Operant Conditioning (Week 5)

Reinforcer

Consequence following behaviour which increases the probability of the behaviour in the future

Skinner

• Rate of behaviour is controlled by the conditions

• the process

  1. A response tat produces a consequence

  2. Consequence serves to increase or decrease the probability of the response

  3. Discriminative stimulus preceding the response signals the consequence is available

  • e.g. rat presses lever → Receive food pellets → Rat is more likely to press the lever in the future

Discriminative stimulus

• Indicates response will be followed by a contingency

• set the occasion for

• e.g. light signals

Positive reinforcement

• Behaviour is strengthened because it is followed by a reinforcing or rewarding stimulus

• Adding to make something to make a behaviour happen more

Negative reinforcement

• Behaviour is strengthened because it is followed by the removal of an aversive stimuli

• Removing something bad to make a behaviour happen more

• e.g. taking an advil removes the aversive stimuli of a headache which increases your likelihood to take advil when you have a headache

Escape learning

learning of a response that allows a subject to escape an aversive stimulus

Avoidance learning

learning of a response that allows a subject to avoid an aversive stimulus

Primary reinforcer (intrinsic)

• unlearned inherently reinforcing because they satisfy a biological need

• e.g. food, water, warmth, sex

Secondary reinforcer (Extrinsic)

• Conditioned: that are learnt or become reinforcers after being associated with primary reinforcers

• e.g. money

Process

• Acquisition

  • the initial stage of learning

  • learning a pattern of responding or the association between behaviour and reinforcer

• Shaping

  • The reinforcement of closer and closer approximations of the desired behaviour

• Extinction

  • The gradual weakening and elimination of the response tendency

  • halting the reinforcement

Contingency

• the extent to which the behaviour and the consequence are correlated

• the stronger the relationship the more effective the reinforcer is likely to be

Contiguity

• the gap between a behaviour and its consequence

• if to long between there may be room for other behaviour to have occurred and what is learned then becomes confused

• learning can still occur despite delay

Reinforcer characteristics

• some work better than others

• the size and strength of the reinforcer can impact conditioning

• quality

• a large reinforcer is generally more effective than a small one

• frequent small reinforcements may work better

Behaviour characteristics

Certain aspects of behaviour may be easier to learn than others

Motivating operations

• anything that changes the effectiveness of a consequence either in terms of increasing/decreasing its effectiveness

• Establishing

  • increase the effectiveness of a consequence

• Abolishing

  • decrease the effectiveness of a consequence

Schedules of reinforcement

• Continuous

• Ratio

• Interval

• Duration

• Time

• Progressive

• Chained

• Multiple

Continuous reinforcement

• Every occurrence of the behaviour is followed by a reinforcer

• limited conditioning or shaping

Ratio schedules

occurance of the behaviour

Fixed and variable

Fixed ratio schedule

• reinforcement depend upon a fixed predictable number of responses emitted since the last response

• high rate of responding

• post-reinforcement lengths with task duration

• low resistance to extinction

Variable ratio schedule

• reinforcement depends upon a variable of unpredictable number of responses emitted since the last reinforcer

• results in high and steady response rate

• No post-reinforcement pause

• High resistance to extinction

• e.g. Poker machine

Interval schedule

after an amount of time fixed and variable

Fixed interval schedule

• A responses is reinforced when a fixed/predictable period of time has elapsed since the last reinforcer

• Scallop pattern of responding

• Post reinforcement pause

• Low resistance to extinction

Variable interval schedule

• A response is reinforced when period opf time has elapsed since the last reinforcer

• Moderate to steady rate of responding

• No post reinforcement pause

• High resistance to extinction

Extinction

• Non reinforcement of previously reinforced response, resulting in a decrease in response strength

• No more behaviour extinguished

• Side-effects

  • Extinction burst

    • Temporary increase in frequency and intensity of responding when implemented

  • Increase in variability

    • the way in which the behaviour occurs changes form

  • Emotional behaviour

    • frustration

  • Aggression

  • Resurgence

  • Depression

    • Reflect loss of reinforcement

  • Resistance

    1. Schedule

    2. History of reinforcement

    3. Magnitude of the reinforcer

    4. Degree of deprivation

    5. Previous experience

Enhancing

• Differential reinforce of other behaviour

• extinguish behaviour while giving reinforcement for an alternate

• No deprivation of reinforcement in the setting

Duration schedules

a behaviour must be performed continuously for a period of time

Time schedules

A reinforcer is delivered after a period of time regardless of what behaviour occurs

Progressive schedules

The requirement for the reinforcement increase in a predetermined way following each reinforcement

Chained schedules

• sequence of schedules in a specific order

• weaker responses earlier in chain

• long chains can be vulnerable to destruction

Multiple schedules

a mix of 2 or more simple schedules

Partial reinforcement effect

Intermittent and longer schedule is more resistant to extinction

• 4 hypotheses

  • Discrimination

    • extinction takes longer because it is harder to discriminate between an intermittent schedule and extinction

  • Frustration

    • non-reinforcement is frustrating

    • reducing this will be reinforcing

  • Sequential

    • two events of reinforcement/ no reinforcement

    • sequence becomes a signal for the behaviour

  • Response unit

    • the difference of behaviour during intermittent and continuous reinforcement

    • more effective as you have not taken into account the response unit

Punisher

Consequence following behaviour which decreases the probability of the behaviour in the future

Positive punishment

• giving a punisher to reduce behaviour

• i.e. hitting

Negative punishment

removing a pleasant stimuli to reduce a behaviour

Problems with punishment

1. What not to do not what to do

2. Escape or avoidance of the punishment

3. Aggression towards the punisher

4. Apathy of all behaviour

5. Abuse

6. Limitation of the punisher

7. Punishment of maladaptive behaviour

Benefits of punishment

• Increase in social behaviour

• improvement of mood

• increase attention to the environment

Appropriate use of punishment

• Immediate

• Consistent

• Intense enough

• Negative punishment is better

• Combined with explanation where possible

• Combined with a positive reinforcement for appropriate behaviour

Alternative\s to punishment

• response prevention

• extinction

• differential reinforcement

Variables affecting punishment

• contingency

• contiguity

• Intensity

• Introductory level of punisher

• Any reinforcers

• Alternate sources of reinforcements

• Motivating operations