Basic processes of learning - a summary of chapter 4 of Psychology by Gray and Bjorklund (7th edition)

Psychology
Chapter 4
Basic processes of learning

The basic processes of learning

To survive, animals must adapt to their environments.
Evolution by natural selection, is the slow long-term adaptive process that equips each species for life within a certain range of environmental conditions.
Environments changes and individuals must adapt to these changes over their lifetimes. Animals must learn.

Learning: any process through which experience at one time can alter an individual’s behavior at a future time.
Experience refers to any effects of the environment that are mediated by the individual’s sensory systems.
Behavior at a future time refers to any subsequent behavior that is not part of the individual’s immediate response to the sensory stimulation during the learning experience.

Classical conditioning

Classical conditioning is a learning processes that creates new reflexes.
A reflex is a simple, relatively automatic stimulus-response sequence mediated by the nervous system.

A stimulus results in a response.

To be considered a reflex, the response to a stimulus must be mediated by the nervous system. Because reflexes are mediated by the nervous system, they can be modified by experience.
Habituation: a decline in the magnitude of a reflexive response when the stimulus is repeated several times in succession. Not all reflexes undergo habituation.
Habituation is one of the simplest forms of learning. It does not produce a new stimulus-response sequence, but only weakens an already existing one.

Classical conditioning is a form of reflex learning that does produce a new stimulus-response sequence.
(First described by Ivan Pavlov)

Fundamentals of classical conditioning

The procedure and generality of classical conditioning

The stimulus (the bell sound by Pavlov) is a conditioned stimulus.
The response to the (condtionised stimulus, the bell) stimulus is a conditioned response.

The original stimulus (natural, before doing anything) is an unconditioned stimulus with an unconditioned response.

The procedure is called classical conditioning or Pavlovian conditioning

Pavlov concluded that, any environmental event that the animal could detect could become a conditioned stimulus of salivation. Of course classical conditioning is not limited to salivary responses.

Extinction of conditioned responses and recovery from extinction

Pavlov found that, without food, the bell elicited less and less salvation on each trial, and eventually none at all. This phenomenon is called extinction.
Extinction does not return the animal to the unconditioned state.
The mere passage of time following extinction can partially renew the conditioned response. This is called spontaneous recovery.
A single pairing of the conditioned stimulus with the unconditioned stimulus can fully renew the conditioned response (with can be extinguished with a new trial in which the conditioned stimulus is presented without the unconditioned stimulus.

The conditioned response is not lost during extinction, but is somehow inhibited.
It can be dis-inhibited by such means as the passage of time or the recurrence of the unconditioned stimulus. 

Generalization and discrimination in classical conditioning

After conditioning, animals show the conditioned response not just to the original conditioned stimulus, but also to the new stimuli that resembled that stimulus.
This phenomenon is called generalization.

The magnitude of the response to the new stimulus and the original depends on the degree of similarity between the new stimulus and the original conditioned stimulus.

Generalization between two stimuli can be abolished if the response to one is reinforced while the response to the other is extinguished.
This phenomenon is called discrimination training.

Generalization as an index of subjective similarity

(With humans)
Generalization occurs not just when two stimuli are physical similar to one another. It also occurs when they are similar in their subjective meaning of the person.

Relevance of Pavlov’s work to the emergence of behaviorism

Behaviorism:
Science should avoid terms that refer to mental entities (like thoughts). Because entities cannot be directly observed.
Psychology should focus on the relationship between observable events in the environment and observable behavior reactions to those events.

What is learned in classical conditioning?

Behaviorism → a new stimulus-response

But there is a different theory

Evidence that stimulus-stimulus associations are learned

• The animal does not learn a direct stimulus-response connection, but a connection between two stimuli (the conditioned stimulus and the unconditioned stimulus).
• If the animal has habituation with the unconditioned stimulus, it doesn't show the conditioned response to the conditioned stimulus.

Classical conditioning interpreted as learned expectancy

The stimulus-stimulus theory is more cognitive than the stimulus-response theory.
The stimulus-stimulus theory holds that the observed stimulus-response relation is mediated by an inner, mental representation of the original unconditioned stimulus.
This is expectation of the unconditioned stimulus.

Conditioned response is often different from the unconditioned response.

