Functional Communication Training (FCT) in ABA Therapy

When a child engages in challenging behaviors such as head-banging, physical aggression, or prolonged tantrums, caregivers may struggle to manage them safely and productively. Functional Communication Training (FCT) is a widely used, evidence-based ABA intervention that aims to reduce challenging behavior by teaching the child an alternative, effective way to communicate.

Teaching functional communication reduces problem behaviors by addressing their function. A behavior’s “function” is the reason a child engages in it. When children find it easier to communicate in socially appropriate ways, problem behaviors usually decrease.

In this article, we’ll examine the history and science of Functional Communication Training, the importance of Functional Behavior Assessments, and strategies for implementing FCT.

Foundations of Functional Communication Training

Functional Communication Training is based on the principles of Applied Behavior Analysis (ABA). ABA is a scientific approach to understanding behavior and its environmental influences. FCT was first described and named in a 1985 research article titled Reducing Behavior Problems Through Functional Communication Training (Carr & Durand, 1985).

The authors hypothesized that, at times, children’s behavior problems are nonverbal forms of communication. To reduce behavior problems, then, verbal forms of communication could be taught as replacements for nonverbal problem behaviors.

To test this hypothesis, the authors replicated the intervention across four children with developmental disabilities. In all four cases, teaching the children an equivalent form of verbal communication resulted in a significant decrease in challenging behavior. Since the study was published in the Journal of Applied Behavior Analysis in 1985, the results have been reliably replicated, and FCT remains a staple in the toolbox of ABA practitioners.

The core idea of FCT is to teach children to replace problem behaviors with socially acceptable forms of communication that address their needs. For example, if a child with autism hits his head to protest being told to stop using the iPad, teaching him to say “no,” “not yet,” or “more time, please” provides a more appropriate way to communicate.

In the example above, it’s important to reinforce and honor the child’s appropriate responses. If caregivers expect a child to engage in appropriate communication and still not receive what they want (e.g., more time on the iPad), then teaching FCT will not be effective. To increase the new skill of verbally protesting or asking for more time, it will need to be reliably reinforced at the beginning of FCT. Once the dangerous behavior of head-banging no longer occurs (or occurs very rarely), then the schedule of reinforcement can be faded. At that point, additional interventions can be implemented, such as priming for the transition away from the iPad using timers. All FCT should be tailored to the learner’s needs and abilities to ensure that the communication methods being taught fall within the child’s abilities.

The Role of Functional Behavior Assessment (FBA)

To identify an appropriate communication target for FCT, the function or cause of the child’s behavior problem must be determined. In order to identify the function of a particular behavior, BCBAs will conduct a Functional Behavior Assessment (FBA). Without a formal FBA, caregivers and professionals involved in the child’s life are only guessing at the cause of the behavior. Often, these guesses involve projections or narratives surrounding events that happened earlier in the day, or conjecture about a child’s thoughts or internal states. Sometimes these guesses may be correct or partially correct, but it’s essential to observe and record challenging behavior in the moment.

An FBA, or Functional Behavior Assessment, is typically conducted by a Board Certified Behavior Analyst (BCBA) or another qualified behavioral professional. An FBA is a structured process for identifying why a specific behavior occurs. The first step is to look at the sequence of events called antecedents (what comes before), the behavior itself, and the consequences (what happens after).

Identifying Antecedents: An antecedent is an observable event in the environment that occurs immediately before a child’s behavior. This could be a loud noise, the removal of access to a preferred item/activity, or the removal of attention from an adult (e.g., a teacher turning away to help another child). In short, it’s the events and circumstances happening around the child right before they start engaging in the behavior.

Identifying Challenging Behavior: Each behavior should have its own FBA, since different behaviors can be maintained by other functions (see below for the definition of functions). Each behavior should be observable and measurable, and it should be operationally defined. Observable and measurable means that everyone observing the behavior should be able to agree on what they witnessed, when it occurred, how many times it occurred, or for how long it happened. For example, the BCBA, teacher, and parent should all agree that a child engaged in head-banging three times during a particular session.

