11 Flashcards
Reflex
a behaviour that is automatically elicited by an environmental stimulus
E.g., blink when something rapidly approaches your eye
Habituation
the reduction in response strength of a reflex over repeated presentations of the stimulus
Imagine you’re a circus performer => things being thrown at you everyday lowers and stops your reflex to duck and dodge
Classical conditioning (Pavlovian conditioning)
The learning of a new association between two previously unrelated stimuli
• We learn that a stimulus predicts a certain event and we respond accordingly.
• In classical conditioning, all responses are reflexes or autonomic responses that are elicited by environmental stimuli.
Unconditioned stimulus
A stimulus that elicits an unconditioned response without previous conditioning.
(meat in pavlov’s experiment)
Unconditioned response
An unlearned reaction to an unconditional stimulus (UCS) that occurs without previous conditioning
(drooling in pavlov’s experiment)
Conditioned stimulus
A previously neutral stimulus that has acquired the capacity to elicit a conditioned response (CR)
(bell in pavlov’s experiment)
Conditioned response
A learned reaction to an conditioned stimulus (CS) that occurs because of previous conditioning
(response to the bell Pavlov’s experiment)
Acquisition in classical conditioning
The process of acquiring a new association between stimuli (e.g., food + bell)
It takes a certain number of pairings for association to become clear
▫ The process of pairing a conditioned stimulus with an unconditioned stimulus.
▫ The conditioned stimulus will acquire the ability to elicit a conditioned response
How does conditioning effect us ?
Advertising
▫ Associations between products and other stimuli
can be formed through advertising
▫ The main aim is that these associations will lead to a change in behaviour (e.g. purchase the product)
What gets conditioned ?
• Classical conditioning can change behaviour, physiology, emotions, and/or cognition
Learning
Any enduring change in the way an organism responds, based on its experiences.
▫ Implies change/adaptation
▫ Necessary for survival
• Key issue: Learning cannot be observed
directly. It is inferred from behaviour that is observed.
Changes in behaviour
▫ Changes in behaviour
- e.g Salivation
- For humans can be the establishment of avoidance or
preferences
Changes in physiology
Increased heart rate, skin conductance responses and muscle tension during a conditioned stimulus paired with an aversive stimulus
Changes in emotion
Conditioned stimuli paired with an aversive event are rated as less pleasant and more arousing than they were before conditioning
Neutral stimuli paired with a “liked” stimulus becomes more liked after conditioning
Changes in cognition
- Increased expectancy of the unconditional stimulus when the conditional stimulus is presented (law of prediction)
- Formulation of plans or reactions to conditional stimulus (e.g. how to avoid impact of unconditional stimulus)
Conditioned taste aversion
• A learned aversion to a taste associated with an unpleasant feeling, usually nausea.
• Takes just one trial to develop
• Evolutionary adaptation
UCS (Toxic Event) => UCR (Nausea)
NS (Taste of Prawns) + UCS (Toxic Event) => UCR (Nausea)
CS (Taste of Prawns) => CR (Nausea)
Pavlov and his dogs
Used a bell to indicate the times of the day the dogs would be fed
- when they were shown the food and fed the dogs would drool
- eventually upon hearing the bell the dogs would drool, even without the presence of food
3 temporal relations
- Simultaneous conditioning
- forward conditioning
- backward conditioning
Simultaneous conditioning
UCS & CS begin end end together
Bell begins to ring at the same time the food is presented. Both begin, continue, and end at the same time.
Forward conditioning
CS begins just before UCS
Bell begins to ring and continues to ring as until food has been presented.
- Most effective temporal relation
Backward conditioning
UCS begins before CS begin
The food is presented, and then the bell rings
- Least effective temporal relation
Extinction in classical conditioning
- The weakening of the conditioned response when the conditioned stimulus is presented without the unconditioned stimulus.
- Bell, but no food
- Time taken to extinguish CR depends on the strength of the conditioned bond when extinction begins
- Extinction is not an unlearning of the conditioned response. It is a learned inhibition of responding.
- Important implications for treatment of phobias.
Phobias
• Behavioural treatment for phobia is based on extinction
▫ The fear is so strong this is usually done in steps through systematic desensitisation
step 1 photograph of a spider in a book
step 2 spider in a jar
step 3 holding spider in jar
step 4 spider on table
step 5 holding spider
Spontaneous recovery
▫ If there is a break after extinction, a conditional response will be shown upon another presentation of the conditioned stimulus
▫ This “spontaneous recovery” response will typically be smaller than before extinction
▫ The longer the delay, the larger the spontaneous recovery
Renewal effect
- If a CR is extinguished in an environment different to the real environment, then the extinguished response will re-appear when the animal (or person!) is returned to the real environment
- Spontaneous recovery and renewal effect suggest that extinction suppresses a CR but CR is not unlearned
Stimulus generalisation
- Organism that has learned a response to the specific stimulus responds in the same way to new stimuli that are similar
- A conditioned response will be elicited by other stimuli that are similar to the original conditional stimulus
- The conditional response is not usually as large as it is to the original conditional stimulus
- Generalisation gradient – the more similar the stimulus to the conditional stimulus, the larger the conditioned response
- Little Albert’s conditioned fear of rats generalised to other furry white objects.
