PSY 301 1st Edition Lecture 18 Outline of Last Lecture I Positive Psychology II Cognitive Theories III Key cognitive Concepts Outline of Current Lecture I Learning II Classical Conditioning III Biological Bases of Learning IV The Unconditioned Pair V Garcia Study Current Lecture Learning a relatively long lasting change in thought or behavior produced by environmental events 1 refers to actual changes in the person 2 performance new behaviors produced by these changes Two types of conditioning 1 classical conditioning learning new connections between stimuli 2 operant conditioning learning new connections between acts and their consequences Learning to associate one stimulus with another Learning to associate a response with a consequence Assumes that basic laws of learning exist 1 complex learning involves combinations of these simpler laws 2 allows for study of animals and simple situations Classical Conditioning Classical Conditioning the processes involved when an organism learns to associate two events First discovered by Ivan Pavlov in studying salivation in dogs Before conditioning Food is presented unconditioned stimulus US The dog salivates to food unconditioned response UR A tone is sounded neutral stimulus Dog does not salivate no response During Conditioning The tone is sounded Food is presented Dog salivates to food experimental trial tone food salivation After conditioning after many trials the tone and the food becomes associated and the dog will salivate to the tone alone Tone is presented conditioned stimulus CS Dog salivates conditioned response CR Biological Bases of Learning Learning depends upon neural plasticity the capacity for neurons to change the way in which they function in response to experience Plasticity always involves changes at the synapse changes on the ways in which neurons communicate with each other Learning involves one of three kinds of changes at the synapse 1 presynaptic facilitation after learning some neurons send out a stronger stimulus 2 long term potentiation LTP after learning some neurons become more sensitive to the signals they have been receiving all along 3 new synapses after learning some neurons form entirely new connection with other neurons The unconditioned unlearned pair Unconditioned stimulus UC a stimulus which innately produces the unconditioned response Unconditioned response UR a response the innately occurs to the UCS Conditioned stimulus CS a stimulus which is initially neutral it never naturally produces the conditioned response but which comes to produce the conditioned response after being associated with the US Conditioned response CR a response that is made naturally to the UCS by never to the CS the learned response to the CS Explanation 1 food naturally causes the dog to salivate 2 the bell becomes associated with the food 3 the dog learns that the bell predicts the coming of food 4 the dog salivates to the bell The CS serves as a signal that the UCS is coming 1 the CS can be used to predict the coming of the US 2 when the CS doesn t occur it predicts the absence of the US a when the UCS is aversive the absence of the CS can serve as a safety signal 3 these contingencies don t have to be perfect to produce conditioning but the occurrence of the UCS must be more probable after the CS Some contingencies are hard to learn 1 overshadowing a very dominant component of a complex stimulus will be so strong that it becomes the only CS 2 blocking difficult to attach a new CS to a well established CS UCS relationship Acquisition is the initial learning in which an association is formed between a neutral stimulus and an unconditioned stimulus 1 more pairings of the CS and the US produce a stronger CR a these pairings reinforce the UC CS relationship b called reinforced trials Extinction if the CS is repeatedly presented without the UC the CR will eventually be eliminated 1 a CR can easily be reconditioned by reintroducing the US 2 an extinguished CR can be spontaneously recovered Stimulus generalization the CR will be made to stimuli that are similar to the CS 1 CR is weaker than to the CS 2 The more similar the CS and the new stimulus the stronger the CR 3 generalization is progressive Stimulus discrimination making the CR to the CS and not to a similar unreinforced stimulus Higher order conditioning using a well established US CS relationship to produce new conditioning 1 The previous US becomes the CS in the new conditioning Biological constraints on learning 1 different kinds of animals are biologically prepared to learn different kinds of associations with different degrees of difficulty 2 taste aversions an animals learns to avoid food with a certain taste because it is associated with bad experiences Garcia study Part 1 1 Thirsty rat licks a water tube and 2 things happen receives sugar water and turns on a light tone combination 2 After drinking all rats have an aversive experience 1 A half the rats get violently sick 2 B half the rats are shocked through their feet Part 2 1 Rats are water deprived again 2 Allowed to drink in one of 2 situations A half drink sugar water but without a l light tone sound B half drink plain water but with the light tone sound Which rats will drink Rats who were made ill 1 will NOT drink sugar water without light tone 2 WILL drink plain water with light tone Rats who were shocked 1 WILL drink sugar water without light tone 2 will NOT drink plain water With light tone
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