PS234 Exam 2

classical conditioning

pavlov

• learn to associate 2 stimuli

• 1 stimulus elicits a response that was OG elicited only by the other stimulus

Unconditioned stimulus (US)

stimulus that naturally automatically elicits a reflexive or innate response w/o prior knowledge

• ex: offer of mint

Unconditioned Response (UR)

unlearned reflexive or innate response elicited by the UCS w/o prior learning

• ex: yes (to the mint)

Conditioned Stimulus (CS)

An OG neutral stimulus, that, after association w/ the US, elicits a ____

• ex: the sound of reboot

Conditioned Response (CR)

learned response elicited by a CS

• ex: yes (to the mint)

Apetitive conditioning

when arrival of US is a positive event (food)

Aversive conditioning

when arrival of US is a negative event (shock)

• ex: air puff

Air puff eye blink trial

example of aversive conditioning = CS → CR prepares to avoid US

• CS = tone or light; produces a gradual eye closure (GCR)

• rabbits = nictitating membrane

  • pair w/ shocking cheek of rabbit = UCS

    • tone signals shock → eye blink

  • hundreds of trials to learn for rabbits

• not as many trials for humans

Conditioned Emotional Response (CER)

When CR is an emotional response (fear/anxiety)

• ex: Little Albert

Little Albert

CER example

• UCS = bang

• UCR = fear, startled

• CS = white rat

• CR = fear, startled

Classical Excitatory Conditioning

CS elicits a response that is similar or identical to UR

Classical Inhibitory conditioning

CS elicits a response (CR) that is different or opposite to UR

Acquisition

the establishing + strengthening of the CR

Extinction

process in which CS presented in absence of US

• causes CR to weaken and eventually disappear

extinction steps

breaking the association between CS + US can extinguish new CS→CR reflex:

• present the CS alone repeatedly

• initially, CS evokes strong CRs

• w/ repetition, however, CS becomes less effective, similar to beginning of training

Doesn’t erase the CS-US connection, just inhibits

• stress, new context, and/or passage of time can make the CS effective again

  • suggests that classically conditioned memory survived extinction

Spontaneous recovery

after a rest period, and w/o any new learning trials, the reappearance of a previously extinguished CR

• usually weaker initial CR, extinguishes more rapidly

ex: abstinent person who used to have SUD

• drove by the house that they used to buy drugs at

  • all of a sudden, craving comes back

stimulus generalization

stimuli similar to initial CS elicits a CR

• aids in survival (ex: bit by a dog)

• depends on the person what is considered similar enough

• ex: Little Albert

  • OG CS is white rat, similar stimuli is a white mask = elicited same response

addiction

the classical conditioning responses stronger (going to a bar is a trigger)

• but the actual physical dependence doesn’t last as long

discrimination

CR occurs to one stimulus but not another

• discriminate between a car alarm + fire alarm in a building you’re in → should elicit fear

Positive Contingency

one stimulus occurs w/ another stimulus

• CS consistently followed by US

• ex: doorbell + visitor

classical excitatory conditioning

CS elicits a response similar to or identical w/ UR

• everything is mostly positive contingency

Negative Contingency

presence of one stimulus signals the absence of the other

• CS consistently followed by the absence US

• to test if inhibitory

  • generates mild or slow CR

Classical inhibitory conditioning

2 diff conditioned stimuli

• red folder → pop quiz → anxiety

• black folder → no quiz → no anxiety

  • ex: parent is an inhibitory stimulus (ex: don’t drink, etc.)

• to test if inhibitory

  • generates mild or slow CR

forward delay

US is shown when CS is still present (after a pasue; NOT simultaneous)

• more association

  • expands on Aristotle and contiguity

• experiments use this method

forward trace

US follows CS after some time

• less association

simultaneous

CS + US at exact same time

• does not have the predictive nature for learning

• ex: will never learn that A signals B, bc they show up at the exact same time

backward

US onset followed by CS

• still no predictive nature

• ex: A comes after B, no signaling/predicting

• ex: to a kid, lollipop after dr’s visit; sprite after chemo

  • probably due to intensity of stimulus ie chemo → stimulus variable

CS-US interval

200 milliseconds to 2 seconds to discern the 2 stimulus as separate

• “optimal stimulus interval”

exception for CS-US interval

taste aversion

• ex: food poisoning from sushi → no longer eat sushi

• ex: getting sick from one specific type of alcohol → never drinking that

• such a long time gap between the eating of food + getting sick; takes one trial

  • the aversion can last for years

CS-US trials

typically the more the better but you do reach a point of maximal learning

• i am learning → I have learned

asymptote

I am learning → I have learned

• you learned to the max

variables about stimuli that affect conditioning

• intensity of stimulus

• familiarity/previous experience

• biological relevance

• presence of extraneous stimuli

Intensity

strength + salience

• salience = how meaningful/distinct/noticeable

Kamin (1965)