Conditioning depends on the predictive value of the conditioned stimulus

Conditioning occurs only when the new stimulus provides information that truly helps the animal predict the arrival of the unconditioned stimulus.
Three classes:

• The conditioned stimulus must precede the unconditioned stimulus
  This makes sense if the animal is seeking predictive information.
  Classical conditioning is most effective if the onset of the conditioned stimulus comes immediately before the unconditioned stimulus.
• The conditioned stimulus must signal heightened probability of occurrence of the unconditioned stimulus.
  The probability that the unconditioned stimulus will immediately follow must be greater than the probability that it will not follow.
  Classical conditioning occurs also on the number of times that either stimulus occurs without being paired with the other. As the number of pairings increases, conditioning is strengthened (but as the number of stimulus occurrence without pairings increases, conditioning is weakened).
• Conditioning is ineffective when the animal already has a good predictor
  Blocking does not occur if the new stimulus combined with the original stimulus is followed by and unconditioned stimulus that is larger in magnitude, or in some other way different. The new stimulus gives new information.
  If one conditioned stimulus already reliably recedes an unconditioned stimulus, a new stimulus (presented simultaneously with the original stimulus) does not become a new conditioned stimulus. This is the blocking effect. The already conditioned stimulus blocks conditioning to the new stimulus that has been paired with.

 Conditioned fear, linking, hunger and sexual arousal

Liking

Evaluative conditioning: changes in the strength of linking or disliking of a stimulus as a result of being paired with another positive or negative stimulus.

Conditioned hunger

In cases where a conditioned stimulus always precedes a specific kind of food, the conditioned hunger that occurs may be specific for that food.

Conditioned sexual arousal

Sexual arousal can be conditioned in nonhuman and human subjects.
Such conditioning is biological adaptive in the most direct sense of the term, it increases the number of offspring the animal produces.

Conditioned drug reactions

Bodily reactions associated with natural emotions and drives can be conditioned.
Bodily reactions to drugs can be conditioned.

Conditioned compensatory reaction to drugs

Many drugs have two effects:

• A direct effect
• Followed by a compensatory reaction that counteracts the direct effects and tends to restore the normal bodily state

It is often found that only the compensatory reaction becomes conditioned.
As a result a stimulus that reliably precedes delivery of the drug produces a conditioned response that is opposite of the drug’s direct effect.
Explanation: only responses that occur in a reflexive (involving the central nervous system) manner can be conditioned. The direct effects of drugs are not reflexes and therefore cannot be conditioned.

The body protects itself with counteractive reflexes to all sorts of interventions (like shoves and drugs) that disrupt its normal functioning.

Conditioned reactions as causes of drug tolerance

Drug tolerance: the decline in physiological and behavioral effects that occur with some drugs when they are taken repeatedly.
Drug tolerance depends at least partly on conditioning.
Because of conditioning, stimuli that normally precede drug intake cause the conditioned compensatory reaction to begin before the drug is actually taken. That reaction counteracts the drug.

Many cases of overdoses which in heroin are addicts who took their usual drug doses in an unusual environment.
Environments produce a conditioned compensatory reaction that allows the addict’s body to tolerate a large dose of the drug.

Conditioned reactions as causes of drug relapse after withdrawal

Another drug phenomenon that is at least partly explained by conditioned compensatory reactions is that of relapse by addicts who have undergone periods of drug withdrawal.
When drug addicts go home after a treatment center, they are once again surrounded by many cues that, for them, are associated with drug use. These clues elicit a compensatory, which feel like withdrawal symptoms.

An addict’s best hope for overcoming a long-term addiction may be to move permanently, if possible, to an entirely new environment.

Operant conditioning

Operant responses, they operate on the world to produce some effect.
Or instrumental responses, because they function like instruments to bring about some change in the environment.

The process by which people or other animals learn to make operant responses is called operant conditioning (or instrumental conditioning).
Operant conditioning: a learning process by which the effect of a response influences the future rate of production of that response.

Effects that favorable the animal; increase the rate
Effects that are unfavorable: decrease in rate

From the law of effect to operant conditioning: From Thorndike to Skinner

A trial-and-error process through which an individual gradually becomes more likely to make responses that produce beneficial effects.

Thorndike’s law of effect

Learning by altering the consequence of some aspect of the animal’s behavior.

Law of effect: responses that produce a satisfying effect in a particular situation become more likely to occur again in that situation. Responses that produce a discomforting effect become less likely to occur again in that situation.

The animals have some control over their environment.

Skinner’s method of studying and describing operant conditioning

Skinner box
A cage with a mechanism in it that the animal can operate to produce some effect.
After the response, the animal is still in the box and free to respond again.

Operant response: any behavioral act that has some effect on the environment
Operant conditioning: the process by which the effect of an operant response changes the likelihood of the response’s recurrence.

