PSY 402Classical vs. InstrumentalPavlov’s Conditioned ReflexPolitical Classical ConditioningObama TooCaught up in the Moment?Conditioning ProcessesWhat is Learned?Conditioning Situations3.7 Autoshaping in pigeons (Part 1)3.7 Results of autoshaping tests in pigeons (Part 2)3.5 Design of eyeblink conditioning experiment in rabbits (Part 1)3.5 Results of eyeblink conditioning experiment in rabbits (Part 2)Conditioned Emotional ResponsesFear conditioning3.6 Conditioned suppression in rats (Part 1)Suppression Ratio3.6 Conditioned suppression in rats (Part 2)Flavor Aversion LearningAcquired Changes in ResponseFactors Affecting ConditioningStimulus Presentation Paradigms3.8 Different ways to present CS and US in timeTemporal ConditioningMassed vs Spaced Trials3.9 Trial spacing in Pavlovian conditioningImportance of ContiguityImportance of PredictivenessPreparedness Affects LearningHumans Show PreparednessStimulus Intensity (Strength)Pseudo-conditioning3.10 Bernstein’s experiment on taste aversion learningConditioning and AddictionsPSY 402Theories of LearningChapter 4 – Nuts and Bolts of Conditioning(Mechanisms of Classical Conditioning)Classical vs. Instrumental The modern view is that these two types of learning involve similar learning processes, but differ in the following ways.1. In Classical conditioning, two stimuli are associated with each other but in Instrumental conditioning, a stimulus and a response are associated.2. In Classical conditioning, the response is a reflex or involuntary action but in Instrumental conditioning, the response is a voluntary, freely emitted behavior.Pavlov’s Conditioned Reflex Conditioning -- a stimulus that initially produces no response can acquire the ability to produce one. Learning occurs through pairing in time and place of one stimulus with another stimulus that produces an involuntary response.Political Classical ConditioningObama TooCaught up in the Moment?Conditioning Processes Stimulus generalization – stimuli like the CS become able to evoke the conditioned response. Extinction – if the UCS and CS are not paired, the CS loses its ability to produce a conditioned response. Spontaneous recovery – an extinguished CS briefly returns but quickly goes away again.What is Learned? Pavlov believed the association was between the two stimuli (tone and meat powder), not between the tone and salivation.Stimulus substitutionEither is possibleConditioning Situations Sign-tracking (autoshaping) – animals must recognize signs of food (UCS) and respond (UCR). Pigeons pecking at key. This is a UCR, not an operant response, because pecking behavior is specific to the food stimulus. Eyeblink conditioning UCR is rapid, CR is slow. Many trials are needed (100 pairings)3.7 Autoshaping in pigeons (Part 1)3.7 Results of autoshaping tests in pigeons (Part 2)3.5 Design of eyeblink conditioning experiment in rabbits (Part 1)3.5 Results of eyeblink conditioning experiment in rabbits (Part 2)Conditioned Emotional Responses Fear is an anticipatory pain response based on past experience. Fear is conditioned (becomes a CR) whenever a CS is associated with an aversive (painful or undesirable) event. Fear motivates two responses: Escape (when pain is present) Avoidance (when pain is about to happen)Fear conditioning Avoidance is not a good measure of fear. Suppression of an operant behavior occurs with a feared stimulus. First – an operant behavior is learned (bar press). Second – a CS is paired with an aversive UCS (light with shock). Third – the CS is presented in the operant chamber and the effect on operant responding is measured.3.6 Conditioned suppression in rats (Part 1)Suppression RatioDuring CSSuppression Ratio =During CS + Without CS The amount of time during and without the CS is equal. The more fear, the lower the suppression ratio. Ratios typically fall between 0 and .5 This will be on the midterm3.6 Conditioned suppression in rats (Part 2)Flavor Aversion Learning Garcia – rats will not drink water with saccharin if they get ill after drinking. Significant avoidance occurs after just one trial. Human food aversions are related to illness (89% of the time). Even if illness occurs hours later it is linked to the previous meal. Not cognitive – you can know the food is not to blame and still feel an aversion to it.Acquired Changes in Response Habituation – response to a repeated stimulus decreases with non-threat experience. Sensitization – response to a variety of stimuli increases with a single threat experience. Examples: Ingestional neophobia, fear of new food Rats orient less toward light, startle decreases Chicks are less frightened by shadows flying overhead with repeated exposure.Factors Affecting Conditioning Timing – how closely in time are the CS and UCS, and which occurs first. Novelty of the CS and UCS. Intensity (strength) of the CS and UCS. Consistency of the pairing between the CS and UCS. If one or the other appears alone then conditioning is weakened.Stimulus Presentation Paradigms Delayed conditioning – the CS onset precedes the UCS onset. Trace conditioning – the CS starts and ends before the UCS onset. Simultaneous conditioning – the CS and UCS occur together. Backward conditioning – the UCS starts and ends before the CS onset. These paradigms will be on the midterm3.8 Different ways to present CS and US in timeThis works bestThis doesn’t work at allThis isn’t as good as delayedThe longer the gap (trace interval) the worse this worksTemporal Conditioning The UCS occurs at regular intervals in time. Nominally, no CS is present, but aspects of the context in which the UCS occurs become conditioned to it. Examples: Waking up just before the alarm goes off. Your dog knows when you will come home. Getting sleepy right around bedtime.Massed vs Spaced Trials Better learning occurs when trials are spaced out over time (spaced), rather than bunched together (massed). Memory consolidation or rehearsal may be needed between trials. The ratio between the exposure to the CS and the time in-between is the important factor. If both are the same duration, learning is weaker.3.9 Trial spacing in Pavlovian conditioningThis doesn’t work as wellThis works bestImportance of Contiguity “Wait ‘til your father gets home”
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