Lecture 4 - Stimulus control + discrimination Flashcards
What is an antecedent?
Events or stimuli that precede a particular behaviour. They precede an operant response.
Factors of antecedents
Antecedents can involve any of our senses
- touch, taste, smell, hear, see
Antecedents can also differ from person to person.
- I.e the antecedent of the smell of coffee may make Sav go into a coffee shop but not Bea as Bea does not drink coffee
Antecedents can be covert or overt
- I.e experiencing greif which leads to me internally feeling sad(covert), may have a specific impact on a certain behaviour.
COVERT = visible to only 1 person (internal state)
OVERT = visible to everyone
Antecedents can be distal or immediate
DISTAL = happened in the past but still has an effect
IMMEDIATE = current
What is stimulus control?
A behaviour is said to be under stimulus control
when there is an increased probability that the behaviour will occur in the prescence of a specific antecedent stimulus (Dinsmoor, 1995) - the extent to which a given stimulus determines the probability that a conditioned response will occur
Example of stimulus control
- opening the door on when hearing the doorbell .
- answering a call when the phone rings.
What happens if an antecedent is controlling our behaviour strongly?
Our behaviour will occur in response to that antecedent consistently. Everytime the cue is present (antecedent), a particular behaviour will follow.
The stronger that particular antecedent controls that behaviour, the more likely that the behaviour always occurs in prescence of that cue.
What are the two important terms when we talk about stimulus control?
- Discriminative Stimulus
- Stimulus Delta
What is Discriminative Stimulus?
The SD
- This is the antecedent stimulus that is present when a behaviour is reinforced
- the stimulus which signals the availability of reinforcers
E.g., When the traffic light turns green, drivers keep their car going forward, but not when the light turns red
Give me an example of an SD
- Green traffic light (for the behaviour of driving)
- Phone ringing (for the behaviour of picking up the phone)
What is the sequence of the dicriminative stimulus?
SD-> Behaviour -> SR
(SR = reinforcement)
What is the Stimulus Delta?
Stimulus in the prescence of which a behaviour is not reinforced
When the antecedent is present, if the behaviour was to occur, there would be no reinforcement that follows that behaviour
A stimulus in the environment that signals the non-availability of reinforcement
For example, you can normally ask questions in class but if teacher says please hold your questions until the end of the lesson, by raising your hand you will not be reinforced for this
Give me an example of S^
Picking up the phone and putting it to my ear only gets reinforced when the phone is ringing. So if i want to speak to someone, the phone needs to ring.
The reinforcemnet of speaking to someone isnt present if the phone isnt ringing
What is the sequence of the S^?
S^ -> Behaviour -> No SR
Another word for S^
Discriminative stimulus for punishment = stimulus Delta
S^ and its link to extinction and punishment
in the presence of S^, a behaviour occurs, there is no reinforcement available for the behaviour. This process could either be an extinction behaviour OR a punishment procedure (depends on consequence)
Stimulus control in every day life
Stimulus control plays a fundamental role in everyday life because it teaches us what behaviours will work depending on the context/circumstances in which they occur.
Which behaviours occur only in specific situations or circumstances?
- depends on the people around (father may be SD, while mother is S^)
- depends on the location (a shop in majorca is SD for buying alcohol at age 17, a shop in UK is S^ for buying alcohol at age 17)
Real life applications to Stimulus control
Keller and Scoenfeld
- developed a procedure to train soldiers in Morse Code during WW2.
Prior intervention, soldiers were given lists of alphabets with corresponding morse code. They were trained in the traditional approach by which they had to memorise the alphabet and the morse code through repetition.
Keller devised the cold voice method as an alternative to the traditional approach.
- He created a system where every recruit would hear the morse code, and they would have to write down the signal played.
- Immediately after the signal, the voice in the headphones would give a correct response “A”.
Written answer, if the answer was correct - this is immediate reinforcement
What is Discrimination training?
When we want behaviour to be under stimulus control and we are attempting to teach/learn that particular contingency (where behaviour in the presence of the SD gets reinforced)
Requirements of discrimination training
requires 1 behaviour (the behaviour that get reinforced) and 2 antecedent stimulus controls (the SD and the S^)
Keintz et al., (2011) study of discrimination training with coins
- Aimed to teach children with intellectual disabilities math skills with coins
- Children were given an instruction (e.g. “point to 5 cents”), and then three coins would be presented infront of the child: onedime, five cents and one cent.
- Child then gets an opportunity to respond.
In this scenario, the instruction of “point to five cents” is the SD (the stimulus that signals the availability of the reinforcement). If the instruction for “point to 1 cent”, was then displayed this would be the S^ for the behaviour of pointing to 5 cents.
