50
60
70
80
90
100
What environmental events?
• Very remote (in time) events {PAST}
– Natural selection
• Semi-remote events {PAST}
– Contingencies (respondent and operant)
• Current events {PRESENT}
– Presentation of stimuli (US, CS, SD, SD)
– Motivational & emotional operations
Chapter 20
Behavioral Chains
Behavioral Chain
• A sequence of stimuli and
responses.
• Each response produces a
change in the environment
that acts as a discriminative
stimulus (SD) for the next
response.
“….behavior does not occur as random strings
of unrelated responses but in organized
sequences, called chains, in which each
successive response produces the stimuli,
internal or external, that determine what
comes next. And when the time arrives to
initiate a new sequence of behavior, that, too,
is signaled by a change in stimulus
conditions.”
(Dinsmoor, 1995)
Task Analysis
A task analysis is
– an analysis of complex behavior and
sequences (chains) of behavior into
component responses.
TASK ANALYSIS
1.
2.
3.
4.
5.
6.
7.
Pick up fork
Spear potato
Lift fork to mouth
Open mouth
Place fork in mouth
Close mouth
Pull fork from mouth
Dual Functioning Chained Stimuli
• A stimulus in a behavior chain reinforces
the response that precedes it.
• That stimulus also acts as an SD or
operandum for the response that follows it.
SD
Dual-Functioning Chained Stimuli
Sight of
potatoes
Beh
Pick up
fork
Sr Oper.
Fork in
hand
Behavior
Sr/SD
Put fork in
potato
Fork in
potato
Behavior
Sr/SD
Raise fork
Fork raised
Behavior
Put potato
in mouth
Dual Functioning Chained Stimuli
• A stimulus in a behavior chain reinforces
the response that precedes it.
• That stimulus also acts as an SD or
operandum for the response that follows it.
Behavior
Sr/SD
Pull chain
Light on
Behavior
Sr/SD
Press
lever
Dipper click
Behavior
Approaches
dipper
Sr
Water
SD
Behavior
After/Sr/SD
Before
Light on
Behavior
After/Sr/SD
Before
Behavior
Before
After/Sr
Water
Forward Chain
• The establishment of the first link in a
behavioral chain, with the addition of
successive links, until the final link in
acquired.
SD
Sight of
potatoes
Beh
Pick up
fork
Train this link first
Sr Oper.
Fork in
hand
Behavior
Sr/SD
Put fork in
potato
Fork in
potato
Train this
link second
Behavior
Sr/SD
Raise fork
Fork raised
Behavior
FORWARD CHAINING
Put potato
in mouth
Total Task
• The simultaneous training of all links in a
behavioral chain.
Total Task
Training Links
Each one of
the hand
washing steps
Training Tools
Physical
guidance
Verbal
Instruction
Praise
Modeling
Results
Each one of
the hand
washing steps
Backward Chaining
• The establishment of the final link in a
behavioral chain, with the addition of
preceding links until the first link is
acquired.
23
x 42
46
920
???
BACKWARD CHAINING
23
x 42
46
???
???
BACKWARD CHAINING