Exam 2 Study Guide Topic Pavlovian Conditioning Continued Experiments T1 T2 Model o T1 Training process o T2 The post training test Experimental and control group will be treated the same Want to show that experimental group shows a response T1 T2 can be intersected control group does not Aka going back to T1 after T2 Typical Classical Conditioning Procedures o How do we present the stimuli during training T1 o How do we measure the CR T2 Common Procedures o Delay Conditioning between o Trace Conditioning CS then US There is a little delay between onset of CS and US Inter stimulus interval Time can vary Want no chance of other stimulus intervening coming in CS turns off a little before US turns on This gap in time is called the trace interval Inter stimulus interval is still the time between the onset of CS and US Less Effective Procedures o Simultaneous Conditioning CS US perfectly overlap Not as effective as delay or trace Losing predictive value o Backward Conditioning US presented before CS No predictive power since CS is after Can still get learning though so shouldn t use as CS could stand for a safety signal I have some safe time now control Ex foot shock US then sound CS sound tells the rat How do we measure CR o Why no US in T2 Control They will definitely respond to US which ruins ability to detect the CS o Did the behavior change because the subject learned an o What are the factors we want to control for in classical association between the CS and US conditioning experiments All things that could potentially change behavior and aren t learning Age development extraneous stimuli physiologic Other kinds of learning most importantly sensitization state emotional state etc Ex Foot shock could put animal in elevated state of arousal which could make her start responding to the CS Need control group in order to account for this How do we control for these factors o Present CS alone o Present US alone o Ideal No Not a good control They must be exposed to US No Must be exposed to CS Same number of CS and US exposures but no association How Don t do delay conditioning Make sure there s enough time between stimuli Time varies For example Shock 3 5 minutes Eye blink 30 seconds Conditioned taste aversion a couple days o Random Control Procedure Both CS and US are presented the same number of times Difference Same probability of occurrence during CS and Computer may generate a random sequence of times for as for the experimental group during inter trial interval appearance overlap Since it s random CS and US might sometimes o Problems with Random Control Procedure Associative learning can occur during this procedure Random presentation sometimes they will coincide You may conclude the experiment group didn t have learning when they did but the control group did as well o Better Choice 1 Explicitly Unpaired Control CS US always presented separately How long does the inter stimulus interval have to be Far enough apart for there not to be association Variation CS US presented during different Controlling for sessions CS US pairing vs simple exposure to CS or US Fatigue sensory adaptation sensitization Baseline response rate Individual differences if subjects have been randomly assigned Predictions If we have true associative learning Increased CR to CS in experimental group No change in control group Increased response in both groups If we have sensitization o Better Choice 2 Discriminative Control Uses 2 CSs CS paired with US CS never paired with US CS and CS trials usually presented in random Every animal will experience both order CS US right away CS later CS US CS later Can even present stimuli on different days Experiment using Discriminative Control CSs Tone light Group 1 gets tone as CS light as CS Group 2 gets light as CS tone as CS US Food CR Orienting to tone light E g jerking head looking at speaker looking at light Controlling for CS US pairing vs simple exposure to CS or US Individual differences Differences in the quality of the CS Predictions If associative learning CS elicits CR CS does not elicit CR Regardless of group If CS or US caused sensitization Both CS and CS elicit CR Remember if learning happened you should NOT respond to CS If rats prefer one stimulus over the other E g tone elicits CR whether it is the CS or CS If stimulus elicits response no matter what Maybe the CS is actually a US not a good stimulus to use o What s the Best Control Depends on specific requirements of each individual Take into account the relative confounding factors experiment Stimulus factors relationships What makes a good CS What makes a good US How does the relationship between CS and US affect associative learning o CS US intensity salience More intense CS or US more vigorous CR Control for sensitization is important Stimulus salience Significance or noticeability How important it is in your life Emotional state motivational state physiologic state past experiences etc can all determine how salient something is How attention getting is the stimulus Modulated by Intensity High intensity makes a stimulus salient Something that isn t very intense can also be salient E g if you re hungry a small piece of food can be salient Biological relevance o Does Novelty Familiarity Matter Latent Inhibition Decreased effectiveness of a CS due to prior Aka CS pre exposure effect exposure The more experience you have with a CS less likely to enter new association the weaker it will be Inhibits new learning in the future Latent something you can t see in the moment but Ex happens later You have a lot of experience with a certain food one day you get sick after eating harder to develop CTA CS 10 sucrose solution Experimental group pre exposed PE Control group non pre exposed NPE US Lithium Chloride causes nausea DV Ingestion of sucrose After experiment given a bottle of sucrose and a Results IV What happens in pre training bottle of water See which the rat prefers Significant difference between NPE and NE However PE is only at 30 so they don t prefer sucrose either but more so than NPE Example CTA Effects in humans Ice Cream Study Bernstein 1978 Children undergoing chemotherapy Eat maple and black walnut ice cream 5 months later choice test play game or eat ice Before chemo or a day with no chemo cream Non paired chose ice cream Chemo paired much less interested in ice cream Scapegoat Taste Use novel taste as a CS for CTA Prevent development of CTA to commonly eaten foods Bring in novel taste