Identifying Consequences: In ABA terminology, the consequence of a behavior describes what happens immediately following a behavior. The consequence would need to be an observable behavior as well. Let’s say that a child, Joe, is working with his ABA therapist. His therapist is distracted by another child who needs help, so she turns away from Joe to help the child. Joe immediately begins banging his head against the ground, and his therapist immediately turns her attention back to him. In this case, the consequence (what happens immediately after the behavior) is that the therapist provides attention again when Joe starts head-banging.

This three-term contingency (also referred to as the A-B-C contingency) forms the basis for a functional behavior assessment. In addition to observing antecedents, behaviors, and consequences, the BCBA may also administer questionnaires with other caregivers to identify possible functions. These are typically done in an interview format with formal questionnaires, such as the FAST (Functional Analysis Screening Tool), the QABF (Questions About Behavioral Function), and others. Both the ABC analysis and questionnaires aim to determine the function, or reason, for a behavior.

The Four Functions of Behavior: In ABA, there are four identified functions of behavior: Attention, Escape, Access to Tangibles, and Sensory (or automatic). Essentially, if a child engages in a behavior for attention, we’d say the behavior’s function is attention. If a child engages in a behavior to escape a task demand or a specific scenario (e.g., eloping from circle time), the behavior’s function would be escape. Engaging in a tantrum to access an item or activity would be considered behavior maintained by access to tangibles, so the function would be access to tangibles. Sometimes children will engage in self-stimulatory behaviors without a clearly observable antecedent or consequence – in this case, the function of the behavior would be sensory.

After the BCBA makes a hypothesis about the likely function of a behavior, the results of the FBA will guide the BCBA’s selection of an effective FCT plan. Returning to the fictional example with Joe, let’s say that the BCBA completed the FBA and determined that the hypothesized function of Joe’s head-banging behavior is attention. From there, the BCBA would create a behavior plan incorporating FCT for attention. In other words, the BCBA and therapist would teach Joe to request attention from his therapist by tapping her shoulder, saying her name, or another appropriate bid for attention. The therapy team would consistently and immediately reinforce Joe’s appropriate requests for attention with much higher-quality attention than he receives when he engages in head-banging. However, some attention would be needed to ensure Joe’s safety, likely by blocking the behavior with a pillow. However, the therapist could attend to Joe’s safety without verbally responding or commenting, for example, to minimize the amount of attention received for head-banging while maximizing the amount of attention received for the appropriate bids for attention.

Implementing Functional Communication Training

When the BCBA completes the FBA, they’ll create a behavior plan based on the FBA results. The behavior plan is a written document that outlines the results of the FBA, the hypothesized functions of the target behavior, and strategies to help decrease the target behavior. The behavior plan typically includes several key features.

First, the BCBA must select an appropriate functional communication response to teach during FCT based on the learner’s abilities.  For example, children who don’t yet speak may not be able to use vocal-verbal functional communication, but they may be able to use sign language, gestures, PECS (Picture Exchange Communication System), or an AAC (Augmentative Alternative Communication) device.

Next, the BCBA will decide which procedures the team will use to teach the functional communication response during FCT. Common teaching procedures include prompting, modeling, and reinforcement to encourage the child to use the new functional communication response in everyday life.

Again, the BCBA should ensure that the new communication skill serves the same function as the old behavior. For example, if a child with autism begins head-banging against the table when it’s time to stop using his iPad, a more appropriate response would be to teach the child to say “no,” “not yet,” or “more time, please.” If the child sees that this new skill easily allows him to spend more time using the iPad, he will likely continue to communicate in this way.

In the example above, it’s essential to reinforce and honor the child’s appropriate responses. If caregivers expect a child to engage in appropriate communication and still not receive what they want (e.g., more time on the iPad), then teaching FCT will not be effective. To increase the new skill of verbally protesting or asking for more time, it will need to be reliably reinforced at the beginning of FCT. Once the dangerous behavior of head-banging no longer occurs (or occurs very rarely), then the schedule of reinforcement can be faded. At that point, additional interventions can be implemented, such as priming for the transition away from the iPad using timers.

Once the child begins using the appropriate functional communication response during therapy sessions, the ABA team should start generalizing this skill to parents, teachers, and other caregivers by teaching them to implement FCT at home and at school.

