chapter 6

learning (textbook)

Learning

experience that causes a change in future behavior

conditioning

involves learning associations between events that occur in an organisms environment

classical conditioning pavolv)

a type of learning in which a stimulus acquires the capacity to evoke a response that was originally evoked by another stimulus

Pavlov’s demonstration : “psychic reflexes”

• dogs restrained

• saliva collected by presenting meat powder to dogs 

• noticed that dogs accustomed to the procedure would start salivating before meat powder was presented 

• ex: salivate in response to a clicking sound made by the device that was used to present the meat powder 

• investigated further: paired meat powder with various stimuli tone and meatpowder presented together . after several times, tone presented alone 

• dog responded by salivating to the sound of the tone alone 

• what is its significance ?: tone started out as a neural stimulus - did not produce the response of salivation, but changed the response with meat powder 

habituation 

• gradual reduction in responding 

• (baby looking at items video ex)

classical conditioning Pavlov)

• unconditioned stimulus (ucs)

• conditioned stimulus (cs)

• unconditioned response (ucr)

• conditioned response (cr)

unconditioned stimulus (ucs)

stimulus that evokes an unconditioned response without previous conditioning

unconditioned response (ucr) 

unlearned reaction to an unconditioned stimulus that occurs without previous conditioning 

conditioned stimulus (cs)

previously neural stimulus that has, through conditioning, acquired the capacity to evoke a conditioned response

conditioned response (cr)

a learned reaction to a conditioned stimulus that occurs because of previous conditioning

classically conditioned responses have traditionally been characterized as reflexes and are said to be elicited (drawn forth)

because most of them are relatively automatic or involuntary

trial

(in classical conditioning) consists of any presentation of a stimulus or pair of stimuli - pairing of unconditioned stimulus and conditioned stimulus

classical conditioning → usually related to a phobia

But everyday anxiety responses less severe than phobias → product of classical conditioning

ex: hearing a drill and cringing at the dentist

traumatic experiences associated with stimuli does not automatically lead to conditioned fears or phobias

classical conditioning procedure can lead to immune suppression - a decrease in the production of antibodies

evaluating conditioning 

(type of classic conditioning) - changes in the liking of a stimulus that results from pairing that stimulates with other pos or neg stimuli (involves the acquisition of likes and dislikes, or preferences, through classical conditioning)

ex: cartoons paired with energy drinks increased particpant’s liking of the drinks 

ex: pairing of pics of high calorie snacks with images of adverse health effects (obesity, etc) fostered neg attitudes about unhealthy snacks and led subjects to choose fruit over highly caloric snacks 

may sometimes occur without awarness 

acquisition

initial stage in learning:

refers to the initial stage of learning a new response tendency

pavolov → acquisition of a conditioned response depends on stimulus contiguity

stimuli are contiguous if they occur together in time and space

Stimulus contiguity

occurring together in time and space

extinction

gradual weakening and disappearance of a conditioned response tendency

ex: cringing at the sound of a dental drill, take job as dental assistant: start hearing drill without experiencing any pain.

Cringing response diminish and extinguish altogether

spontaneous recovery

reappearance of an extinguished response after a period of non-exposure to the conditioned stimulus (reappearing after being extinguished)

renewal effect

if a response is extinguished in a different environment than it was acquired, the extinguished response will reappear if the animal is returned to the original environment where acquisition took place. (extinction does not appear to lead to unlearning)

stimulus generalization

occurs when an organism that has learned a response to a specific stimulus responds in the same way to new stimuli that are similar to the original stimulus. (the more similar new stimuli are to the original conditioned stimulus, the greater the likelihood of generalization)

stimulus discrimination

(opposite of stimulus generalization):

• occurs when an organisim that has learned a response to a specific stimulus does not respond in the same way to new stimuli that are similar to the original stimulus

• ex: dog excited when a car pulled up in the drive way: respond the same to other cars

• but it is a stimulus discrimination if there is anything distinctive about the sound of your car (may respond with excitement only to your car and not to others)

• less similar new stimuli are to the original conditioned stimulus, greater the likelihood of discrimination

3 types of classical conditioning 

• simultaneous conditioning 

• short delayed conditioning 

• trace conditioning 

Simultaneous conditioning:

