nucleus were lesioned?
Little difference in freezing time before and after conditioning. Did not freeze much in response to the conditioned stimulus. Suggests that fear conditioning was unsuccessful.
What nuclei in the amygdala are needed to create a fear?
Central nucleus
Lateral nucleus
What is the role of the lateral nucleus in fear conditioning?
Receives information from the environment and communicates this with the central nucleus
What is the central nucleus’ role in fear conditioning?
Responsible for the fear response (e.g., freezing)
Where does information regarding the neutral stimulus and unconditioned stimulus meet?
Dorsal half of the lateral nucleus of the amygdala