Tools and Resources for FCT

Standard tools used in FCT include PECS, AAC devices (e.g., Proloquo2Go, LAMP, TouchChat), single-button or multi-button speech devices, communication boards, and visual supports. These additional tools provide alternative ways to implement FCT for learners with limited vocal-verbal abilities. Often, these communication tools are used across disciplines, which can promote generalization across settings and people. Speech therapists also commonly use PECS and AAC devices, so it’s beneficial to collaborate with other professionals to ensure everyone implements FCT consistently. At times, obtaining an AAC device can be expensive, so it’s also helpful to see whether the child’s school or health insurance can help cover the cost.

If you’re a practitioner or beginner interested in diving in deeper with FCT, there are several easily accessible resources online from reputable sources:

For beginners, start with the Autism Internet Modules (AIM) — it’s self-paced, free, and covers foundational concepts.

If you are working in a school or team setting, consider structured workshops (such as Project ACCESS) and Organization for Autism Research (OAR) webinars to ensure everyone involved uses consistent procedures. (Please note that these online workshops may require some prior knowledge.)

FCT Tips for Families and Caregivers

Families also play an essential role in teaching their child to use functional communication at home. Talk with your BCBA and schedule a time for them to teach you how to implement FCT at home, as it’s one of the best tools for safely addressing challenging behavior. A few tips to remember as you start implementing FCT:

• Create opportunities to practice FCT in daily life.
• Reinforce the new communication skill every time it’s first introduced.
• Keep PECS or AAC devices readily available for easy access.
• Model and prompt the new communication skill frequently.
• Practice FCT during natural routines (mealtime, playtime, transitions).

Practical Considerations and Common Challenges

Although the concept of FCT is simple – replace challenging behaviors with communication skills that serve the same purpose – practitioners may run into barriers with implementation. Common obstacles in FCT implementation include:

• Inconsistent reinforcement: For the child to learn that the functional communication skill works, every response needs to be reinforced at the start of treatment. What this looks like is therapists and caregivers have to honor the child’s response in the beginning, every time it happens. For example, if a child is working on manding for goldfish crackers by signing “more,” then each sign should be immediately reinforced by providing a cracker right after the child signs. If reinforcement is delayed or absent, the child may resort to the original problem behavior.
• Overgeneralization of functional communication responses: Sometimes, a child may learn one specific communication skill, such as signing “more” during snack time. If it’s the only form of communication the child has learned, then they may start using that sign in a variety of situations when they’re trying to communicate something, even when it doesn’t make sense to request “more” in those contexts (e.g., signing for “more” when they’re crying because they’re feeling tired). Because of this, a variety of communication skills should be taught and implemented in different scenarios and environments so that the child learns which functional communication responses to use and when, depending on the context.
• Lack of appropriate caregiver/staff training: If the professionals and caregivers in a child’s life aren’t trained to implement FCT correctly, the child may not learn that functional communication is a reliable means of communication; this may then lead to a resurgence of maladaptive behaviors. To prevent this, there are a few key skills that are very important for staff and caregivers to learn:

1) How to model and prompt the functional communication response during the teaching phase

2) How to safely and appropriately block challenging behaviors if they do occur during FCT

3) How to deliver immediate reinforcement for appropriate responses

4) How to consistently reinforce appropriate communication responses every time at the start of FCT

5) How to differentially reinforce functional communication rather than the maladaptive behavior that you’re trying to replace

6) How to appropriately begin fading reinforcement after the child masters the skill

The most effective way to address all of these concerns is for caregivers and professionals to collaborate regularly, if not daily, on the child’s progress, technical questions about FCT implementation, and the need for additional staff training. It’s also equally important to celebrate the child’s wins as they successfully begin communicating safely and effectively.

Conclusión

Teaching new communication responses to replace challenging behavior provides a more ethical and humane approach than historical punishment-based approaches. Although FCT is a conceptually straightforward technology for teaching children with autism and developmental disabilities new behaviors to replace dangerous or harmful ones, it requires careful attention to the science behind FCT and proper staff and caregiver training to ensure treatment is effective.

FCT works best when implemented consistently across therapists, teachers, and caregivers. Ongoing training and collaboration are necessary to support the exciting new world that positive communication opens up for children.

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