Reinforcer: a stimulus change that follows a response and increases the subsequent frequency of that response.
Conditioned reinforcers: reinforces have only value because of previous learning. (Like money)

Operant conditioning without awareness

Principles of reinforcement

Shaping of new operant responses

In operant conditioning, the reinforcer comes after the subject produces the desired response.
But, if the desired response never occurs, it can never be reinforced.
The solution for this problem is a technique called shaping.
In shaping successively closer approximations to the desired response are reinforced until the desired response finally occurs and can be reinforced.

Extinction of operantly conditioned responses

An operantly conditioned response declines in rate end eventually disappears if it no longer results in a reinforcer.
The absence of reinforcement of the response and the consequent decline in response rate are both referred to as extinction.
Extinction in operant conditioning is analogous to extinction in classical conditioning.
It is not true unlearning of the response. Passage of time following extinction can lead to spontaneous recovery of responding and a single reinforced response following extinction can lead the individual to respond again at a rapid rate. 

Schedules of partial reinforcement

Partial reinforcement
A particular response only sometimes produces a reinforcer.

Continuous reinforcement
The response is always reinforced.

In training, continuous reinforcement is most efficient, but once trained, an animal will continue to perform for partial reinforcement.

Four basic types for partial-reinforcement schedules:

• A fixed-ratio schedule
  A reinforcer occurs after nth response. N is a number greater than 1.
• A variable-ratio schedule
  Like a fixed-ratio schedule, but the number of responses required before reinforcement varies unpredictably around some average.
• Fixed-interval schedule
  A fixed period of time must elapse between one reinforced response and the next. Any response occurring before that time elapses is not reinforced.
• Variable-interval schedule
  The period that must elapse before a response will be reinforced varies unpredictably around some average.

Different schedules produce different response rates in ways that make sense if we assume that the individual is striving to maximize the number of reinforces and minimize that number of unreinforced responses.
Ratio schedules typically induce rapid responding.
Interval schedules result in low response rates that depend on the length of the fixed average interval.

Behavior that has been reinforced on a variable- schedule is often very difficult to extinguish. They have learned to be persistent.

Distinction between positive and negative reinforcement

Two types of reinforcement and punishment:
Positive: when the arrival of some stimulus follows the response
Negative: when the removal of some stimulus follows the response

(Positive and negative not in the moral way)

The same stimulus can serve positive and negative. It can be added and removed.
Desired stimuli and undesired stimuli.

Discrimination training in operant conditioning

Discrimination training in operant conditioning is analogous to discrimination conditioning training in classical conditioning.
The essence is to reinforce the animal’s response when a specific stimulus is present and to extinguish the response when the stimulus is absent.

Discriminative stimulus
Operant discrimination training can be used to study animal’s understanding of concepts.

Discrimination and generalization as indices of concept of concept understanding

Generalization occurs in operant conditioning.
After operant discrimination training, animals will respond to new stimuli that they perceive as similar to the discriminative stimulus.

Concept: a rule for categorizing stimuli into groups.

Sophisticated analysis of the stimulus information occurs before the stimulus is used to guide behavior.

When rewards backfire: the over-justification effect in humans

Rewards tied to specific performance or completion of a task are negatively associated with creativity.
The drop of performance or following a period of reward is particularly likely to occur when the task is something that is initially enjoyed for its own sake and the reward is given in such a manner that it seems
to be designed deliberately to motivate the participants to engage in the task.
This is the over justification effect.
The reward provides an unneeded extra justification for engaging in the behavior.

Beyond classical and operant theories of learning: play, exploration and observation

• Play
  Young animals learn to control their own behavior in effective ways
• Exploration
  Animals keep track of significant changes in the environment
• Observing
  Acquire information by looking at the behavior of others of their kind.

Play, how the young learn how

Play is behavior that serves no obvious immediately useful purpose.
Play is species-typical.

Groos’s theory; play is practice of species-typical skills

The primamy purpose of play is to provide a means for young animals to practice their instincts.

Evidence for Groos’s theory

Five categories of evidence:

• Young animals play more than do adults of their species
  Young animals have more to learn.
• Species of animals that have the most to learn play the most
• Young animals play most at those skills that they most need to learn
• Play involves much repetition
• Play is challenging

Applying the theory to humans

We humans have at least as many species-typical behaviors as other mammals have, but ours are less rigid, more modifiable by experience, enabling us to adapt to a wider range of environmental niches than is true for other mammals.
We are the only truly cultural species.
To do well as human, we must learn not just the skills that are common to the whole species, but also those that are unique to the specific culture in which we are developing.

