Learning Flashcards

Learning

Definition of Learning

• Learning is defined as a long-lasting change in behavior resulting from experience.
• Brief changes in behavior are not considered learning.

Neuroplasticity

• Neuroplasticity is the brain's ability to change throughout an individual’s life.
• Brain activity associated with a given function can be transferred to a different location.
• The proportion of neurons can change.
• Synapses may strengthen or weaken over time.

Long-Term Potentiation (LTP)

• LTP is a persistent strengthening of synapses based on recent patterns of activity.
• These patterns of synaptic activity produce a long-lasting increase in signal transmission between two neurons.

Classical Conditioning

• Classical conditioning involves forming an association with some sort of already naturally occurring event.
• Described by Ivan Pavlov.
• Involves placing a neutral signal before a reflex or involuntary behavior (e.g., blinking, salivating, muscle tension).

Pavlov's Experiment

• Pavlov made observations about learning and coined classical conditioning.
• The experiment involved a dog, food, a bell (or tuning fork), and measurements of salivation.
• Before conditioning:
  • Food (Unconditioned Stimulus) leads to salivation (Unconditioned Response).
  • Tuning fork (Neutral Stimulus) leads to no salivation.
• During conditioning:
  • Tuning fork is presented with food, leading to salivation (Unconditioned Response).
• After conditioning:
  • Tuning fork (Conditioned Stimulus) leads to salivation (Conditioned Response).

Classical Conditioning Terminology

• Unconditioned stimulus: The original stimulus – the food.
• Unconditioned response: The response towards that unconditioned stimulus – the salivating.
• Neutral stimulus: A stimulus that has no conditioned response – a bell.
• Conditioned stimulus: What the organism has learned to pair – the bell.
• Conditioned response: The response from the conditioned stimulus.

Types of Conditioning

• Delayed conditioning: Acquisition occurs fastest if the bell is rung, and while it is still ringing, the dogs are presented with food.

• Trace conditioning: The CS begins and ends before the US is presented. The stimulus-free period is called the trace interval or the conditioning interval.
  *Auditory CS
  Footshock US
  Delay Conditioning
  Auditory CS
  Footshock US

• Simultaneous conditioning: the CS and US are presented and terminated at the same time.

• Backward conditioning: US is presented first and is followed by the CS. This is very ineffective.

Acquisition and Extinction

• Acquisition: Learning has taken place once the animal responds to the CS without a presentation of the unconditioned stimulus.
• Extinction: The process of unlearning behavior. Extinction has taken place when the CS no longer exhibits a CR (bell no longer causes salivation).

Spontaneous Recovery

• Sometimes, after a conditioned response has been extinguished and no further training has taken place, CR will appear in the presence of the CS.

Generalization and Discrimination

• Generalization: Animals may come to generalize the sound of the bell with other stimuli, like a tuning fork or a whistle.
• Discrimination: Animals can be trained to discriminate between stimuli, responding to a bell and not a whistle.

Little Albert Experiment

• John B. Watson: Little Albert and Aversive conditioning

• Before conditioning:

  • Neutral stimulus (white rat) and no fear.
  • Steel bar hit with a hammer (UCS) leads to UCR (fear).

• During conditioning:

  • Neutral stimulus (white rat) + UCS (steel bar hit with hammer) leads to UCR (fear).

• After conditioning:

  • CS (white rat) leads to CR (fear).

Aversive Conditioning

• Aversive conditioning is commonly used.
• Example: people who paint their nails with a terrible tasting material to stop themselves from biting their nails.

Higher Order Conditioning

• First order conditioning is the regular process of pairing a neutral stimulus with an unconditioned response (bell with salivating).
• Second order conditioning is pairing another neutral stimulus (a light) with the previously conditioned stimulus (the bell) in order to eventually make the light a conditioned stimulus.

Learned Taste Aversions

• If you ingest an unusual food or drink, and then you become nauseous, you’ll most likely develop an aversion to that particular food.
• In some therapeutic settings, therapists give alcoholics a drinking containing a nausea-producing drug.

Garcia & Koelling Experiment

• Garcia & Koelling illustrate how rats more readily learned to make certain associations than others.
• They made rats learn that a noise would be paired with a shock and an unusual-tasting water with nausea.
• However, the rats were unable to make the connection between unusual tasting water and the shock.

Instrumental Learning

• Edward Thorndike
• The law of effect states that if the consequences of a behavior are pleasant, the stimulus-response (S-R) connection will be strengthened and the likelihood of the behavior will increase. If the S-R connection is unpleasant, the likelihood of the behavior will decrease.

Thorndike's Experiment

• Experiment involved a cat in a puzzle box.
• The time required to escape decreased over trials.

Operant Conditioning

• First described by B. F. Skinner, an American psychologist.
• Involves applying reinforcement or punishment after a behavior.
• Behavior is either strengthened or weakened by reinforcement or punishment.
• Operant conditioning is a learning process through which the strength of a behavior is modified by reinforcement or punishment.

Reinforcement

• Reinforcer/reinforcement: Anything that makes a behavior more likely to occur is a reinforcer.
• Positive reinforcement: Adding something pleasant. For example, food, shelter, water.
• Negative reinforcement: removing something unpleasant. For example, a loud noise, darkness, pain.

