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Chapter 5

Chapter 5. Learning and Behaviour. The Big Picture. This chapter focuses on the manner in which we learn to behave in certain ways given certain environmental conditions The emphasis will be primarily on stimulus-response mappings, and how they are formed

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Chapter 5

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  1. Chapter 5 Learning and Behaviour

  2. The Big Picture This chapter focuses on the manner in which we learn to behave in certain ways given certain environmental conditions The emphasis will be primarily on stimulus-response mappings, and how they are formed There will be very little discussion of cognitive states or processes … which contrasts quite strongly with the methods that are more popular today Chapter 5 - Learning and Behaviour

  3. The Starting Place - UCSs & UCRs We come equipped with many stimulus response mappings that simply reflect our machinery in action … for examples: > When we put food in our mouths, digestive processes are initiated > If a projectile is coming at our face we close our eyes, duck our heads, raise our hands, and sometimes hold our breath These associations are the produce of evolution (or creation) and the components of them are labeled as unconditioned stimuli (UCS) and unconditioned responses (UCR) > Food (UCS) -> Digestive Process (UCR) Chapter 5 - Learning and Behaviour

  4. Habituation - Weakening the SR Mapping The occurrence of some novel stimulus in the environment (UCS) tends to lead to a startle response (UCR). However, if the stimulus occurs repeatedly without any positive of negative consequence, the startle response stops occurring. This is a process called habituation … as examples of it consider: (1) Those weird house noises you no longer hear (2) Airplanes at my old place Basically, if the UCR proves itself unnecessary in the presence of some UCS … the UCR may occur less and less Chapter 5 - Learning and Behaviour

  5. Classical Conditioning - The Extensionof SR Mappings to New Stimuli In 1904, a Russian scientist named Ivan Pavlov stumbled across an interesting phenomenon while studying how the canine digestive system worked. This phenomenon has come to be called classical conditioning, and it explains how new stimuli can come to be associated with certain behavioural responses. Pavlov’s is now known as one of the most influential figures in psychology, and his experiments helped to start the wave of behaviourism that ruled psychology for many years. Chapter 5 - Learning and Behaviour

  6. Pavlov’s Experiment - Baseline At the beginning of the experiment, if a bell was rung near the dog it did not salivate. Chapter 5 - Learning and Behaviour

  7. Pavlov’s Experiment - Baseline However, if food (UCS) was presented to the dog, it would salivate (UCR) UCS UCR Chapter 5 - Learning and Behaviour

  8. Pavlov’s Experiment - Conditioning Over a number of trials, the bell the CS or conditioned stimulus is rung just before the food is delivered UCS CS UCR Chapter 5 - Learning and Behaviour

  9. Pavlov’s Experiment - Testing After a number of conditioning trials, if the CS is presented alone, it will typically lead to a conditioned response … which is similar in form, if not degree, to the unconditioned stimulus CS CR Chapter 5 - Learning and Behaviour

  10. Classical Conditioning Overview In order for classical conditioning to be effective, the UCS must reliably follow the CS. If this association is not strong throughout the conditioning phase, the learning will be weak. If the association between the CS and UCS is terminated after conditioning … the CR will eventually not occur in response to the CS - a process called extinction. However, an extinct CS-CR mapping can become active again quickly if the CS/UCS association again becomes strong again - a process called spontaneous recovery. Chapter 5 - Learning and Behaviour

  11. Operant Conditioning The term “operant” refers to the notion that humans learn from operating on their environment. We behave, then note the consequences and use them to modulate future behaviour. The famous cat torturer Edward Thorndike was one of the first to study operant conditioning. Early on, his research focused on “learning by trial and accidental success” Through this, he formed the Law of Effect which states that a behaviour that is followed by a positive consequence will tend to be repeated --- note similarity to evolution theory. Chapter 5 - Learning and Behaviour

  12. Behavior Analysis & B. F. Skinner Skinner strongly championed the experimental study of the Law of Effect, and he made strong claims to its application to human behaviour -- Walden Two He invented a number of devises for studying operant conditioning … the most famous being the operant chamber or “Skinner Box” This device allows the experimenter to control a number of environmental stimuli, and allows him to deliver both rewards (most typical) or punishment. Chapter 5 - Learning and Behaviour

  13. Basic Skinner Box Lights Speaker Lever Floor the can be electrified (punishment) Food Hopper (reward) Chapter 5 - Learning and Behaviour

  14. Measuring Behaviour Behaviour is often measured in terms of rate of responding (i.e., number of responses within some period of time) Skinner came up with a response recorder apparatus that allowed him to record each response over time. This device is called a cumulative recorder because it keeps track of the total number of responses over time. Thus, the effects of variables on the response rate could be measured allowing one to see if certain variables strengthen (i.e. increase) the response of interest, or weaken (i.e., decrease) the response of interest. Chapter 5 - Learning and Behaviour