Play has been seen as a preparation for adulthood. But play also provides some immediate benefits for the players.
Like physical exercise that is important for skeletal and muscle development.
Children develop a sense of mastery during play when experimenting with new activities
Learning of social signaling
Establish leadership

Exploration: how animals learn what and where

Exploration is information learning
Learning about the environment.

The nature of mammalian exploration

Exploration is often mixed with a degree of fear. This is in balance with curiosity.
Patrolling.

Evidence that animals acquire useful information through exploration

Rewards affect what animals do more than what they learn.
Latent learning: learning is not immediately demonstrated in the animal’s behavior.

Animals that explore the most are the same animals that learn the most in a wide variety of test of learning.

Social learning: learning by watching and interacting with others

Social learning: a situation in which one individual comes to behave similarly to others
Observational learning: watching others

Vicarious reinforcement: the ability to learn from the consequences of others’ actions.

Learning how by watching skilled performers

Animals can learn or partially learn how to perform a new task by watching others do it.
Imitation is cognitively complex.
To imitate an animal must observe, remember, and reproduce the specific pattern of movements that were produced by the model. To reproduce the movements, the learner must map the observed actions onto its own movement control system.

Stimulus enhancement: an increase in the salience or attractiveness of the object that the observed individual is acting upon.
Goal enhancement: an increased drive to obtain rewards similar to what the observed individual is receiving.

Emulation: observing another individual achieve some goal, then reaching that same goal by their own means. It is more focused on the goal, and less on the means used to achieve it.

Mirror neurons: organized systems of neurons that seem to be well designed to make imitation easy and natural.
Within this system, the same neurons that become active when the individual makes a particular motion also become active when the individual sees another individual make that motion.
In terms of this neurons, observing is like doing.

Cultural transmission in chimpanzees

Culture: the beliefs and traditions that are passed along from generation to generation.
Most social learning in our close genetic relatives is not achieved by teaching, but by other less complex forms observational learning, such as emulation.

Gaze following as an aid in learning from others

When we are attending to another person our eyes move automatically in the same direction that his or her eyes move, so we look at the same object.
This reflexive action is called gaze following.
It helps us understand what the other person is thinking about.

No other animal follows the gaze of another to the extent humans do.

Specialized learning abilities: filling the blanks in species-typical behavior patterns

Each species-typical learning ability helps to mesh some aspects of the animal’s species-typical behavior with particular variable characteristics of the animal’s environment.

Special abilities for learning what to eat

Omnivorous creatures must learn what is safe to eat.
Such animals have evolved special mechanisms for learning to identify healthful foods and avoid potential poisons.

Food-aversion learning: how it differs from typical classical conditioning

 Learning of food-aversion is different from classical conditioning.

• One special characteristic of food-aversion learning as to do with the optimal delay between the conditioned and unconditioned stimuli.
  Food-aversion learning fails to occur if the gap between tasting the food and the induction of illness is less than a few minutes.
• One characteristic has to do with the sorts of stimuli that can serve as conditioned stimuli for such learning
  The stimuli must be a distinctive taste or smell

There is a continuum of preparedness, such that animals are prepared by natural selection to make some associations and unprepared, or even contra-prepared of others.

Prepared behaviors: learned behaviors that are vital to an organisms survival
Unprepared behaviors: those acquired through the normal processes of operant conditioning and usually take repeated trials to learn
Contra-prepared behaviors: those that are difficult or impossible to learn despite the training.

Food-preference learning

Animals learn to prefer food that is high in calories.
Some delayed satisfying effect of the calories causes the students to develop a preference for the high-calorie food.

Learning from others what to eat.

Rats learn what to eat from another.

Humans are influenced by our observations of what those around us eat.
Food preferences can even begin while still in the womb.

Summary of rules for learning what to eat

• When possible, eat what your elders eat.
• When you eat new food, remember its taste and smell

Other examples of special learning abilities

Prepared fear-related learning

Humans are biological predisposed to acquire fears of situations and objects that posed thread to our evolutionary ancestors, and are less disposed to acquire fears of other situations and objects.

Imprinting in precocial birds: learning to identify one’s mother

Precocial birds: species in which the young can walk almost as soon as they hatch.
Because they can walk, they can get separated of their mother. To avoid that, they have an efficient mean to determine who their mother is and a drive near her.
This is imprinting.
Imprinting can occur in a restricted critical period.

Natural selection has worked out that the brain, sensory organs, and experience are coordinated to produce a valuable adaptive behavior.

Specialized place-learning abilities

Many animals have specialized abilities for learning and remembering specific locations that have biological significance to them.