Transcript 281 Lecture 8

Operant Conditioning
Shaping
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shaping = successive approximations toward
a goal
a process whereby reinforcements are given
for behavior directed toward a goal
reinforcement is given for approximations
toward a desired goal
Types of Shaping
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1) topographical shaping
the individual or organism did
not engage in the behavior
previously, but then is
reinforced for successive
approximations toward a goal
Types of Shaping
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2) quantitative shaping: here reinforcement is dependent on
either increasing or decreasing the quantity of some behavior
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an adjusting schedule of reinforcement
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a new response is not learned
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the individual already is engaging in the behavior and you either
want to increase or decrease it via shaping
Making Shaping Effective
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1)
2)
3)
4)
Define the goal
Determine a starting point
Pick a reinforcer
Determine the steps
Dissociative Identity Disorder
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What is DID? - replace MPD
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two or more distinct identities
at least two of these personalities take control of
behavior
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unable to recall important information
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not due to medical or substance
Dissociative Identity Disorder
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some alters are aware of others, some are not
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the host is the primary identity (the person)
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the alters can be the exact opposite of the host
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e.g., host = passive, alters = aggressive
handwriting and drawing is different
Dissociative Identity
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recognized since 1800s
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Benjamin Rush described DID
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Included in DSM-III for first time,
set stage for clinical research
Explanations for DID?
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True disorder
Another disorder
Possession
Iatrogenically induced disorder
Shaping and DID
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Condition 1 (C1)
Increased attention (e.g., media, research) to DID.
Condition 2 (C2)
Therapist strongly believes in the existence of DID.
Therapist is fascinated by the dissociative experience.
Condition 3 (C3)
Patient is psychologically fragile.
Patient believes the therapist is competent.
Patient is highly suggestible and or personality disordered.
DID symptoms = C1 * C2 * C3
Schedules of reinforcement
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1. Continuous (CRF)
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good to start with when shaping behavior
2. Non continuous (intermittent, partial)
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is one in which only some responses are
reinforced
four basic types
Intermittent Reinforcement
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1. Fixed Ratio (FR): reinforcement delivered after
fixed number of correct responses.
e.g., FR 3 = 3 responses to get reinforcer
period of steady, rapid rate of responding until
reinforcement, then a brief pause before starting
again
low resistance to extinction
PRP longer with lean reinforcement (i.e., FR 100 v FR 3)
Post reinforcement pause (PRP)
Ratio strain = too much responding required, behavior stops.
Fixed Ratio
Intermittent Reinforcement
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2. Fixed Interval: Reinforcement for next
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initially, a slow rate of responding, gradually
increasing to rapid responding
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pause after reinforcement
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low resistance to extinction
correct response after a fixed amount of time
since last reinforcement.
Fixed Interval
Intermittent Reinforcement
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3. Variable Ratio: reinforcement after
varying number of correct responses
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moderate levels of responding with little
or no pause.
high resistance to extinction
Variable Ratio
Variable Ratio
Initially…
interaction
“good behavior”
victim
lots of positive reinforcement
victimizer
Abusive Relationships
Later…
Little positive
reinforcement
interaction
Lots of good behavior
victim
victimizer
stretching the ratio
Intermittent Reinforcement
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4. Variable Interval: reinforcement
after varying time since the last
reinforcement.
moderate levels of responding with little
or no pause
high resistance to extinction
Variable Interval
Mixed Schedules
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Fixed Duration (FD)
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The behavior must be performed
continuously for a fixed predictable
amount of time.
Variable Duration (VD)
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The behavior must be performed
continuously for a varying,
unpredictable amount of time.
DRL
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Differential Reinforcement of Low Rate Behaviour
Reinforcement is delivered after
individual behaves undesirably to a
lower rate than their normal rate for
that behaviour
DRL Example
DRH
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Differential Reinforcement of High Rate of Behaviour
Reinforcement for responding above a
specified level.
DRH Examples
DRP
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Differential Reinforcement of Paced Responding
Reinforced for an amount below and
above a certain range.
DRP Example
Intermittent Reinforcement
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Can you come up with examples of
each type of intermittent reinforcement
(FR, VR, FI, VI) DRP, DRL, and DRH?
Get together in groups and come up
with some examples.
DRO
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Differential Reinforcement of Zero Behavior
Delivery of a reinforcer for not engaging in a specific
behavior for a period of time.
DRO Application
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Define behavior to be changed.
Count frequency of behaviors in specified time frame.
The average is the interval for reinforcement.
If there are no behaviors during the period, reinforce.
If there are behaviors during the period, start the
timer again.
DRO Example
Temper Tantrums
DRI
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Differential Reinforcement of Incompatible Behaviour
An undesirable behaviour is weakened,
while a desirable behaviour is reinforced
DRI Example
Extinction
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1) B C
2) B  nothing
Result: decrease in B
Extinction
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B (tantrum)  C (being picked up/ attention)
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Problem:
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Positive reinforcement for the child: to continue
having tantrums.
Negative reinforcement for the parent: pick up
child: avoid tantrum
Called a Reinforcement Trap
Types of Extinction
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1. Social:
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e.g: telling jokes  no reinforcement =
no telling jokes
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2. Non Social:
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B  C (social reinforcement)
B  C (non social reinforcement)
e.g: looking at broken watch  no time
info. = stop looking at broken watch.
Side Effects of Extinction
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1.
2.
3.
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increase in variability
emotional behavior – frustration
aggression
resurgence
depression
A practical example of an extinction burst.
6. Behaviour that is
being extinguished
will get worse
(extinction burst)
before it gets better
Resistance to Extinction
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1. Schedule of reinforcement
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2. History of reinforcement
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Continuous versus intermittent
More reinforcement over time, the harder
to extinguish behavior
3. Magnitude of reinforcer
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Larger hard to extinguish
Resistance to Extinction
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4. Degree of Deprivation
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More deprived, greater resistance to
extinction
5. Previous experience
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With experience, extinction is quicker