Learning, Conditioning, Motivation AS PDF

LEARNING AND CONDITIONING  Learning  Learning can be defined as a relatively permanent change in the brain that occurs due to experience.  Two basic kinds of learning:  Non-associative: involves learning about a single stimulus & includes habituation and sensitisation...

LEARNING AND CONDITIONING  Learning  Learning can be defined as a relatively permanent change in the brain that occurs due to experience.  Two basic kinds of learning:  Non-associative: involves learning about a single stimulus & includes habituation and sensitisation  Associative: more complex, involves learning about relationships among events  includes classical conditioning and instrumental conditioning  CLASSICAL CONDITIONING Learning process in which previously neutral stimulus becomes associated with another stimulus through repeated pairing with that stimulus Pavlov’s experiments  Pavlov’s research involved measuring dogs’ salivation in response to food (unconditioned stimulus, US) and found that the dogs began to salivate when they saw food dish and other stimuli associated with feeding time (conditioned stimulus, CS) integrated approach and look at how nature and nurture combine to shape human psychology 3 CLASSICAL CONDITIONING 4 CLASSICAL CONDITIONING Sunday, October 6, 20 (Pavlov,1904) 5 24  CLASSICAL CONDITIONING Pavlov’s experiments CONT. Drug tolerance: Refers to the decreased effect of a drug when taken repeatedly Regular intake of drug will trigger compensatory response of the body, e.g., caffeine raises blood pressure so compensatory response lowers it. If caffeine then taken under unusual circumstances, e.g., by injection, the compensatory response, which has been learned through classical conditioning, does not kick in and blood pressure raised. Shows mind- body connection. Acquisition – early stage of process where repeated pairings of CS & US take place – the learning curve 6  CLASSICAL CONDITIONING CONT. PAVLOV’S EXPERIMENTS: EXTINCTION – CR GRADUALLY DIMINISHES IF US OMITTED SPONTANEOUS RECOVERY – IF PARTICIPANT ALLOWED TO REST AND THEN PRESENTED ONLY CS AGAIN, CR REAPPEARS STIMULUS GENERALISATION – ADAPTIVE ABILITY TO REACT TO NEW STIMULUS WHICH IS SIMILAR TO FAMILIAR ONE BY GENERALISING RESPONSE STIMULUS DISCRIMINATION – ADAPTIVE ABILITY TO REACT TO DIFFERENCES IF NEGATIVE ASSOCIATION WITH ASPECT OF STIMULUS  Classical Conditioning…....Pavlov’s experiments Second-order conditioning – possible to condition participant to produce CR to novel stimulus by pairing novel stimulus to CS repeatedly even though novel stimulus never paired with US Conditioning and fear – CS leads to CR because it predicts occurrence of certain US – also true for emotional reactions. If particular CS reliably predicts pain, then absence of CS predicts pain not coming Classical Conditioning… Cognitive factors: Pavlov & others believed conditioning occurs if CS & US were temporally contiguous (occurred close together in time) Some argue that a critical factor behind classical conditioning is what is known – classical conditioning provides new knowledge of the relationship between two stimuli Research has shown a predictive relationship between CS & US more important than temporal contiguity or frequency of pairings 9 Classical Conditioning… Biological constraints To some extent, animals are “pre-programmed” to learn particular things in particular ways Learned taste aversion – a bad experience with certain food puts a person off that particular food but this conditioning does not entirely comply with classical conditioning – taste aversions common after just one bad experience (no repeated pairings), & CS-US interval is usually a very long (number of hours rather than immediate)  Instrumental (or Operant) Conditioning Operant Conditioning (aka instrumental conditioning) is a type of learning in which a behavior is strengthened (i.e., it will occur more frequently) when it is followed by reinforcement, and weakened (it will happen less frequently) when followed by punishment. When you are punished for doing something, you are less likely to do it again. Operant conditioning is based on a simple premise - that behavior is influenced by the consequences that follow. When you are reinforced for doing something, you are more likely to do it again. 11  Operant Conditioning Thorndike carried out experiments where animals engaged in trial- and-error learning where behavior strengthened if immediately followed by reward (law of effect). P.S. Humans often learn via trial-and-error too. P.S.S. Animals also reason. Elephant problem solving Mouse problem solving Sunday, October 6, 20 (THORNDIKE,1898) 12 24  Instrumental Conditioning… Skinner’s experiments Skinner’s experiments involved putting a hungry animal in a bare box except for a bar with a food dish under it. initial rate of pressing bar through exploration = baseline Acquisition & extinction: after the baseline is established, each time the bar is pressed, food is released which results in the frequent pressing of the bar If food stops being released, (Skinner,1948) similar extinction of Sunday, October 6, 20 14 24 Sunday, October 6, 20 15 24  Instrumental Conditioning…  Instrumental Conditioning… Skinner’s experiments Shaping: if the desired behavior is novel, there is a need to condition it by reinforcing only variations in behavior that deviate in the desired direction Conditioned reinforcer: almost any stimulus consistently paired with a primary reinforcer (which satisfies basic drives) Generalization and discrimination: organisms generalize learning can be curbed by discrimination training which is effective where discrimination stimulus clearly identifies cases for response or response suppression 17  Instrumental Conditioning… Skinner’s experiments: Schedules of reinforcement Ratio schedules: reinforcement depends on the number of responses an organism makes Fixed ratio schedule (FR): number of responses needed are fixed at a particular value whereas for Variable ratio schedule (VR): value for responses needed varies unpredictably Interval schedules: reinforcement