PSY 402Problems with Rescorla-Wagner4.7 (A) Mackintosh-Turner experiment; (B) Results of exposure to LN-shock trialsThe Mackintosh ModelCriticisms of the Mackintosh Model4.8 (A) A Hall and Pearce experiment design; (B) Results of conditioning during Phase 2Pearce Hall Model4.9 A rat orienting toward a light CS (Part 1)4.9 Orienting to the light CS with a US pairing (Part 2)Memory and Learning4.10 The standard model of cognition or information processingKinds of PrimingPriming of the USPriming of the CS4.11 (A) Timeline and; (B) Results: Priming effects associated with aversion to vinegarChanging the ContextDoes Priming Explain Habituation?4.12 Whitlow's Experiment: Effects of self-generated priming on habituation (Part 1)4.12 Whitlow's Experiment: Effects of self-generated priming on habituation (Part 2)Connectionist Views of Memory4.13 Memory nodes may be associated with one anotherWagner’s SOP ModelHow the Model WorksSOP Explains Timing Effects4.14 Activation of a memory node in SOP theory (Part 1)4.14 Activation of a memory node in SOP theory (Part 2)4.15 Conditions depict delay conditioning (Part 1)4.15 Conditions depict trace conditioning (Part 2)4.15 Conditions depict backward conditioning (Part 3)Affective Extension of SOP (AESOP)4.16 AESOP envisions parallel associations between CS and sensory and emotive US nodesPearce’s Configural Theory4.17 Organisms might learn about elemental or configural CS nodesTypes of ConfigurationsElemental TheoriesSOP’s Explanation4.18 (A) Design and; (B) Results of the experiment by Brandon, Vogel, & WagnerPSY 402Theories of LearningChapter 4 – Theories of ConditioningProblems with Rescorla-Wagner It predicts that presenting an inhibitory CS without the UCS should lead to extinction, but it doesn’t. The model cannot account for latent inhibition (preexposure to the CS). Mackintosh demonstrated that animals learn to ignore redundant stimuli – the model doesn’t predict this learning.4.7 (A) Mackintosh-Turner experiment; (B) Results of exposure to LN-shock trialsMore learningLess learningThe Mackintosh Model Mackintosh proposed that the amount of learning depends on how much attention the animal pays to the CS. The attention to the CS is the α term in the Rescorla-Wagner model. Alpha increases when the CS is the best predictor and conditioning occurs to the best predictor of the UCS.Criticisms of the Mackintosh Model The model does a good job of explaining latent inhibition and its own criticisms of Rescorla-Wagner, but other problems arose. While attention is important, it doesn’t necessarily increase when a CS becomes the best predictor. Hall & Pearce showed that preexposure to a tone that was a good predictor of weak shock didn’t help learning when a stronger shock was used.4.8 (A) A Hall and Pearce experiment design; (B) Results of conditioning during Phase 2More learningLess learningGroup 1 should have done better, but didn’tPearce Hall Model Animals don’t waste attention on stimuli whose meaning is already well understood. Instead, they devote attention to understanding new stimuli. For their model, the value of alpha depends on how surprising the UCS was on the previous trial. If the UCS is surprising, the CS is not well understood. Alpha is high when this occurs.4.9 A rat orienting toward a light CS (Part 1)This is orienting behavior – the rat is paying attention to the light4.9 Orienting to the light CS with a US pairing (Part 2)Rats paid more attention to the light when its meaning was unclear (Partial condition)Memory and Learning Wagner extended the Rescorla-Wagner model to incorporate ideas about memory. A surprising event is an event you are not already thinking about. A surprising event gets more processing and thus is more likely to become part of memory. Priming occurs when an event is already present in short-term memory. Priming reduces surprise.4.10 The standard model of cognition or information processingKinds of Priming Self-generated priming – this occurs when an event primes itself in short-term memory. Retrieval-generated priming – this occurs when a retrieval cue calls an item out of long-term memory. Presenting a CS retrieves the UCS associated with it. The CS is thus a retrieval cue for the UCS.Priming of the US Ideas about priming provide new explanations for some learning phenomena. Presenting the US before a CS-UCS pairing interferes with learning (pre-exposure to the US). Priming explains this – the US is already present in memory so it is not surprising, and the retrieval cue (CS-US association) is not needed. Learning improves when an intervening stimulus (click & vibration) replaces the US in memory.Priming of the CS The revised Rescorla-Wagner model suggests that the surprisingness of the CS is as important as the surprisingness of the UCS. Latent inhibition occurs because the CS is not surprising (due to pre-exposure to the CS). Priming of vinegar (the CS) prevents learning, but exposure to vanilla in between enhances learning by replacing vinegar in memory.4.11 (A) Timeline and; (B) Results: Priming effects associated with aversion to vinegarNo priming (preexposure)VinegarVinegar + VanillaMost learningChanging the Context Due to the long time lapses (24 hrs typically), the CS cannot remain in short-term memory. The context is the cue that retrieves the CS. This is retrieval-generated priming When the context is changed, there is no pre-exposure effect and learning is normal. When CS preexposure and conditioning occur in different contexts, there is no latent inhibition.Does Priming Explain Habituation? If the response to a stimulus results from its surprisingness, perhaps habituation occurs when the surprise goes away with exposure. Whitlow studied rabbits presented with the same or different tones. Habituation occurred, disrupted by a distractor. However, habituation transferred to new contexts – but latent inhibition does not.4.12 Whitlow's Experiment: Effects of self-generated priming on habituation (Part 1)Note the difference4.12 Whitlow's Experiment: Effects of self-generated priming on habituation (Part 2)Distractor StimulusThe effect goes awayConnectionist Views of Memory Long-term memory consists of associations between representations. Nodes connected by arrows The US and CS’s and context are all nodes. When a CS
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