Understanding Stimulus Control Transfer in Applied Behavioral Analysis

In ABA, therapists use stimulus transfer control to help patients develop new skills and overcome maladaptive behaviors, says Ian Jackson, a licensed mental health counselor and clinical director at Recovery Unplugged in Austin, TX.

“By using prompts, cues, and reinforcement, they gradually transfer control from the initial stimulus to a new one,” he notes.

How it works

Carrie Woodward, a board-certified behavior analyst in Long Beach, CA, who provides parent education and training on ABA, says behavior analysts evaluate behavior based on what variables (events, stimuli) precede behavior (antecedents), and what variables follow behavior (consequences).

The antecedent stimuli are said to “evoke” or “control” the behavior that follows, when the relationship is reliable.

“In other words, when you see a picture of a cow (antecedent stimulus), you say ‘cow,’ (behavior),” Woodward explains. “We would say that the picture of the cow ‘controls’ the response of saying ‘cow.’”

Often, behavior can come under the control of the wrong stimulus. In this case, behavior analysts need to work on transferring stimulus control from the wrong stimulus to the right stimulus, says Woodward.

So in the example of the cow, if a person looks at a picture of a cat and says, ‘cow,’ reliably, then the response of ‘cow’ is controlled by the picture of the cat, which is obviously wrong.

The therapist would then work to transfer control of saying ‘cow’ from the cat picture to the cow picture.

There are 3 types of procedures therapists use to transfer stimulus control:

• Prompt fading: The therapist identifies a prompt or cue that successfully controls the desired response. They use that prompt in addition to the stimulus they hope to control the response. They then gradually fade out the prompt by using less and less of it with each trial.
• Prompt delay: The therapist systematically delays the prompt with each trial.
• Stimulus fading: The therapist embeds prompts in the teaching materials they are using. They gradually reduce the presence of the initial prompt while increasing the presence of the new controlling stimulus.

Woodward shares the following examples of stimulus control transfer for each type of procedure:

1. Prompt fading

One example of prompt fading is teaching a child to clap their hands when they hear the instruction, “clap.”

At the start, the word “clap” does not exert stimulus control over the behavior of clapping. But the child can imitate, and so when you clap your hands, the child will clap their hands. You pair the word “clap” with the model prompts of clapping in order to evoke the behavior of clapping. For example, you may do this in four trials:

• Trial 1: say “clap” and fully model by clapping multiple times
• Trial 2: say “clap” and only clap once
• Trial 3: say “clap” and motion as if bringing our hands together to clap, but don’t actually clap them
• Trial 4: fade the model prompt entirely and simply say “clap”

You have successfully faded the model prompt, and transferred stimulus control from the model prompt to the auditory stimulus “clap.”

2. Prompt delay

Prompt delay may look like teaching a child to answer the question, “What is your name?”

Here, you can use an echoic prompt by verbally modeling the desired response. The child will then imitate you by saying the word. The stimulus you want to control the response is the question, “What is your name?”

At the start, there’s no stimulus control and therefore the child does not respond when they hear the question. But they can echo words, so you can model by saying, “Matt.” You should pair the question and the prompt with no delay to begin. For example, you may do this in three trials:

• Trial 1: you will begin by saying “What is your name? Matt.” The child will then say, “Matt.”
• Trial 2: insert a 1-second delay between the question and the prompt. “What is your name?” 1-second pause, “Matt.” Then the child will say, “Matt.”
• Trial 3: insert a 3-second delay, then a 5-second delay using the same prompt

Ideally, at a certain point, the child begins to answer before you have to provide the prompt. You have successfully transferred control from the echoic prompt to the question.

3. Stimulus fading

Teaching a child to read the word “car” by using a picture as the embedded prompt can be used for stimulus fading.

In picture 1, you can see the picture is embedded behind the word, and the car is very visible and obvious. When you show this to the child, they can say, “car” because the picture has stimulus control, not because they’re reading the word.

In picture 2, the car becomes less obvious. In picture 3, even more so, and by picture 4 you can only see the word.

At this stage, when the child sees the word car and can say, “car,” you have utilized stimulus fading to effectively transfer stimulus control from the picture to the word.

In addition to stimulus control transfer, ABA encompasses other techniques and strategies to help people develop new skills and modify their behaviors. Jackson highlights a few:

• Task analysis: Breaking down complex behaviors into smaller, manageable steps. This allows therapists to teach each step individually and systematically until the person can perform the entire behavior independently.
• Chaining: Teaching sequences of behaviors. This involves breaking down a specific task into smaller steps and teaching each step in order until the entire sequence is mastered.
• Modeling: Demonstrating a desired behavior for the patient to imitate. This can be especially useful for people who have difficulties with verbal communication or understanding instructions.
• Reinforcement: Using rewards or praise to increase or strengthen behavior.

Stimulus control transfer is a concept used in ABA, most often for people with ASD. It involves changing the prompt or cue that produces a certain behavior.

Behavior analysts use three procedures to help guide behavior:

• prompt fading
• prompt delay
• stimulus fading

When effective, stimulus control transfer can help reduce or eliminate behaviors of concern, promote independence, and improve lives.