3 - Learning (27.01.2020) Flashcards
Learning definition
“a process by which experience produces a relatively enduring change in an organism’s behavior or capabilities.”
Basic learning processes:
Non-associative learning – response to repeated stimuli
– Classical conditioning – Learning what events signal
– Operant conditioning - Learning one thing leads to another
– Observational learning – Learning from others
Habituation and Sensitisation
- Habituation is a decrease in the strength of a response to a repeated stimulus. (after a while you get used to the stimulus)
- Sensitisation is an increase in the strength of response to a repeated stimulus.
- Responses happen simultaneously and compete to determine behaviour
= 2 forms of non-associative learning
= this is true across the animal knigdom
Classical conditioning
- Pavlov (Nobel Prize in physiology, digestion)
Stimuli
• Unconditioned stimulus (UCS): A stimulus that elicits a reflexive or innate response (the UCR) without prior learning
• Conditioned stimulus (CS):
A stimulus that, through association with a UCS, comes to elicit a conditioned response similar to the original UCR
Responses
• Unconditioned response (UCR):
A reflexive or innate response that is elicited by a stimulus (the UCS) without prior learning
• Conditioned response (CR):
A response elicited by a conditioned stimulus.
When is classical conditioning strongest?
– There are repeated CS-UCS pairings
– The UCS is more intense (if the UCS is more intense you probably need less pairings)
– The sequence involves forward pairing (i.e. CS -> UCS)
– The time interval between the CS and UCS is short
Extinction of conditioning
- acquisition: CS - UCS pairing
- extinction is more like attenuation, establishing new patterns of learning
- reread this part!!
Stimulus generalisation
- A tendency to respond to stimuli that are similar, but not identical , to a conditioned stimulus.
- similar stimuli will also elicit the CR, but in a weaker form. e.g. the further away the frequency from original the less saliva production
Stimulus Discrimination
• The ability to respond differently to various stimuli.
– E.g. A child will respond differently to various bells (alarms, school, timer)
– A fear of dogs might only include certain breeds
– e.g. distinguish different sounds for different zoos and respond accordingly.
Clinical example of conditioning
- A significant proportion (25-30%) of patients undergoing chemotherapy experience anticipatory nausea and vomiting.
- Chemotherapy (UCS) -> Nausea (UCR)
- related cues e.g. sight of chemotherapy Unit (CS) -> anticipatory nausea
Also:
- hospital can be a conditioned stimulus of nausea
- immune system function of patients in hospital more suppressed than at home even though they did not have treatment yet.
- not only subjective effects!
Overshadowing
- Cancer patients divided into two groups
- Group one given unpleasant, novel drink
- Group two given water
- Patients in group one showed significantly reduced nausea to clinic setting alone i.e. the CS had been altered
=> the stimulus was shifted from the hospital setting to an unpleasant drink.
Classical conditioning and fear learning
- “Little Albert” Experiment (Watson & Raynor 1920)
- anything white and fluffy was scary (e.g. white cotton, bearded Santa Claus)
- result is string fear to rat, rabbit, dog and coat
- negative response to mask and Watson’s face.
Two-factor theory of maintenance of classically conditioned associations e.g. fear
- Trauma (UCS) & needle (CS) -> fear response (UCR)
avoid injections -> fear reduced -> tendency to avoid is reinforced
Menti 1
x
Menti 2
x
Thorndike’s Law of Effect:
A response followed by a satisfying
consequence will be more likely to
occur.
A response followed by an aversive consequence will become less likely to occur
Operant Conditioning
• Behaviour is learned and maintained by it’s consequences
•
Reinforcement
- there are different forms:
•Positive Reinforcement: occurs when a response is strengthened by the subsequent presentation of a reinforcer
– Primary Reinforcers: those needed for survival e.g. food, water, sleep, sex
– Secondary Reinforcers: stimuli that acquire reinforcing properties through their association with primary reinforcers e.g. money, praise
• Negative Reinforcement: occurs when a response is strengthened by the removal (or avoidance) of an aversive stimulus
– Negative Reinforcer: the aversive stimulus that is removed or avoided (e.g. the use of painkillers are
reinforced by removing pain)
• “Positive” and “Negative” refer to presentation or removal of a stimulus, not “good” and “bad”
Punishment
• Positive Punishment:
occurs when a response is weakened by the presentation of a stimulus (e.g. squirting a cat with water when it jumps on dining table)
• Negative Punishment: occurs when a response is weakened by the removal of a stimulus (e.g. phone confiscated)
Reinforcement vs Punishment
- Skinner maintained that reinforcement is a much more potent influence on behaviour than punishment
- Largely because punishment can only make certain responses less frequent – you cant teach new behaviour
- Implications for teaching and behaviour change?
Positive vs. negative (reinforcement, punishment)
refers to the presence of a stimulus.
Reinforcement schedules
How often and in what pattern does a stimulus have to appear for change?
• Continuous reinforcement produces more rapid learning than partial reinforcement
– The association between a behaviour and its consequences is easier to understand
• However, continuously reinforced responses extinguish more rapidly than partially reinforced responses
– The shift to no reinforcement is sudden and easier to understand
- variabel: e.g. every 5th time (or random number) most resistant to extinction
-> gambling!! this works by this schedule of reinforcement where sometimes you win sometimes you dint so you keep playing to seek that reinforcement.
Reinforcement schedules - specific
- Fixed interval schedule: reinforcement occurs after fixed time interval
- Variable interval schedule: the time interval varies at random around an average
- Fixed Ratio Schedule: reinforcement is given after a fixed number of responses
- Variable Ratio Schedule: reinforcement is given after a variable number of responses, all centered around an average
Operant Conditioning and health behaviour
- Chronic pain behaviour includes limping, grimacing, and medication requests.
- This is often reinforced by family or staff e.g. by being overly sympathetic, encouraging rest, increasing medication
- This behaviour is likewise reinforced by gratitude signals from the patient
- A cycle is created in which the patient receives positive consequences for “being in pain“, so pain is more likely to occur in frequency
Cognitive approach
- Unlike Skinner, Bandura believes that humans are active information processors and think about the relationship between their behaviour and its consequences.
- Social imitation may hasten or short-cut the acquisition of new behaviours without the necessity of reinforcing
Purely from social learning
Social Learning Theory
• Observational (vicarious) learning - We observe the behaviours of others and the consequences of those behaviours.
-> e.g. seeing someone else being reinforced for doing something on the ward round, change own behaviour.
• Vicarious reinforcement - If their behaviours are reinforced we tend to imitate the behaviours
Modeling or Observational Learning (Albert Bandura)
- Albert Bandura
- Occurs by watching and imitating actions of another person, or by noting consequences of a person’s actions
– Occurs before direct practice is allowed
Steps to Successful Modeling
– Pay attention to model
– Remember what was done
– Must be able to reproduce modeled behavior
– If successful or behavior is rewarded, behavior more likely to recur
Bobo doll experiment
- 72 children (Mean aged 4yrs) recruited from Stanford University Nursery.
- Bandura 1961
- All children spent time in a playroom with an adult who modelled either non- aggressive (building tinker toy) or aggressive play (punching and striking the Bobo doll with mallet)
- All children then spent a further 20 minutes in the room alone and their behaviour was observed. Aggressive behaviour both imitative and non- imitative was recorded.
- Children who observed aggressive behaviour showed a much higher level of aggression towards the doll.
Social Learning
• We don’t imitate the behaviour of everyone we encounter
• More likely if model is:
– Seen to be rewarded
– High status (e.g. Medical consultant) – Similar to us (e.g. colleagues)
– Friendly (e.g. peers)