Punishment

• Punishment is anything that makes a behavior less likely to reoccur.
• Positive punishment: Adding an aversive stimulus to decrease behavior. For example, a shock.
• Negative punishment (omission training): Removing a pleasant stimulus to decrease behavior. For example, taking away a child’s toy.

Escape & Avoidance

• Escape conditioning (or escape learning) occurs when an aversive stimulus is presented and an animal responds by leaving the stimulus situation.
• Avoidance conditioning (learning) enables one to avoid the unpleasant stimulus altogether.
• Both escape and avoidance conditioning are types of negative reinforcement, both result in an increase of the behavior that terminated or avoided the aversive stimulus.

Reinforcement vs. Punishment

• Reinforcement: Increases/Maintains Behavior
• Punishment: Decreases Behavior
• Positive (add stimulus)
  • Add a pleasant stimulus to increase/maintain behavior
  • Add an aversive stimulus to decrease behavior
• Negative (remove stimulus)
  • Remove aversive stimulus to increase/maintain behavior
  • Remove pleasant stimulus to decrease behavior

Shaping

• Shaping reinforces the steps used to reach a single desired behavior.

Chaining

• Chaining: Involves reinforcing individual responses occurring in a sequence to form a complex behavior.
• For example, rewarding an animal after completing an obstacle course.
• The goal of shaping is to mold a single behavior (e.g., a bar press by a rat), the goal of chaining is to link together a number of separate behaviors into a more complex activity.

Types of Reinforcers

• Primary reinforcers: things like food, water, rest, sex. They are rewarding generally because they help the organism survive.
• Secondary reinforcers: are things that the organism has learned to have value. For example, saying thank you, getting good grades, showing up on time, etc.
• Money is called a generalized reinforcer because it can be traded for virtually anything.

Premack Principle

• Reinforcement differs between individuals.
• Premack Principle: Whichever of two activities is preferred can be used to reinforce the activity that is not preferred.
• Apple and piano example

Continuous & Partial Reinforcement

• Continuous reinforcement: Continuously rewarding a particular behavior.
• Partial-reinforcement: Rewarding a particular behavior on some trials.
• Partial-reinforcement effect: Behaviours will be more resistant to extinction if the animal has not be reinforced continually.

Schedules of Reinforcement

• Schedules of reinforcement are the rules that determine how often an organism is reinforced for a particular behavior.
• Fixed Ratio: Reinforcement is delivered after a fixed number of responses (press this lever 40 times and you get…).
• Fixed Interval: Reinforcement is delivered after a behavior is performed following the passage of a fixed amount of time.

Variable Schedules of Reinforcement

• Variable ratio: Reinforcement is delivered after a variable number of responses (this is how slot machines work – sometimes they pay out on the first pull, sometimes after hundreds).
• Variable interval: Reinforcement is delivered after a behavior is performed following the passage of a variable amount of time.

Schedules of Reinforcement Comparison

• Fixed Interval
  • Reward on fixed time basis
  • Leads to average and irregular performance
  • Fast extinction of behavior
• Fixed Ratio
  • Reward tied to specific number of responses
  • Quick and stable performance
  • Moderately fast extinction of behavior
• Variable Interval
  • Reward given after varying periods of time
  • Leads to moderately high and stable performance
  • Slow extinction of behavior
• Variable Ratio
  • Reward given for some behaviors
  • Quick and stable performance
  • Very slow extinction of behavior

Observational Learning

• Albert Bandura
• Observational Learning: People and animals learn through observing others.
• Modeling has two components: observation and imitation.

Contingency Model

• Rescorla’s Contingency model of classical conditioning reflects a cognitive spin on classical conditioning, positing that it is necessary for one event to reliably predict another for a strong association between the two to result – while Pavlov’s model holds that the strength of an association between two evens is closely linked to the number of times they have been paired in time.

Abstract Learning

• Abstract learning involves understanding concepts such as a tree or different rather than just learning to peck at a disk in order to secure a reward.
• Pigeons have been shown a particular shape (square or triangle) and rewarded in one series of trails when they picked the same shape out of two choices.
• Suggests that pigeons can understand concepts rather than just S-R connections.

Latent Learning

• Edward Tolman
• Tolman conducted an experiment with three sets of rats.
• The first set was rewarded for completing a maze.
• The second set never received any rewards.
• Third set was not rewarded during the first half of the trials. The third group’s performance was very similar to the second group – slow.

Latent Learning Results

• However, the third group’s performance improved dramatically and suddenly once it began to be rewarded for finishing the maze.

Latent Learning Implications

• The third group of rats learned their way around in the first trials, but their performance did not improve because they was no incentive to run the maze quickly.
• Tolman suggested that the dramatic increase in performance was due to the rats making a mental map of the maze during the first trial and then used this knowledge once they were aware that they’d be rewarded.

Insightful Learning

• Wolfgang Kohler and Insightful learning
• Insight learning occurs when one suddenly realizes how to solve a problem.
• Kohler argued that learning often happened in this sudden way due to insight rather than because of the gradual strengthening of the SR (stimulus-response) connection.