CS and UCS begin and end together

Short-delayed conditioning:

CS begins just before the UCS, end together

Trace conditioning:

CS begins and ends before UCS is presented

higher order conditioning 

a conditioned stimulus functions as if it were an unconditioned stimulus 

Processes in Classical Conditioning

• Extinction
  • Spontaneous Recovery
  • Stimulus Generalization
  • Discrimination
  • Higher-order conditioning

operant conditioning

form of learning in which voluntary responses come to be controlled by their consequences 

ex: studying because influenced by stimulus events that follow the response: consequences (grades) 

reinforcement

• organisms tend to repeat those responses that are followed by favorable consequences

• occurs when an event following a response increases an organism’s tendency to make that response. response strengthened because it leads to rewarding consequences.

skinner box :

a small enclosure which an animal can make a specific response that is systematically recorded while the consequences of the response are controlled

operant responses, such as lever pressing and disk pecking, said to be emitted rather than elicited

to emit = means to send forth

reinforcement contingencies

circumstances or rules that determine whether responses lead to the presentation of reinforcers

cumulative recorder

creates a graphic record of responding and reinforcement in a skinner box as a function of time

Edward L. Thorndike

the law of effect

B.F. Skinner (1953) – principle of
reinforcement

-Operant chamber
– Emission of response
– Reinforcement contingencies
– Cumulative recorder

operant responses are typically established through a gradual process called shaping 

• reinforcement of closer and closer approximations of a desired response 

• shaping necessary when an organisim does not on its own emit the desired response

• when rat first placed in skinner box, may not press the lever at all

• experimenter begins shaping by releasing food pellets whenever the rat moves towards the lever

• experimenters start requiring a closer approximation of desired response

resistance to extinction 

occurs when an organism continues to make a response after delivery of the reinforcer for it has been terminated (greater resistance to extinction, longer the responding will continue)

discriminative stimuli

cues that influence operant behavior by indicating the probable consequences (reinforcement or non reinforcement) of a response

ex: pigeon not getting rewarded when they peck when light is turned off, but getting rewarded when they peck when light is on

the light signals the availability of reinforcement

reactions to a discriminative stimulus are governed by the process of stimulus generalization and stimulus discrimination

primary reinforcement

events that are inherently reinforcing because they satisfy biological needs (water, food, sex)

secondary / conditioned reinforcers

events that acquire reinforcing qualities by being associated with primary reinforcers (money, good grades, attention)- most of the material things that people work hard to earn

schedule of reinforcement

specific pattern of presentations of reinforcers over time

continuous reinforcement

occurs when every instance of a designated response is reinforced. the simplest pattern is continuous reinforcement

intermittent reinforcement 

occurs when a designated response is reinforced only some of the time 

fixed-ratio (fr) schedule

reinforcer is given after a fixed number of non reinforced responses

ex: a rat reinforced for every tenth lever press

variable ratio (vr) schedule

reinforcer is given after a variable number of non reinforced responses

ex: a rat is reinforced for every 10th lever press on the average

fixed interval (FI) schedule 

reinforcer is given for the first response that occurs after a fixed time interval has elapsed 

ex: a rat is reinforced for the first lever press after a 2 min interval has elapsed and then must wait 2 min before being able to earn the next reinforcement 

variable interval (VI) schedule 

• reinforcer is given for the first response after a variable time interval has elapsed. the interval length varies around a pre determined average

ex: rat reinforced for their first lever press after 1 min interval has elapsed, but following intervals are 3 min, 2 min, 4 min, so on- with an average length of 2 min 

reinforcements can take 2 forms

• positive reinforcment

• negative reinforcement

positive reinforcement

occurs when a response is strengthened because it is followed by the presentation of a rewarding stimulus

negative reinforcement

occurs when a response is strengthened because it is followed by the removal of an aversive (unpleasant) stimulus

neg reinforcement plays a key role in both escape learning and avoidance learning (do not get confused by the word negative)

escape learning

an organism acquires a response that decreases or ends some aversive stimulation

avoidance learning

an organism acquires a response that prevents some aversive stimulation from occurring 

organisms acquire certain fears more rapidly than others because of a phenomenan called preparedness

prepardness: invovlves species- specific predispositions to be conditioned in certain ways and not others

explains why certain phobias are vastly more common than others

latent learning

learning that is not apparent from behavior when it first occurs

key processes that are crucial in observational learning

1. attention

2. retention

3. reproduction

4. motivation

matching law

Matching law:

Not only do we have one option, but we have multiple options. 

