Unit 4: Learning
Applications of classical conditoning
Drug cravings: Former drug users often feel a craving when they are again in the drug-using context Food cravings: classical conditioning maes dieting difficult because we readily associate sugary substances with an enjoyable sweet sensation.
Neutral Stimuli (NS)
in classical conditioning, a stimulus that elicits no response before conditioning
Operant conditioning
- A type of learning in which behavior is more likely to recur if followed by a reinforcer or less likely to recur if followed by a punisher - Behavior that operates on the environment to produce rewarding or punishing stimuli is operant behavior.
Ivan Pavlov (1849-1936)
- Classic experiments exploring classical condition Laid foundation for many of psychologist John B. Watson's ideas: - Watson believed psychology should be an objective science based on observable behavior (Behaviorism: The view that psychology 1. should be an objective science that 2. studies behavior without reference to mental processes. Most research psychologists today agree with 1. but not with 2.) - Behaviorism influenced North American psychology in the 1st half of the 20th century. Pavlov & Watson shared a disdain for "mentalistic" concepts (like consciousness) and a belief that the basic laws of learning were the same for all animals. Classical conditioning is a basic form of learning by which all organisms adapt to their environment.
Comparing classical and operant conditioning
- Forms of associative learning - Include acquisition, extinction, spontaneous recovery, generalization, discrimination
Acquisition
- In classical conditioning, the initial stage, when one links a neutral stimulus and an unconditioned stimulus so that the neutral stimulus begins triggering the conditioned response. In operant conditioning, the strengthening of a reinforced response. - Conditioning usually won't occur when the NS follows the US. Remember, classical conditioning is biologically adaptive because it helps humans and other animals prepare for good or bad events. - Higher-order conditioning: a procedure in which the CS in one conditioning experience is paired with a new NS, creating a second (often weaker) CS. For example, an animal that learned that a tone predicts food might then learn that a light predicts tone and begin responding to the light alone (Also called second-order conditioning).
1. Association
- Our minds naturally connect events that occur in sequence Ex: associating a sound with a frightening consequence, hearing the sound alone may trigger your fear. Learned associations feed our habitual behaviors - Habits form when we repeat behaviors in a given context. As behavior becomes linked with the context, our next experience of that context will evoke our habitual response. - Behaviors become habitual after 66 days. Habituation: decreasing responsiveness with repeated exposure to a stimulus
Pavlov's Experiment
- Pavlov observed putting food in a dogs mouth caused salivation. Moreover, the dog began salivating not only to the taste of food, but to the mere sight of the food or food dish, or the person delivering the food & the sound of their footsteps. - Pavlov realized these psychic secretions pointed to a simple but fundamental form of learning. - He experimented by pairing various neutral stimuli (ns) (in classical conditioning, a stimulus that elicits no response before conditioning) -events the dog could see/hear but didn't associate with food - with food in dogs mouth. - Just before placing food in the dog's mouth to produce salivation, Pavlov sounded a tone. The dog began associating the pairing of tone and food and began salivating to the tone alone. - Pavlov called drooling an unconditioned response (UR) because a dog does not learn to salivate in response to food in its mouth. Rather, food in the mouth automatically, unconditionally, triggers a dog's salivary relief. He called the food an unconditioned stimulus (US). - Salivation in response to a tone is learned. It is conditioned upon the dog's associating the tone with the food. This response is the conditioned response (CR) - The stimulus that used to be neutral (ex. previously meaningless tone that now triggers salivation) is the conditioned stimulus (CS) Conditioned = learned; unconditioned = unlearned
How Pavlov influenced Watson
- Pavlov's work provided a basis for Watson's (1913) idea that human emotions and behaviors, though biologically influenced, are mainly a bundle of conditioned responses - Watson worked with "Little Albert" to show how specific fears might be conditioned - Presented Albert with a white rat, then made a frightening noise. After 7 repeats of seeing the rat and hearing the frightening noise, Albert cried at the mere sight of the rat. Five days later, he had generalized this startled fear reaction to the sight of a rabbit, a dog, a sealskin coat, but not to dissimilar objects like toys.