This study was effective. Children learned to select the correct coin to the printed number.
Take home message from Keintz et al., (2011) study
- When DT is carried out, we have 1 behaviour and 2 conditions (SD and S^).
- In the presence of the SD, engaging in the behaviour is met with reinforcment. In the presence of the S^, engaging in the behaviour is not met with reinforcment. Typically, we never just train one behaviour.
- In this example, there are 3 behaviour that are being trained under different antecedents conditions
When stimulus control is in effect… (4 responses)
- The person responds to the SD promptly every time it is given
- You don’t see the behaviour in response to some other SD
- You dont get the behaviour in the absence of the SD
- You dont get some other behaviour in response to the SD.
Is the S^ the same as an extinction process?
Behaviour in the presence of S^ doesn’t get reinforced, so could either be an extinction process or punishment process - depends on CONSEQUENCE
Lets say I gave you foreign words. I told you to say hello to one word, and to wave on the second word (think of the example in the lecture), HOW DID YOU LEARN THESE WORDS? - how did you learn the contingency that every time we see the first word you say hello and the second word we wave?
- we were paying attention to the words on the screen
- the training stimuli was prominent (there was not a distracting environment, so high salience)
- Prompts “When you see this word, ild like you to wave”
- Reinforcement “well done” when we got it right
What are prompts?
Prompts are supplementary stimuli given BEFORE/DURING the performance of a behaviour, that increases the liklihood that the person will engage in the correct behaviour at the correct time
They offer a means to transfer stimulus control
Prompt & SD -> Behaviour -> SR
Types of prompts
Response prompts
* Verbal prompts
* modelling
* physical guidance
Stimulus prompts
* movement prompts
* position prompts
* redundancy prompts
What is a response prompt?
Any prompt that is provided IN ADDITION to a discriminative stimulus. The target of a response prompt is to induce the target behaviour
* verbal prompt: “when you see this, do that”
* modelling: e.g. watching a youtube video to show you how to put together a peice of furniture, you then go off and build the furniture based on the video
* physical guidance: holding someones hand while they learn to write their name
* gentural prompt: pointing to a sign
What is a stimulus prompt? (type of prompt)
When the stimulus itself is modified in someway
* Movement prompts: e.g. learning to discriminate between two different types of words, shaking the correct stimuli of the translation
* Position prompts: always putting the correct card closer to you
* Redundancy prompt: changing the colour, size or shape of the stimuli
Things to consider when providing stimulus prompts
A stimulus prompt may involve a change of the SD or the S^. When you change the S^ it may make the SD more salient.
* For example, reducing size of S^ stimuli and increasing size of SD stimuli
What is prompt fading?
Fading is one way to transfer stimulus control from the prompts to the SD.
Once behaviour is stable, then we start removing the prompts that we provided. So, we want to transfer the control back from the prompt to the SD.
Prompt fading techniques
Most-to-least
least-to-most
Time delay
What is Most-to-least prompt fading?
- Decreasing assistance. We provide as much assistance as possible at first and then we slowly decrease the assistance as the learner gets more and more comfortable engaging in that behaviour.
- It can be decreased by chnaging the type of prompt (hand holding, to shoulder rub, to thumbs up, to nothing)
What is the Least-to-most prompt fading?
- Only provide assistance when absolutely neccesary.
- In an example of writing their name, you at first give them a piece of paper and tell them to write their name, you see them struggling so you explain that you are going to write how you would write their name (if their name is ‘Tom’, you write ‘Tom’ on another piece of paper). If they are still struggling to write their name you could place a hand on their shoulder - working up, Least to most
What is Time Delay prompt fading? (x2 sub-types?)
The time difference between when a discriminative stimulus (SD) is presented and when the prompt is present
* Constant prompt delay - Prompt provided in supplement/addition to SD (If I were to always to provide assistance in 3 seconds)
* Progressive prompt delay - stimulus itself is changed/modified in some way
- e.g., increase the duration of the delay between the SD and the prompt. (Trial one, there might be a zero second delay (as soon as the word is put up I say “wave”). Then in the next trial, there might be 1 second delay (as soon as the word is put up, I wait one second then say “wave”) etc.. There is a 1 second increment that we wait with every passing prompt.)
O’Neil et al., (2022) Time delay prompting and fading
They had 4 children with complex educational needs. Researchers were training these children to recognize flags. They would present one flag at a time and the child had to identify which country the flag belonged to.
* The purpose of the study was to compare different types of prompt delay procedure.
compared progressive prompt delay and constant prompt delay.
They found individual differences in prompt preferences to transfer control back onto the SD depending on the participant