Numerical theory that allows you to calculate given the choice between the two things. 

Example: When the pigeon pecks the right button, you get 3 pellets of food 

When it pecks the left, it gets 1 pellet. 

When it’s hungry, what would it do ?

mostly it would keep pecking the key on the right- no reason to peck the key on the left

relative rate of reinforcement 

This tells you how much reinforcement (reward) each option gives relative to the total.

relative rate of behavior

This tells you how often the animal responds to each option relative to total responses.

delay discounting

Delay discounting 

• I could give you $20 right now, or tomorrow 

• If you are going to get something good, why wait for it ?

• Same thing with pigeons. Left key= 1 pellet, 2 second delay

• right key= 1 pellet,1 second delay

Relative rate of delay

It refers to how the length of delays to different rewards compare relative to each other — basically, it’s the proportion of one delay compared to the total delays of available options.

Relative rate of behavior

This measures how much an individual responds (behaves) toward one option compared to the total responding across all options

full matching law 

Human example:

-early in the day on fri, really want to study for finals 

- someone shows up and asks you to go to the movies 

-find someone else. Give them $50. If i study tn, i want 50 back. If i go to the movies, you get to keep the 50. 

-The attempt here is to describe complexity, where you have 2 choices, or 3 choices, or 17 choices . 

Left chosen 4 times more often, resulting in less
overall food.
Matching Law isn’t just about doing whatever
works best

left pellet = 0.1 sec then 1 pellet 

right pellet= 4 sec then 10 pellets 

The image demonstrates how behavior is a function of the rate and delay of reinforcement. Even though the Left key might give a very quick reward (0.1 sec), the Right key's higher overall payoff (10 pellets) and other factors (like the 6 sec delay) result in the subject heavily favoring the Right key by a 6-to-1 margin.

instinctive drift

Instinctive drift= biological constraint on conditioning. If i want to teach a pigeon to peck a key to get food, it will really learn it quickly 

If you try to get them to flap their wings for them to get a reward, it is a really hard association. 

If i want to train a pigeon to flap its wings, if the pigeon does not do anything, it gets a mild electric shock- this is easy for the pigeons to learn 

Electric shock and wing flap is easy, pecking is hard 

For food, pecking is easy but flapping is hard ??

Chat: It’s easier to train a pigeon to peck for food because pecking is part of their natural foraging behavior.
Training a pigeon to flap its wings to get food is harder because flapping is not naturally linked to getting food.
But if flapping wings helps the pigeon escape an electric shock (a negative reinforcement), it might learn that behavior more easily because flapping is part of their instinctive flight response.

Biological Constraints on Conditioning

-Instinctive Drift
– Conditioned Taste Aversion
– Preparedness and Phobias

Cognitive Influences on Conditioning

– Signal relations
– Response-outcome relations
• Evolutionary Perspectives on learning

Albert Bandura

-Observational learning
– Vicarious conditioning

vicarious conditioning

Albert Bandura’s vicarious conditioning (also called observational learning or modeling) is the process of learning behaviors by watching others and then imitating them, rather than through direct experience with rewards or punishments.

4 key processes
– attention
– retention
– reproduction
– motivation

acquisition vs. performance

Acquisition

• What it is: The process of learning or forming an association between a stimulus and a response.

• When: Happens during the initial phase of training or conditioning.

• Focus: Whether the subject is learning the behavior or association internally.

• Example: A dog gradually learning that ringing a bell means food is coming.

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Performance

• What it is: The actual demonstration or execution of the learned behavior.

• When: Happens when the subject shows the behavior in practice, which may or may not reflect what they have learned.

• Focus: What the subject does externally—the observable behavior.

• Example: The dog actually salivating or going to the food bowl when the bell rings.

observational learning

• Social learning
  • Cultural norms
  • Viewing media
  violence
  • Mirror neurons