What is classical conditioning? Classical Conditioning Learning & Memory Arlo Clark-Foos Learning to associate previously neutral stimuli with the subsequent events. Howard Eichenbaum s Thanksgiving Pavlov s psychic secretion Are you conditioned? Ivan Pavlov Some examples of every day conditioning Holiday Traditions Food Associations Fears Superstitions Habits Skills? How are digestive fluids controlled? Historical view Pavlov s view Pavlov s Original Experiment 1
Pavlov s Experiments Stimuli and Responses Psychic Secretion Specialized procedure for introducing food Claude Bernard s psychic secretion in horses Pavlov s psychic secretion was unreliable but Pavlov Museum, Ryazan, Russia This is appetitive conditioning. What is an example of aversive conditioning? Conditioned Emotional Response Slapping and Blinking in the Name of Research Ernest Hilgard Clark Hull Estes & Skinner Appetitive Electromyography (EMG) Photo Sensors Very well studied (Dudai, Jan, Byers, Quinn, & Benzer, 1976) (Domjan, Lyons, North, & Bruell, 1986) 2
Forward Conditioning 10/5/2017 Rabbit Eyeblink Conditioning It gets more complicated reactive Similarity among species Tolerance, compensatory responses, and homeostasis Stimulus Timing and Presentation Contemporaneous Presentation Not spaced too far apart in time Is there an ideal spacing? Order and Consistency Reliable relationship/expectation predictive Conditioning Procedures Learning Not to Respond Interstimulus Intertrial Interval Interval Conditioned Inhibition: Decrease in CR in response to CS. Need Baseline CS+ 1(Tone) US CS- 2(Light) CS 1? CS 2? CS 1 + CS 2 CRs diminish over time as CSinhibits CS+ Baseline 3
Transfer of Learning Context as CS Generalization CS (Tone,1200mHz) US CS 800mHz CR CS 1200mHz Max CR CS 1600mHz CR Penick & Solomon (1991) Eyeblink conditioning in rats Hippocampal Lesions Discrimination CS (Tone,300mHz) CS (Tone,500mHz) US CS (Tone,800mHz) CS 300mHz CS 500mHz CR CS 800mHz Transfer Appropriate Processing & Encoding Specificity What is being conditioned? S-S or S-R Association? How is it learned and what is the nature of the association? Stimulus Substitution Theory (Pavlov) Definition (S-R Association) US, CS, and Response centers in the brain US S-S Association Response CS S-R Association Problem: a CR is not a UR CR eyeblink is often more gradual and less complete 4
Rescorla (1973) After Conditioning US Devaluation Lever Reward Conditioned Suppression (Light/CS + Loud Noise/US) Habituate Noise Lever + Light? After learning, what happens when you present the CS alone? US Less CR after US devaluation. S-S Association S-S Association CS S-R Association Response Extinction What happens in extinction? Extinction = Forgetting? What do we (researchers) see? No CR = Forgetting? Excitatory and Inhibitory Associations (Pavlov) CC Extinction Spontaneous Recovery Pavlov: Inhibitory connections are weak, fade Alt. Theory: Attention/Interest in CS (habituation?) Human eyeblink conditioning and the reduction in responses during extinction. Human eyeblink conditioning and the reduction in responses during extinction. 5
Extinction = Forgetting? Compound Conditioning Disinhibition Surprising, typically arousing, new stimulus Return of CR (akin to sensitization) Rapid Reacquisition Retraining vs. Original Conditioning Something is retained Context, Multiple Cues Extinction: respond and don t respond Overshadowing Salience Extinction is NOT Forgetting Error Correction Rescorla-Wagner (1972) Problems with Aristotle s contiguity Informational value of cues Kamin s (1969) Compound conditioning Learning on Trains Contiguity is not enough Competition for associative strength Prediction Error Positive vs. Negative prediction errors Error-correction learning 6
R-W in Humans Modelling Conditioning Error Correction in Human Category Learning Bower & Trabasso, 1964 Informational value of dot Associative Weights Connectionist Models (e.g., McClelland & Rumelhart) Pay Attention! Properties of C Conditioning Exposure to CS alone retards later learning Attention to stimuli Latent inhibition Lubow & Moore (1959) Sheep and Goats Where is the surprise? US Modulation Theory Prediction error (Rescorla & Wagner, 1972) CS Modulation Theory Attention to stimuli (Mackintosh, 1975) It takes time 4-5 mo., no eyeblink conditioning in first block but exposure necessary for later learning. Other Factors Intensity of CS-US Timing, ISI Ivkovich et al., 1999 7
Intensity of CS-US Timing, ISI Faster and More effective US Intensity Maintained US Intensity Decreased Timing is critical! Ideal ISI for rapid learning Humans = Animals Pavlov observed no CRs with Backward Conditioning: CS does not predict US. Animals must be learning association AND temporal contiguity Taste Aversion (Garcia Effect) Neural Basis in Mammals Temporal Contiguity Food poisoning after a date Belongingness: CS-US pairings. Tone + Food Shock or Poison (Garcia & Koelling, 1966) Neurological basis: gustatory cortex Coyotes (Gustavson et al., 1974) Cerebellum Purkinje cells Inhibitory connection to interpositus nucleus Interpositus nucleus Brain Stem CR output pathway Error correction Pontine nuclei (CS) Specialized sensory processing Inferior Olive (US) Activates interpositus nucleus and Purkinje cells 8
Neural Bases of CC Cerebellum Electrical activity A simpler diagram of Rabbit eyeblink conditioning Purkinje cells Stimulating the inferior olive Even specific tones, lights, etc. Substitute for actual US CC impaired after damage CS Modulation Back to Aplysia Latent inhibition not explained by RW Mackintosh (1975) Salience of Sensory cues Hippocampus Animals without do NOT show latent inhibition 9
CC in Aplysia Neural Bases of CC 1. Aplysia and Eric Kandel In the long run, it s all just LTP Proteins Addiction and Tolerance Two routes to long lasting memory Activate CREB-1 Synaptic growth Deactivate CREB-2 Rapid learning Homeostasis and compensatory responses Environmental cues as CS Reducing reliance on drugs? + + 10