Fear and Extinction Flashcards
(17 cards)
Define Alarm and its response.
Attentional reaction to possible threat; leads to orienting towards potentially threatening stimuli.
Define Fear and its response.
Cognitive/emotional reaction to clear, specific, and proximate threat; motivates escape or defense.
Define Stress and its response.
Physiological (fight-or-flight) reaction to stressors; enables escape or defense.
Define Anxiety and its response.
Cognitive/emotional reaction to situations where a threat may appear; leads to caution or hypervigilance.
Define Chronic Stress and its response.
Physiological impact of prolonged/uncontrollable exposure to stressors; results in burnout, learned helplessness, health deterioration.
Differentiate Fear and Anxiety based on duration, temporal focus, specificity of threat, and motivated response.
Fear: Brief duration; present temporal focus; specific, clear threat; facilitates escape.
Anxiety: Prolonged duration; future temporal focus; diffuse, poorly defined threat; caution & hypervigilance.
What are the benefits of studying fear and extinction, especially in rodents?
Identifying neural correlates of fear and anxiety.
Fear extinction is a model of exposure therapy.
Identification of improved treatments.
Identification of anxiety risk factors; impaired extinction predicts anxiety disorders.
Differentiate Learned Fear vs. Unlearned Fear.
Learned Fear: Response to objectively neutral stimulus/situation; previous experience taught it predicts danger.
Unlearned Fear: Reaction to objectively threatening stimulus/situation; innate and instinctive.
Outline the basic procedure of Pavlovian (Learned) Fear Conditioning.
Neutral stimulus (CS, e.g., noise) is presented.
CS co-terminates with a mild footshock (US).
Animal learns CS predicts danger.
Describe controllable vs. uncontrollable shock stress models and their impacts
Animal models where the organism’s ability to escape or avoid a stressor determines the resulting physiological and behavioral outcomes.
* Uncontrollable shock → enhanced and prolonged conditioned fear responses.
* Uncontrollable shock → learned helplessness (deficits in escape/avoidance, reduced motivation)
* Uncontrollable shock → persistent HPA axis activation; dysregulation (e.g., blunted negative feedback).
What brain structures are key to emotional memories (explicit vs. implicit)?
Hippocampus: Explicit (conscious recall) memory; contextual learning.
Amygdala: Implicit (emotional response) memory; integrates sensory/cortical/limbic info for emotional response.
Outline the roles of the Basolateral Amygdala (BLA) and Central Amygdala (CeA) in fear learning.
BLA: Integrates information from sensory cortices, thalamus, cortex, and hippocampus; becomes more sensitive to fear-predicting stimuli.
CeA: Sends outputs to hypothalamic and brainstem regions; coordinates behavioural fear responses.
What is the role of the Medial Prefrontal Cortex (mPFC) in fear?
Modulates amygdala activity (bi-directionally); critical for emotional regulation and cognitive/behavioral flexibility.
Define Fear Extinction.
Conditioned Stimulus (CS) is presented repeatedly without the Unconditioned Stimulus (US) → fear response to CS decreases.
Why is fear extinction not considered an ‘erasure’ of fear memory?
Relapse of conditioned fear occurs without re-training; evidence includes:
- Spontaneous Recovery: Fear returns after passage of time.
- Reinstatement: Fear returns after re-exposure to the US.
- Renewal: Fear returns when CS is presented in a different context than where extinction occurred (ABA/ABC renewal).
What is the current hypothesis for what happens during extinction?
An extinction memory (CS-noUS association) is formed that out-competes or suppresses the original fear memory (CS-US association).
What is the role of the Infralimbic Cortex (IL) in fear extinction?
Necessary for extinction; IL neurons drive activity in BLA extinction neurons to suppress fear.