is available only after certain time interval elapsed (& animal makes a response) fixed interval schedule (FI): organism reinforced for first response after time interval elapsed since last reinforcement 18 variable interval schedule (VI): interval duration  INSTRUMENTAL CONDITIONING… Skinner’s experiments Aversive conditioning: receiving a negative event immediately after a response results in response weakening or suppression Escape learning: a response terminates aversive event Avoidance learning: a response is learned to prevent an aversive event 19  Instrumental Conditioning… Cognitive factors Temporal contiguity is again an important factor for it occur Control: instrumental response is conditioned only when an organism interprets reinforcement as being controlled by its response Contingency: in classical conditioning, a behavior is contingent on a particular stimulus -- in instrumental conditioning, a behavior is contingent on a particular response Sunday, October 6, 20 20 24 Learning and Cognition LEARNED HOPELESSNESS - Martin Seligman - Dogs learning that they have no control over shocks, avoidance learning in the second stage made impossible – they learned that they were helpless - supports that instrumental conditioning occurs only when the organism perceives reinforcement as being under its control Sunday, October 6, 20 21 24  Biological constraints INSTRUMENTAL CONDITIONING…  As with classical conditioning, biology imposes constraints on what may be learned through instrumental conditioning.  Organisms find it easier and faster to learn a response if the behavior required makes sense on an ethological level Sunday, October 6, 20 22 24  THE DIFFERENCES BETWEEN CLASSICAL AND OPERANT CONDITIONING Is the behavior involuntary or voluntary?  Classical conditioning involves making an association between an involuntary response and a stimulus.  Operant conditioning is about making an association between a voluntary behavior and a consequence. Is there a reward or punishment?  Classical conditioning involves no direct incentives or enticements, thus it is passive on the part of the learner.  Operant conditioning requires the learner to actively participate and perform some type of action in order to be rewarded or punished. Sunday, October 6, 20 23 24 LEARNING AND COGNITION Observational learning Humans often learn without behavior being reinforced immediately through imitation & observational learning – copying behavior of others you deem successful. Nonhuman animals are also good at this. This does not mean they do not also reason. Sunday, October 6, 20 24 24 LEARNING AND COGNITION Bandura  Models inform us about consequences of behavior – so reinforcement is “vicarious”  He studied observational learning of aggressive behavior in children – found a learner needs to pay attention to a model’s behavior, remember, be able to reproduce behavior & be motivated to do so yet it still can occur readily, as was demonstrated in Bandura’s experiment Sunday, October 6, 20 (Bandura & Walters,1963) 25 24 Learning and Cognition… Prior beliefs With learning relationships between stimuli that are not perfectly predictive (on a biological level), people often draw from prior beliefs that constrain learning. Can you think of examples? Spurious Associations Non-existent, but plausible relationships detected by participants are referred to as spurious associations Sunday, October 6, 20 26 24 LEARNING & THE BRAIN Neural plasticity Ability of neural system to change through experience Change in the synapse is the neural basis of learning and the effect of this change is to make synapse more (or less) efficient Habituation and sensitization Types of non-associative learning Habituation: a behavioral response decreases over successive presentations of a stimulus Sensitization: a behavioral response increases during presentations of an intense stimulus 27  NEUROPLASTICITY Sunday, October 6, 20 28 24  LEARNING AND MOTIVATION Arousal Physiologically – arousal refers to the level of alertness of an organism Psychologically – arousal refers to the tension that can accompany different levels of arousal, ranging from calmness to excitement to anxiety Hebb proposed that organisms are motivated to maintain levels of arousal appropriate to the behavior in which it is engaged 29 MOTIVATION  Motivation is a condition that energizes behavior and gives it direction Arises from two sources:  internal drive factors (e.g., hunger)  external incentive factors (e.g., food) Incentives  Primary reinforcers: able to act as rewards independently of prior experience  Secondary reinforcers: able to act as rewards at least partly through learning about their relationship to other events  LEARNING AND MOTIVATION… From incentives to goals Early theorists focused on incentives (behavior motivated by expected reward) Not all behaviour can be motivated in this way our ability to anticipate long-term consequences of current behavior is an example of goal-oriented behaviour Intrinsic motivation and learning The cognitive approach to the study of motivation emphasizes individuals understanding and interpretation of their actions 31  LEARNING AND MOTIVATION… Intrinsic motivation and learning Intrinsically motivated: motivated by internal feelings Extrinsically motivated: motivated by anticipated external rewards Intrinsically motivated individuals: more persistent at a task memory of complex concepts is better handle complex material in more creative ways External rewards can harm intrinsic motivation Sunday, October 6, 20 32 24 Into which category – intrinsic or extrinsic – do the following statements fit? I want others to think I’m attractive. I want to figure out how the brain works. My boyfriend thinks smart girls aren’t as sexy, so I’ll play dumb. I’m so curious about why those plants grow that way. I can’t wait to dig into that Chopin piece! If I don’t get my homework done, she’ll fail me! That trophy will look good on my shelf! It feels great hooking into the top spin with my backhand! Sunday, October 6, 20 33 24  T H A N K YO U ! QUESTIONS Sunday, October 6, 20 34 24