Welcome to the Second Part of the CourseTheoretical accounts of Pavlovian conditioningI) What makes an effective CS and US? What factors determine good conditioning?A) Contiguity: the closer two stimuli are in space and time, the stronger the association/conditioned response1) Delay conditioning is usually the strongest amount of conditioned responding2) Slightly less conditioning is achieved with trace conditioning3) Obviously very little evidence of conditioning with explicitly unpaired timing4) Simultaneous presentations (perfect contiguity) and backwards presentations generally present very little (or no) conditioned respondinga) Contiguity cannot be the sole factor (because perfect contiguity creates very little associations)B) Salience: more intense or noticeable stimuli condition more rapidly1) A larger outcome is valued more and attended to more by an individual2) True for both the CS and the USa) Examplesi) More food is valued more and will produce a conditioned response more quicklyii) A louder tone is attended to more and will produce a conditioned response more quickly (with fewer trials)3) More realistic CS conditions faster than less realistic CSa) Experiment example: quail matingi) An L shaped terrycloth object with either no head or a stuffed female quail head is presented to a male and paired with the presentation of a real, live female quailii) The terry-cloth object with the stuffed head creates conditioning fasterC) CS-US belongingness: a US can condition some CSs better than others, they just fit or belong together1) Paradigm example: rats are presented with a tube of sweet water, each time the rat takes a drink a light flashes and a tone soundsa) Sweet flavor is the CSb) There are two USs which follow the drink and light/tonei) Either a foot shock or induced illnessc) Question: can both fear cues and induced sickness be paired equally with flavors and audio/visual cues? NOi) The rats that were conditioned with sickness as the US display an aversion to the sweet water very little reaction to the audio/visual cuesii) The rats which were conditioned with shocking display a fear response to the audio/visual cues but no aversion to the sweet flavor of the waterd) Behavioral systemsi) Gut-defense system triggered by gastric illnessEvolutionarily advantageousii) Skin-defense system triggered by cutaneous painSounds and sights are condition-able to painful stimulie) Typical human fearsi) Snakes: when a baby or small child observes an adult displaying a fear or aversion to snakes, it picks up on that and is likely to acquire that fear itselff) Cook and Mineka experimenti) Monkey who is naïve to the CSs is presented with either a flower or a snake with a food dish behind itHow long does it take the individual to reach over the object for the food?ii) Demonstrator monkey who is fearful of either snakes or flowers is displayed to the naïve monkeyiii) Same test as beforeSnake fear was more quickly conditioned (hesitancy to reach over the snake) than fear of the flower (very similar measured response as the initial trial)D) Biological significance/Biological strength: a stimulus that commands a strong response can itself demand a response1) Second-order conditioninga) Phase 1: CS1 (light) is paired with a US (food) salivateb) Phase 2: CS1 (light) is paired with CS2 (tone)c) Test: After enough pairings the tone will elicit salivation2) Sensory preconditioninga) Phase 1: CS2 (tone) is paired with CS1 (light)  no real response besides orientationb) Phase 2: CS1 (light) is paired with US (food)  salivationc) Test: tone will elicit salivationThere is learning going on all the time through chains of associations of stimuli and responsesHow do we formally model accounts of Pavlovian conditioning?II) Two classes of modelA) Explain nature of CR1) Stimulus substitution: the CS becomes a substitute for the US; the form of the CR is similar to the form of the URa) There is a CS pathway of neural activation as well as a US pathway which generates a response; the two become connected such that the CS pathway comes to generate the response2) Homeostasis: special case of stimulus substitution (not all conditioned responses mimic a primary UR)a) US elicits two URs (opponent process theory)i) Primary UR moved system out of homeostasisii) Compensatory UR counteracts effects of primary UR, returns the system to homeostasisb) Form of the CR to the CS is like the compensatory UR (NOT BOTH)i) Example: fear conditioning and drug conditioning/toleranceFearPrimary UR= movement + increased heart rateCompensatory UR= freezing + lower HRCR= freezing + lower HRDrug conditioningPrimary UR= lower HR + lower BP + analgesiaCompensatory UR= increased HR + increased BP + sensitivity to painCR= increased HR & BP + sensitivity to painii) Evidence for opponent CRDrug users can overdose on a “typical” dose if taken in absence of drug-associated cues opponent process is not cued so does not “protect” the individualDrug cues can elicit CR, even in absence of the drugDeath can occur from under-doseOpponent process for heroin use: increased HR & BP can cause heart attack if elicited in the absence of the process with counteracts or is typically counteractedIII) More on the behavioral systems theory, Bill TimberlakeA) Proposed that conditioningB) Feeding behavior system1) Long delay CS: engages more general search behaviora) Will produce behaviors such as exploratory behavior2) Short delay CS: engages more focal search behaviorsa) Will produce behaviors such as goal tracking (going to the food location, grabbing the food)3) Example: another rat presented as the CS04/26/2012Welcome to the Second Part of the CourseTheoretical accounts of Pavlovian conditioningI) What makes an effective CS and US? What factors determine good conditioning?A) Contiguity: the closer two stimuli are in space and time, the stronger the association/conditioned response1) Delay conditioning is usually the strongest amount of conditioned responding2) Slightly less conditioning is achieved with trace conditioning3) Obviously very little evidence of conditioning with explicitly unpaired timing4) Simultaneous presentations (perfect contiguity) and backwards presentations generally present very little (or no) conditioned respondinga) Contiguity cannot be the sole factor (because perfect contiguity creates very little associations)B) Salience: more intense or noticeable stimuli condition more rapidly1) A larger outcome is