Kamin (1965) blocking experiment

rats are supposed to learn that the reduction of the noise would mean shock is on the way

• 80db - 70db + shock

• 80db - 60db + shock

• 80db – 50db + shock

• 80db – 45db + shock  

• 80db – 0db + shock - this group learned the fastest, bc it’s the biggest noticeable change

CS Decrease in background noise + US shock

familiarity/previous experience

• inhibits learning CR

• brings about latent inhibition

ex: in China red is good, lucky

• but if they’re in questrom and learning how to look at the stock market, the red line is BAD, but in your culture it’s good

latent inhibition

• pre-expose to CS repeatedly

• then pair CS w/ US

• learning is inhibited

• animals has learned that the CS is useless, has stopped paying attention

it has no meaning, and then all of it sudden it has a meaning

it used to have meaning, then all of a sudden there’s another meaning

• so familiarity is not good for learning

Garcia + Koelling in 1966

drank
split rats up 2 US

• electric shock

• lithium chloride injection (nausea)

audiovisiaul w/ pain

taste

how are these thigns related in real world? → enhances real learning

is there a biological relevance to humans

Quail + Rats

rats - poor vision, good smell/taste

quail - good vision, poor smell/taste

cs = blue or sour water

• blue = rats drank, quail didn’t

• sour = quail drank, rats didn’t

US = nausea drug

UR/CR = nausea

presence of extraneous stimuli

• Competition can occur when two cues (e.g., tone and light) appear together, acting as a compound stimulus

• The two cues compete with each other and neither produces as much learning as it would have if presented individually.

• Overshadowing occurs when a more salient cue within a compound acquires more of the share of attention and learning than the less salient cue.

• Conditioning occurs to 1 stimulus because it is more salient than the other stimulus present

overshadowing Kamin 1968

tested 3 separate stimuli as effective CS, all elicited CR

• light + shock

• 80db tone + shock

• 50dv tone + shock

tested 2 new groups w/ compound CS

• light & 80db tone + shock

  • light alone = strong CR

  • 80db mild CR

    • light overshadowed noise

• light & 50db tone + shock

  • light alone super strong CR

  • 50db no CR

    • light really overshadowed noise

    • bigger diff

blocking

one will overshadow the other bc 1 element has been previously conditioned

blocking Kamin 1968

control group

• trained to tone + light CS preceding shock US

• Afterward, both tone and light produced modest CRs (freezing).

Pre-trained group:

• Pre-trained with light CS preceding shock US

• Then same tone + light CS training as in the control group

• Afterward, light produced large CR and tone produced none.

Analogy

• Anne, the perfect stock analyst—an amazing find!

• Bob, the perfect stock analyst you meet one week after Anne—who cares! He’s redundant.

overshadow vs block

had no experience = overshadow

• one was more noticeable

• sushi

  • there’s something raw

  • but it tastes good

    • taste is better so it overshadows

have experience, but my previous with one was = blocking

• pasta w/ vegetables

  • hate vegetables, so i don’t try it

why is blocking strange?

conditioning without an explicit US

CS - US = cc happens

take it and use it as a substitute US

pair with smthg new

sensory preconditioning

2 CS, neutral stimuli

CS - US

CS2

• do you associate 2 things w/o explicit US

higher order conditioning

CS1 - US

CS2 - CS1

CS2?

You pair CS₂ with an already meaningful CS₁

step 1

• Friday night (CS₁) → fun times, friends, food at 5pm (US) → happiness (response)

After repetition:

• Friday night alone (CS₁) → makes you feel happy

Step 2: Higher-order (second-order) conditioning

Now you pair a new stimulus with the already conditioned one:

• CS₂ → CS₁

Example:

• Friday morning (CS₂) → reminds you of Friday night (CS₁)

After enough pairing:

• Friday morning (CS₂) → happiness (response)

sensory preconditioning

You pair CS₁ and CS₂ while both are still neutral, then add meaning later

• they all have the same meaning

  • fork, knife, plate → food is on the way
    •CS2-CS1

    •CS1 – US

    •CS2 -?
    
    
    Phase 1: Neutral + Neutral (no reward yet)

• CS₁ ↔ CS₂ (both mean nothing at first)

• Friday morning (CS₁) ↔ Friday night (CS₂)
  (just experiencing them together as part of the same day—no emotion yet tied to either)

Phase 2: Add the unconditioned stimulus

• CS₂ → US

Example:

• Friday night (CS₂) → fun, friends, food → happiness

Now:

• Friday night makes you feel happy

Phase 3: Test CS₁

Here’s the key:

• CS₁ (Friday morning) → happiness
  Even though it was never directly paired with the fun/reward