L2 - slides Flashcards
(34 cards)
What are the main brain areas involved in motivation?
Amygdala, Orbitofrontal Cortex, Ventral Tegmental Area (VTA), Prefrontal Cortex, Striatum, Nucleus Accumbens, Hypothalamus, Hippocampus, and Anterior Cingulate Cortex.
What are the three main defensive reactions to threat?
Fight, Flight, and Freeze.
What is the function of the amygdala in fear responses?
The amygdala coordinates threat responses, expresses defensive behaviors, and regulates neurotransmitter release (adrenaline & cortisol).
How does the body react to a threat through the autonomic nervous system?
Increased blood pressure, increased heart rate, and slowed digestion.
How does the brain consolidate fear memories?
Through noradrenergic (adrenaline) and glucocorticoid (cortisol) projections to the amygdala & hippocampus.
Why does fear memory persist?
Fear memory is highly adaptive for survival but can also contribute to anxiety disorders like PTSD.
What is the difference between fear and anxiety?
Fear: Immediate response to an actual, present threat.
Anxiety: Sustained response to uncertain or unpredictable threats.
What factors increase fear generalization?
- Number of fear experiences.
- Intensity of the fear experience.
- Unpredictability of the threat.
- Trait anxiety (individual sensitivity to fear).
How does adrenaline affect fear memory?
Adrenaline strengthens fear memories via β-adrenergic receptors in the amygdala & hippocampus.
How do β-blockers (like propranolol) affect fear memory?
They disrupt the consolidation of fear memories if administered shortly after trauma.
How does cortisol affect fear memory?
Cortisol acts on glucocorticoid receptors in the amygdala & hippocampus, but its effects vary:
- In rats, cortisol impaired fear contextualization.
- In humans, cortisol administered after trauma reduced PTSD susceptibility.
What is extinction in fear learning?
Repeated non-reinforced re-exposure to a fear-inducing stimulus leads to a reduction in the learned fear response.
Why does extinction not erase fear memories?
The original fear memory remains intact, and fear can return through reinstatement, renewal, or spontaneous recovery.
What is reconsolidation, and how can it be used in therapy?
Fear memory can be edited during a temporary reconsolidation window after reactivation.
β-blockers (like propranolol) can be used to weaken the memory before it stabilizes again.
What is the evolutionary role of pleasure?
Pleasure motivates organisms to seek rewards necessary for survival and reproduction.
How is pleasure measured in animals?
Tongue protrusions in response to sweet tastes indicate pleasure.
How does sensory experience contribute to pleasure?
Taste, smell, look, and texture of rewards enhance their pleasure value.
What is alliesthesia?
A phenomenon where pleasure from a stimulus depends on current physiological needs (e.g., water tastes better when dehydrated).
What brain area is involved in pleasure and reward?
The nucleus accumbens (NAcc), part of the mesolimbic dopamine system.
What did Olds & Milner (1954) find about the nucleus accumbens?
Rats would self-stimulate their nucleus accumbens repeatedly, even at the cost of ignoring food and water.
What are hedonic hot spots?
Specific areas in the nucleus accumbens where opioids increase pleasure responses.
What is the difference between ‘wanting’ and ‘liking’?
‘Wanting’ (incentive salience) = dopamine-driven craving.
‘Liking’ = opioid-driven pleasure.
How does dopamine affect ‘wanting’?
Dopamine increases craving, even without increasing pleasure.
How does opioid stimulation affect ‘liking’?
Opioids increase pleasure but do not necessarily increase craving.