  15. Graph from a Cumulative Recorder Chapter 5 - Learning and Behaviour

  16. Notion of a Three-Term Contingency Skinner described any behavioural event in terms of three parts: (1) The preceding event, which usual involves the presentation of a discriminative stimulus (2) The behavioural response to the discriminative stimulus (3) The following event, which represents the consequence of our behaviour e.g., training killer whales at Sea World Chapter 5 - Learning and Behaviour

  17. Ways of Altering Behaviour Positive Reinforcement - A given behaviour tends to increase in frequency if it is followed by an appetitive (desirable) stimulus. Negative Reinforcement - A given behaviour also tends to increase in frequency if it is reliably followed by the termination of an aversive (undesirable) stimulus. Punishment - A given behaviour tends to decrease in frequency if it is reliably followed by an aversive stimulus Response Cost - A given behaviour tends to decrease in frequency if it is reliably followed by the termination of an aversive stimulus Extinction - The reduction of a behaviour if it is not reinforced Chapter 5 - Learning and Behaviour

  18. Shaping Behaviours Shaping - Teaching an organism to learn a new behaviour through successive approximation. In the case of a Dolphin learning a new trick, this involves first rewarding behaviours that are very generally consistent with the trick … then altering the criterion for reward, making it more and more specific to the trick What about a prof learning Karate, or someone learning a new language? Chapter 5 - Learning and Behaviour

  19. Intermittent Reinforcement Refers to situations in which not every occurrence of a response is reinforced. This leads to an issue termed schedule of reinforcement Fixed-ratio: An animal can be rewarded after making some set number of responses - leads to behaviour bursts Variable-ratio: Same as above except it is delivered on average every so many behaviours - leads to rapid and constant responding (slot machines) Fixed Interval: Reinforcers can be deliver after a set period of time has passed - leads to responding just before Variable Interval: Same as above except random - leads to slow, steady responding Chapter 5 - Learning and Behaviour

  20. Resistance to Extinction A behavior that has been learned on an intermittent reinforcement schedule is much more resistant to extinction that one that had been rewarded more consistently The higher the ratio of the reinforcement, the higher the resistance What does all this suggest about gambling? Chapter 5 - Learning and Behaviour

  21. Generalization and Discrimination In classical conditioning, generalization refers to the extent to which a stimulus similar to the CS can elicit the CR. In operant conditioning, generalization refers to the extent to which a stimulus similar to the discriminative stimulus elicits a response. Animals can learn to both generalize, and simultaneously, to discriminate. In a sense, they learn to categorize stimuli into those that should be responded to, and those that are not worth the effort. > Pigeon learning human concept > Why are weddings so stressful! Chapter 5 - Learning and Behaviour

  22. The Importance of Secondary Reinforcers Most operant conditioning experiments use primary reinforcers during learning (e.g. food, pain). However, much of our learning in the real world is more affected by secondary reinforcers (e.g., money, smiles, “pats on the back”, compliments). These secondary reinforcers gained their importance via good old classical conditioning … being predictive of UCSs that are associated with primary reinforcers (UCRs). Without secondary reinforcers we would be focused only on short-term responding, and would not learn very complex sets of behaviours … sociopaths? Chapter 5 - Learning and Behaviour

  23. Conditioning Complex Behaviours Our society contains many means to shape behaviour via aversive reinforcers (e.g., fines, jails). Punishment is an effective means of changing behaviour and it often leads to fairly immediate results … which reinforces the punisher of course. Society cannot always control the positive reinforcers present in some situation, but it can control the negative. Chapter 5 - Learning and Behaviour

  24. Current Research with Humans Rules & Reinforcers Human behaviour is often an interaction between reinforcers and rules. Rules are descriptions (often inaccurate) of behaviours that will rewarded or punished in various ways Often people will obey the rules (instructions) originally, but then modify their behaviour in accordance with the reinforcers. > text book example > rolling stop example Chapter 5 - Learning and Behaviour

  25. Current Research with Humans Drug Use and Abuse Behavioural Psychopharmocology is the study of how drugs influence behaviour. In this area, Skinner’s 3 term contingency translates into: (1) drugs, (2) their effects on behaviour, and (3) their reinforcing effects As it turns out, most psychoactive drugs act as strong reinforcers in both humans and animals Most preferred drugs correlate with those most abused by humans - Monkey coke-heads Chapter 5 - Learning and Behaviour

  26. An Few Final Thoughts Note once again the lack of attention to “thought” in all of this In response to attempts at artificial intelligence, Skinner responded, “The important question is not whether machines can be made to think, it is whether humans think” Consider this in light of the “Conditioning to Kill” situation and its possible links to post-traumatic stress disorder. Think also of the quote from “How the Mind Works” Chapter 5 - Learning and Behaviour

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