PSYC 365: Unit 7

Chapters 9, 12, 13

three stages of a shaping procedure

1. specify the final target behaviour

2. identify a response that could be used as a starting point in working toward the final target behaviour

   1. reinforce the starting behaviour; then reinforce closer and closer approximations until eventually the final target behaviour occurs

shaping

the development of a new operant behaviour by the reinforcement of successive approximations of that behaviour and the extinction of earlier approximations of that behaviour until the new behaviour occurs

• also called: method of successive approximations

• shaping is a combination of positive reinforcement and extinction because achieving one stage then requires moving to the next which extinguishes prior behaviour

ex. “waa waa” → “watah” → “water”

topography

specific movements involved in the behaviour

ex. printing and writing, “daddy” instead of “dada”, dribbling a basketball (steps to learn how)

frequency

number of instances that a behaviour occurs in a given period of time

ex. number of steps, number of baskets in a hoop, increase time between bathroom visits

duration

the length of time it lasts

ex. time studying before a break, time at a center before changing activities

latency

time between the occurrence of a stimulus and the response evoked by that stimulus

• reaction time

ex. whistle blown to start a swimming race

intensity

force of a response

• physical effect the response has or potentially has on the environment

ex. how hard a ball is kicked, pushing a tire, shaking hands

dimensions of behaviour

topography, frequency, duration, latency, intensity

fading vs shaping

fading → involves reinforcing the same response in the presence of stimuli which increasingly resemble some end stimulus

shaping→ concerns itself with reinforcing successive approximations of a response toward some end response

factors that influence the effectiveness of shaping

• specifying the final target behaviour

  • all relevant characteristics of the behaviour are identified

  • conditions behaviour should or shouldn’t occur

  • guidelines

• choosing the starting behaviour

  • needs to occur often enough to be reinforced within the session time

  • should approximate target behaviour

• choosing the shaping steps

  • outline successive approximations moved through to reach the final target behaviour

• pace of movement through the shaping steps

  • how many times should each approximation be reinforced before moving to the next step

  • speed may need to be adjusted

what is meant by “starting behaviour” and “target behaviour”

should be a behaviour that occurs often enough to be reinforced within the session time, and it should approximate the final target behaviour

how shaping occurs in biofeedback procedures

• involves using technology to monitor and modify internal functioning

• modify internal functioning

• teach individuals with hypertension to reduce blood pressure under stressful conditions in a laboratory setting

fading

the gradual change over successive trials of an antecedent stimulus that controls a response so that the response eventually occurs to a partially changed or completely new antecedent stimulus

errorless discrimination training

the use of a fading procedure to establish a stimulus discrimination so that no errors occur

dimensions of a stimulus

Any characteristics of a stimulus that can be measured on some continuum

• fading occurs along a stimulus dimension through the strength of support being given starting stronger and gradually being decreased

ex. Pressure on another’s hand starting stronger and fading

final target stimulus

occurrence of the response to that stimulus is likely to be maintained in natural environment

starting stimulus prompt

supplemental antecedent stimulus provided to increase the likelihood that a desired behaviour will occur, but is not the final target stimulus to control that behaviour

within-stimulus prompt

a variation of the S^D or S^▲ to make their characteristics more noticeable and therefore easier to discriminate

ex. exaggerate part of a word

physical prompts

guiding the learning through touch

gestural prompts

motions that a teacher makes, such as pointing to a cue or making signals directed to the learner without touching

modelling prompts

occur when the correct behaviour is demonstrated

verbal prompts

spoken hints

environmental prompts

consists of alterations of the physical environment in a manner that will evoke the desired behaviour

extra-stimulus prompt

something that is added to the environment to make a correct response more likely

ex. pointing, placemat with utensils drawn on it

behavioural chain

also called: stimulus response chain

• a consistent sequence of stimuli and responses that occur closely to each other in time and in which the last response is typically followed by a reinforcer

ex. making a sandwich, getting dressed, brushing teeth

are all sequences behaviour chains?

no, because some sequences involve a variety of activities with breaks in the actions

• not a consistent series of stimuli and responses that occur closely in time

ex. studying, going to the store

total-task presentation (TTP)

an individual attempts all the steps from the beginning to the end of the chain on each trial and continues with total-task trials until the chain is learned

• prompting at each step as required

backward chaining (BC)

last step is taught first, then the next to last step is taught and linked to the last step, and so on, progressing backward toward the beginning of the chain

ex. dressing → putting on coat

forward chaining (FC)

teaches the initial step of the sequence first, then teaches and links together the first and second steps, and so on, until the entire chain is acquired

ex. toileting, brushing teeth, making a sandwhich

of the three methods for teaching behavioural chains, which is most appropriate for teaching people who have developmental disabilities?

• TTP is at least as good as, or better than, either BC or FC

• requires instructor to spend less time in partial assembly or disassembly to prepare the task for training

• focuses on teaching response topography and response sequence simultaneously → quicker results

• maximize learners independence early in training, especially if some steps are familiar to the learner

the three types of target behaviours learned through shaping, fading, and chaining

shaping → produce a new behaviour

fading → new stimulus control over a behaviour

chaining → a new sequence of stimulus — response steps

task analysis

the process of breaking down a task into smaller steps or component responses to facilitate training

• need to be simple enough to be learned without great difficulty

  • error and confusion are increased when similar stimuli are controlling different responses

self-instructions

written task analysis, picture prompts

adventitious chain

a behavioural chain that has at least one component that is not functional

ex. saying “like” or “uh”

ex. eating fast

ex. having to eat everything on plate

preliminary modelling trial

it may be desirable to start by modeling the entire sequence while verbally describing the performance of each step