Stimulus discrimination
- If a response is conditioned to one stimulus, the organism may also respond to a similar stimulus (generalisation) but not to a dissimilar stimulus (discrimination).
- Pavlov’s dogs were able to discriminate between different tones/bells: learned which bells meant food and which didn’t
3 factors affecting conditioning
- Stimulus contingency/Inter-stimulus interval
- Individual learning history
- Biological preparedness
Stimulus contingency / inter-stimulus interval
▫ Time between presentations
▫ Order of presentation
- forward, backward and simultaneous conditioning
Individual learning history
▫ Prior history with stimuli
- Previously learned but extinguished associations are
easier to learn than “new” associations
▫ Blocking
- Failure of a stimulus to elicit a conditioned response
when it is combined with another stimulus that
already elicits the CR
▫ Latent Inhibition
- Initial exposure to neutral stimulus without the UCS
slows later learning of CS-USC association and developing CR
Biological preparedness
Preparedness to learn
• Some associations are more easier learned than others
• Biologically wired readiness to learn some associations more easily than others
▫ E.g., land animals connect taste with nausea responses
Operant conditioning / instrumental conditioning
- Goal oriented behaviour
Operant conditioning: changes in behaviour that occur as a result of the consequences of the behaviour
• A form of learning in which voluntary responses come to be controlled by their consequences
▫ Operant responses (behaviours are voluntary in nature
▫ Emitted by the subject rather than elicited by the environment
Instrumental learning - Thorndike (1898 - 1911)
- Placed a hungry cat in a puzzle-box (cage) and a small
amount of food was placed just outside the door - To get to the food, the cat could open the door by pressing a lever
- Initially, the cats tried a number of behaviours to escape
before stumbling across correct response - Thorndike was interested in how long it took the cat to
escape when placed back in the box - DV = the latency (how long) for the cats to escape across a number of trials
Thorndike’s experiments
• Trial 1 - more than 150 seconds to escape • Trial 40 = 7 seconds • Behaviours that opened the door were followed by consequences (escape, food) • Operant conditioning – the organism’s behaviour changed because of the consequences that followed it * Argued that the behaviour was not insight or intelligence Intelligence would be knowing exactly what to do to get out after the "aha" moment of stumbling upon the lever - in reality it was a linear process of strengthening the desirable behaviours
Thorndike’s law of effect
Behaviours leading to a desired state of
affairs are strengthened, whereas those leading to an unsatisfactory state of affairs are weakened
B.F Skinner
the Skinner Box
• He devised methods that allowed the animal to repeat the operant response many times in the conditioning situation
• Studied lever pressing in rats & pecking in pigeons
• In Skinner’s experiments the DV = response rate (how many times the rat pressed the lever)
Skinner’s beliefs
- Respondent behaviour (reflexive)
- Operant behaviour (voluntary)
• Proposed that voluntary behaviours are controlled by their consequences (rather than by preceding stimuli)
Reinforcement
- An environmental stimulus that occurs after behaviour and increases the likelihood that the behaviour will occur in the future
- If the consequences that follow a behaviour are favourable, the tendency to repeat the behaviour is strengthened
Positive reinforcement
- The presentation of a pleasant stimulus after a behaviour makes the behaviour more likely to occur in the future
- The response is strengthened because it is followed by presentation of a rewarding stimulus
Negative reinforcement
Occurs when a response is strengthened because it is
followed by the removal of an aversive stimulus
- Removal of an unpleasant stimulus (taking a panadol to stop a headache)
Primary reinforcers
reinforcers that have innate reinforcing qualities. These kinds of reinforcers are not learned.
– Water, food, sleep, shelter, sex, and touch, among others, are primary reinforcers.
Secondary reinforcers
has no inherent value and only has reinforcing qualities when linked with a primary reinforcer.
– Praise, linked to affection, is one example of a secondary reinforcer, as when you called out “Great shot!” every time Joaquin made a goal.
Positive punishment
The presentation of an aversive stimulus after a behaviour reduces the likelihood of the behaviour occurring in the future – e.g. a speeding fine
- addition off a speeding fine makes it less likely you will speed again
Negative punishment
The removal of a pleasant stimulus after a behaviour
reduces the likelihood of the behaviour occurring in the future – e.g. removal of TV watching time
Issues with punishment
- Learner may not understand which behaviour is being punished.
