Operant Conditioning Part 2 Flashcards
Shaping
reinforcement of successive (closer and closer) approximations to the desired response. n Useful for complex behaviours n Used often with children
Process of shaping
Stage 1: specify the final desired behaviour
(e.g., young child to say ‘lip’).
n
Stage 2: identify a response to use as a
starting point (e.g., ‘L’ or ‘ips’)
n
Stage 3: reinforce the starting response and
then require closer and closer approximations
until the desired response eventually occurs.
what do we monitor in shaping
monitor rewards to determine whether behaviour is changing
Chaining
a series of discrete responses are interlinked
and culminate in a reinforcer.
behaviour is broken down into smaller components, with each positive response reinforced until the entire behavioural ‘chain’ is performed.
Segments of the chain are completed
Sequentially - linear
Cue
completion of one segment of the behaviour chain acts as a cue for the beginning of the next segment of the
behaviour chain.
a -> b –> c
Used to increase the frequency of behaviours
Examples of chaining
Forward chaining
Backward chaining
Forward chaining
chaining begins with the first element in the chain
and progresses to the last element.(e.g., Say, “ I’m”; Say, “I’m three”; Say, ”I’m three years”; Say, “I’m three years old”)
Backward chaining
Begins with the last element in the chain and
progresses to the first element.
helpful if low motivation.
Extinction
Basic processes:
occurs when the operant response
is no longer followed by a reinforcer.
response becomes weaker and
eventually disappears.
Resistance to extinction
responses continue
even when reinforcement has ceased.
Spontaneous recovery
sudden reappearance of a learned response
following extinction.
‘let’s try just one last time!’
in the absence of reinforcement, behaviour
soon drops out again.
Example of resistance to extinction
Child called out for his parents (Williams, 1959).
Whenever the parents responded they reinforced
the unwanted behaviour.
Parents were instructed to leave the room once the
child had been put to bed and not return.
Some resistance to extinction (continued crying)
but steady reduction in duration of tantrum
example of spontaneous recovery
Week 2: tantrums recovered spontaneously.
Crying was inadvertently reinforced by a
visitor who responded to the child’s distress.
Another week of consistent extinction
was successful.
Generalisation
a behaviour learnt in the
presence of certain stimuli also occurs for
similar stimuli;
‘ch’ example: ‘ch’ in chop pronounced ch …
generalise to chimp, chinchilla, etc. but may
pronounce ‘chored’ instead of ‘chord’ (cord).
Discrimination
behaviour is performed
in the presence of certain stimuli but not for
other cues.
Consequences must be…
Contingent on behaviour
Reinforcement / punishment is defined….
after the fact, in terms of their effects on behaviour
consequences need to be delivered…
promptly following a response
Premack principle
reinforcement hierarchy
a response can act as a reinforcer for any response
lower than itself on this hierarchy.
links less desirable with more desirable activities
n ‘If you eat your vegetables,
you may have dessert
Schedules of reinforcement
determine the frequency with which responses are reinforced
two main types of schedules:
Continuous reinforcement
- every instance of a behaviour is reinforced
Intermittent (or partial) reinforcement
- delivered only some of the time
greater resistance to extinction
Four types of intermittent schedules
fixed ratio
variable ratio
fixed interval
variable interval
fixed ratio
behaviour reinforced after a fixed number of non-reinforced responses
pick five apples and get $10
Variable ratio
reinforcement after a variable number of
non-reinforced responses.
number of non-reinforced responses varies
around a predetermined average (on average,
every nth response is reinforced).
Fixed interval
reinforcement is given for the first response
after a set period of time has elapsed.
variable interval
reinforcement occurs after a period of time has
elapsed but the time varies.
variable schedules
generate steadier responses rates and greater resistance to extinction
Relevance to communication
Speech offers verbal consequences
- powerful reinforcer (e.g., ‘good’, ‘well done’).
- may punish (‘that’s not a good answer’).
Speech is an operant
- ‘Please pass the sugar’
- My grandfather died and I had togo to his funeral’
Speech is a discriminative stimulus
- ‘Don’t touch that – it’s hot!’
- info about likely consequences.