Types of Reinforcers
1. Positive reinforcement: Increasing behaviors by presenting positive reinforcers. A positive reinforcer is any stimulus that, when presented after a response, strengthens the response. Add a desirable stimulus 2. Negative reinforcement: Increasing behaviors by stopping or reducing aversive stimuli. A negative reinforcer is any stimulus that, when removed after a response, strengthens the response (Negative doesn't mean punishment). Remove an aversive stimulus. Reinforcement is any consequence that strengthens behavior. Primary and Conditioned Reinforcers 3. Primary reinforcers: An innately reinforcing stimulus, such as one that satisfies a biological need. Unlearned 4. Conditioned reinforcers: A stimulus that gains its reinforcing power through its association with a primary reinforcer (secondary reinforcer) - Money is a conditioned reinforcer derived from people's desire for food - Money, good grades, a pleasant tone of voice Immediate and Delayed Reinforcers - Some response, if not rewarded in a specific frame of time, will not get reinforced - Delayed reinforcers examples: The paycheck at the end of the week, the good grade at the end of the term, the trophy at the end of the season - To our detriment, small but immediate pleasures (staying up watching Naruto) are more alluring than big but delayed rewards (rested for a big test the next day)
4 major drawbacks of physical punishment
1. Punished behavior is suppressed, not forgotten. This temporary state may negatively reinforce parents' punishing behavior. 2. Punishment teaches discrimination among situations. Discrimination occurs when an organism learns that certain responses, but not others, will be reinforced. 3. Punishment can teach fear. In operant conditioning, generalization occurs when an organisms response to similar stimuli is also reinforced. Causes fear of parents. 4. Physical punishment may increase aggression by modeling aggression as a way to cope with problems
Classical Conditioning
A type of learning in which we link two or more stimuli; as a result, to illustrate with Pavlov's experiment, the first stimulus (a tone) comes to elicit behavior (drooling) in anticipation of the second stimulus (food)
Biopsychosocial influences on learning
Biological influences - Genetic predispositions - Unconditioned responses - Adaptive responses - Neural mirroring
Biological limits on classical conditioning
An animal's capacity for conditioning is limited by biological constraints - Each species' predispositions prepare it to learn the associations that enhance its survival (preparedness) - Preparedness: a biological predisposition to learn associations such as between taste + nausea, that have survival value John Garcia - Challenged the prevailing idea that all associations can be learned equally well. Taste aversion: Becoming ill after eating food causes you to have a hard time eating that food again. its taste and smell become a CS for nausea. This learning occurs rapidly because our biology prepares us to learn taste aversions to toxic foods - Contradicted behaviorists' idea that any perceivable stimulus could serve as a CS, but makes adaptive sense - Our preparedness to associate a CS with a US that follows predictably and immediately is adaptive.
Punishment
An event that tends to decrease the behavior that it follows Positive punishment: administer an aversive stimulus Negative punishment: withdraw a rewarding stimulus Punishment tells you what not to do; reinforcement tells you what to do
Contrasting Classical and Operant Conditioning
Classical conditioning Basic idea: learning associations between events we don't control Response: Involuntary, automatic Acquisition: Associating events; NS is paired with US and becomes CS Extinction: CR decreases when CS is repeatedly presented alone Spontaneous recovery: The reappearance after a rest period, of an extinguished CR. Generalization: The tendency to respond to stimuli similar to the CS Discrimination: Learning to distinguish between a CS and other stimuli Operant Conditioning Basic idea: Learning associations between our behavior and its consequences Response: Voluntary, operates on environment Acquisition: Associating a response with a consequence (reinforcer or punisher) Extinction: Responding decreased when reinforcement stops Spontaneous recovery: The reappearance after a rest period, of an extinguished response. Generalization: Responses learned in one situation occurring in other, similar situations Discrimination: Learning that some responses, but not others will be reinforced
Pavlov's Legacy
Importance #1: The finding that many other responses to many other stimuli can be classically conditioned in many other organisms - Classical conditioning is one way that virtually all organisms learn to adapt to their environment Importance #2: Showed us how a process such as learning can be studied objectively
Unconditioned stimulus (US)
In classical conditioning, a stimulus that unconditionally -naturally and automatically- triggers an unconditioned response (UR)
Conditioned stimulus (CS)
In classical conditioning, an originally neutral stimulus that, after association with an unconditioned stimulus (US), comes to trigger a conditioned response (CR).
Unconditioned response (UR)
In classical conditioning, an unlearned, naturally occurring response to an unconditioned stimulus (US)
Discrimination
In classical conditioning, the learned ability to distinguish between a conditioned stimulus and similar stimuli that do not signal an unconditioned stimulus. In operant conditioning, the ability to distinguish responses that are reinforced from similar responses that are not reinforced - Pavlov's dogs learned to respond to the sound of a particular tone and not to other tones.
Conditioned response (CR)
In classical conditioning, the learned response to a previously neutral (but now conditioned) stimulus (CS)
Associative learning
Learning that certain events occur together. The events may be two stimulus (as in classical conditioning) or a response and its consequence (operant conditioning). - Used for learning something important to its survival: anticipating the immediate future The process of learning associations is conditioning. It takes two main forms: 1. In classical conditioning, we learn to associate two stimuli and thus to anticipate events - Respondent behavior: behavior that occurs as an automatic response to some stimulus. We associate stimuli that we do not control, and we respond automatically. 2. In operant conditioning, we learn to associate a response (our behavior) and its consequence. - Repeat acts followed by good results, avoid acts followed by bad results - Produce operant behavior: behavior that operates on the environment, producing consequences.