- Learner may come to fear the ‘punisher’, rather than learn an association between the action and punishment .
- Punishment may not undo existing rewards for a behaviour. E.g., ‘acting out’ in class may result in punishment but peer approval (reinforcement)
- Punitive aggression may lead to future aggression
Punishment v Reinforcement
- Punishment of undesirable behaviours is not very effective in achieving disciplinary goals
- Reinforcing desirable behaviours is more effective
Acquisition and shaping - operant conditioning
• A procedure in which a complex behaviour is trained/taught by reinforcing closer and closer approximations of the desired response ▫ Training a dog to fetch the paper ▫ Teaching a child to tie shoelaces ▫ ‘Clicker’ training ▫ Only positive reinforcement
Extinction in operant conditioning
• Just like in classical conditioning, if the reinforcer stops then the response tendency will weaken and disappear
▫ Commencement of extinction is often accompanied by a gradual decline until the response rate is zero
Schedules of reinforcement
• The pattern of reinforcer (or punisher) delivery affects the pattern of responding
- continuous
- intermittent / partial
Continuous reinforcement
– Reinforcer is obtained after every response
– Good for training new behaviour
Intermittent / partial reinforcement
– Reinforcer is not obtained for every response
– More resistant to extinction, behaviour persists for longer
Ratio schedules
Interval schedules
Ratio schedules
▫ Fixed Ratio: Reinforced every nth response
▫ Variable Ratio: On average, reinforced after every nth
response.
Interval schedules
▫ Fixed Interval: Reinforced after specific time period has
elapsed
▫ Variable Interval: Reinforced after an average time
period has elapsed
Fixed interval schedules
• when behavior is rewarded after a set amount of time.
• This type of schedule exists in payment systems when someone is paid hourly:
▫ no matter how much work that person does in one hour (behavior), they will be paid the same amount (reinforcement).
Variable interval schedules
• subject gets the reinforcement based on varying and unpredictable amounts of time.
• People who like to fish experience this type of reinforcement schedule:
– on average, in the same location, you are likely to catch about the same number of fish in a given time period.
– However, you do not know exactly when those
catches will occur (reinforcement) within the time period spent fishing (behavior).
Fixed ratio schedules
• a set number of responses must occur before the behavior is rewarded.
• This can be seen in payment for work such as fruit picking:
▫ pickers are paid a certain amount (reinforcement) based on the amount they pick (behavior), which encourages them to pick faster in order to make more money.
Variable ratio schedule
• the number of responses needed for a reward varies.
• This is the most powerful type of intermittent
reinforcement schedule.
• In humans, this type of schedule is used by casinos
to attract gamblers:
– a slot machine pays out an average win ratio—say five
to one—but does not guarantee that every fifth bet (behavior) will be rewarded (reinforcement) with a win.
Applications of operant conditioning
Behavioural therapy: ▫ Reducing thumb sucking ▫ Reducing tantrums ▫ Quitting smoking Behavioural modification: ▫ Token economies ▫ Remedial education ▫ Therapy for autism (ABA; Applied behaviour analysis)
Seligman (1975) Learned helplessness
• The expectancy that one cannot escape aversive events
▫ As a result of this belief severely adverse effect on motivation and learning
• Seligman argued that learned helplessness is central to human depression
Seligman (1975) Learned helplessness
Day 1
Day 1
• Exp. Condition – dogs were harnessed so that they could not escape electric shocks
• The dogs eventually gave up
– Laid down, stopped struggling, showed signs of physiological distress
• Control condition – dogs were not exposed to inescapable shocks
Seligman (1975) Learned helplessness
Day 2
• Dogs were placed in shuttle box where escape was possible
• The dogs in the control condition learned how to escape
• Dogs in experimental condition
– Most did not attempt escape
– They had learned how to be helpless
Social learning
• Observational learning is learning by observing the behaviour of others (models).
• Imitation of a model’s behaviour depends on
▫ Prestige of the model
▫ Likeability and attractiveness of the model
▫ Whether the model was rewarded or punished for
his/her behaviour (vicarious conditioning)
Bandura BoBo Doll Experiment
Groups of children:
• Group 1 watched an adult acting aggressively towards a BoBo doll;
• Group 2 watched a video of an adult acting aggressively towards the doll;
• Group 3 watched a cartoon version
• Group 4 watched a non-aggressive model
• Group 5 saw no model
- the children either mimicked or did not mimic behaviour towards the doll based on whether the adults were rewarded or not rewarded for their actions
4 Key Processes
- ATTENTION to model’s behaviour and the consequences
- RETENTION of observed response in memory until a similar situation arises
- Ability to REPRODUCE the observed response
- MOTIVATION to reproduce the observed response