Reinforcement Schedules
Reinforcement schedule: A pattern that defines how often a desired response will be reinforced 1. Continuous reinforcement: reinforcing the desired response every time it occurs. - Learning occurs rapidly, so it's the best choice for mastering a behavior, but extinction also occurs rapidly. Spontaneous recovery may occur after extinction 2. Partial (intermittent) reinforcement schedule: Reinforcing a response only part of the time; results in slower acquisition of a response but much greater resistance to extinction than does continuous reinforcement - Fixed-ratio schedule: A reinforcement schedule that reinforces a response only after a specified number of responses - Variable-ratio schedule: A reinforcement schedule that reinforces a response after an unpredictable number of responses. Produce high rates of responding since reinforcers increase as # of responses increases - Fixed-interval schedule: A reinforcement schedule that reinforces a response only after a specified time has elapsed. Produces a choppy stop-start pattern rather than a steady rate of response - Variable-interval schedule: A reinforcement schedule that reinforces a response at unpredictable time intervals. Variable-interval schedules tend to produce slow, steady responding. - Responding is more consistent when reinforcement is unpredictable (a variable schedule) than when it is predictable (a fixed schedule)
Shaping Behavior
Shaping: an operant conditioning procedure in which reinforcers guide behavior toward closer and closer approximations of the desired behavior. Ex: giving food closer and closer to the bar till the animal has to touch the bar to get food. - Rewarding successive approximation to reinforce responses that are ever closer to the final desired behavior & ignore all other responses. Rewards are contingent on desired behaviors, can gradually shape complex behaviors - Shaping can help us understand what nonverbal organisms can perceive. If we can shape them to one stimulus and not to another, then we know they can perceive the difference. - Discriminative stimulus: In operant conditioning, a stimulus that elicits a response after association with reinforcement (in contrast to related stimuli not associated with reinforcement)
Skinner's legacy
Skinner argued that behaviors were shaped by external influences instead of inner thoughts and feelings. Critics argued that Skinner dehumanized people by neglecting their free will. Urged people to use operant conditioning principles to influence others' behavior. Rewards to evoke more desirable behavior.
Skinner's Experiments
Skinner's work elaborated on Thorndike's law of effect: Rewarded behavior tends to recur, and punished behavior is less likely to recur. Skinner developed a behavioral technology that revealed principles of behavior control with pigeons Operant chamber (a skinner box): In operant conditioning research, a chamber containing a bar or key that an animal can manipulate to obtain a food or water reinforcer; attached devices record the animal's rate of bar pressing or key pecking. - Animals act out Skinner's concept of reinforcement: In operant conditioning, any event that strengthens the behavior it follows
2. Cognitive learning
The acquisition of mental information, whether by observing events, by watching others, or through language. - Observational learning: One form of cognitive learning that lets us learn from others experiences.
Biological constraints on conditioning
The basic laws of learning were essentially similar in all animals Any natural response could be conditioned to any neutral stimulus
Extinction
The diminishing of a CR; occurs in classical conditioning when an unconditioned stimulus (US) does not follow a conditioned stimulus (CS); occurs in operant conditioning then a response is no longer reinforced
Learning
The process of acquiring through experience new and relatively enduring information or behaviors. We learn to adapt to our environments - Classical conditioning: We learn to expect and prepare for significant events - Operant conditioning: We learn to repeat acts that bring rewards and avoid acts that bring unwanted results - Cognitive learning: We learn new behaviors by observing events & people How we learn: Association and Cognitive Learning
Spontaneous recovery
The reappearance, after a pause, of an extinguished conditioned response. Suggested to Pavlov that extinction was suppressing the CR rather than eliminating it.
Generalization
The tendency, once a response has been conditioned, for stimuli similar to the conditioned stimulus to elicit similar responses. In operant conditioning, generalization occurs when responses learned in one situation occur in the other, similar situations. - Generalization can be adaptive, like toddlers learning to fear moving cars will fear moving trucks and motorcycles. - Generalized fears can linger. (from abuse/torture) - Stimuli similar to naturally disgusting objects will, by association, also evoke some disgust - People's emotional reactions to one stimulus can be generalized to other stimuli
biofeedback
a system for electronically recording, amplifying, and feeding back information regarding a subtle physiological state, such as blood pressure or muscle tension to manage stress
Pavlov explored 5 major conditioning processes:
acquisition, extinction, spontaneous recovery, generalization, and discrimination
Applications of operant conditioning
school, sports, work, home