6.2 Functional Communication Training (FCT), NCR, Setting Events & Antecedent Strategies

Functional Communication Training (FCT) and Antecedent Strategies

Functional Communication Training (FCT), originally formulated by Carr and Durand in 1985, is one of the most empirically validated behavioral interventions in applied behavior analysis. FCT operates as a specialized application of Differential Reinforcement of Alternative Behavior (DRA), in which a functionally equivalent communicative response is taught to replace challenging target behaviors. Rather than suppressing behavior through reactive consequences, FCT empowers the learner with an effective, socially valid communication system.

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1. Functional Communication Training (FCT) Protocols

FCT relies directly on the results of a prior Functional Behavior Assessment (FBA). If the FBA reveals that a client's aggressive behavior is maintained by negative reinforcement (escape from difficult tasks), FCT teaches a communicative response that produces escape (e.g., asking "Help please" or pressing an "I need a break" button).

[ Step 1: Conduct FBA ] ──► Identify Maintaining Function (Attention, Escape, Tangible, Automatic)
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[ Step 2: Select Modality ] ──► Match to Learner Repertoire & Listener Community
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[ Step 3: Dense FR1 Phase ] ──► Immediate, Continuous Reinforcement for Every Communication
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[ Step 4: Schedule Thinning ] ──► Systematically Introduce Delays, Ratios, or Visual SD/S-Delta Cues

Communication Modality Selection Criteria

Selecting the appropriate communication modality is vital for treatment success and maintenance. QBAs must evaluate three core criteria when selecting among vocal speech, manual sign language, Picture Exchange Communication System (PECS), or Augmentative and Alternative Communication (AAC) speech-generating devices:

1. Learner Motor and Cognitive Repertoire: The response must be already in or quickly acquired by the learner. If fine motor deficits impede sign language execution, PECS or a high-contrast AAC icon is preferred.
2. Response Efficiency: The communicative response must be faster and physically easier to produce than the target behavior. Complex multi-step navigation on a speech-generating device may fail if hitting a therapist is faster.
3. Community Legibility: Vocal speech and high-tech AAC devices with auditory output are universally understood by untrained listeners. Manual signs or specialized picture symbols require an educated listener community; if caregivers or peers cannot interpret the sign, the response will undergo unintended extinction.

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2. FCT Implementation Phases and Schedule Thinning

Phase 1: Initial Acquisition and Dense Reinforcement

During initial training, the replacement communicative response is placed on a Fixed-Ratio 1 (FR1) continuous reinforcement schedule. Every instance of the communicative response—even if fully prompted—must result in immediate, 100% delivery of the functional reinforcer with zero delay. Simultaneously, the problem behavior is subjected to function-based extinction.

Phase 2: Schedule Thinning Protocols

Once the communicative response is reliably established and problem behavior is low, clinicians must thin the reinforcement schedule to reflect naturalistic environment limits. Un-thinned FCT results in an unsustainable rate of requests (e.g., asking for a break every 10 seconds). QBAs utilize three primary schedule thinning procedures:

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3. Proactive Antecedent Strategies

While FCT teaches a functional replacement skill, antecedent strategies alter the environment or motivating operations (MOs) before problem behavior can occur, drastically reducing the likelihood of target behavior onset.

Noncontingent Reinforcement (NCR)

Noncontingent Reinforcement (NCR) involves delivering the maintaining reinforcer on a Fixed-Time (FT) or Variable-Time (VT) schedule, completely independent of the client’s behavior.

• Mechanisms: NCR functions as an abolishing operation (AO). By saturating the learner with attention, breaks, or tangibles at set intervals (e.g., 2 minutes of attention every 5 minutes), the value of the reinforcer drops, eliminating the motivation to engage in problem behavior to get it.
• Thinning NCR: Initial FT/VT schedules are set slightly denser than the baseline rate of problem behavior. The interval is gradually lengthened as target behavior remains low.

High-Probability (High-p) Request Sequence (Behavioral Momentum)

The High-Probability Request Sequence involves presenting 2 to 5 easy, high-compliance requests (tasks with a high historical probability of compliance) in rapid succession, reinforcing each quickly, and immediately presenting the low-probability (target) demand.

• Mechanism: Builds behavioral momentum, making compliance with the low-probability demand significantly more likely due to recent reinforcement history.

Demand Fading and Choice-Making

• Demand Fading: The clinician initially removes or substantially reduces task demands, then systematically reintroduces demand frequency, duration, or difficulty in small, tolerable increments.
• Choice-Making: Offering choices regarding task sequence, materials, seating, or reinforcers (e.g., "Do you want to do math first or reading first?") increases client autonomy, increases task engagement, and systematically decreases escape-motivated behaviors.

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Setting Events as Antecedent Interventions

Setting events are contextual or ecological conditions that alter the momentary probability of behavior by changing the value of reinforcers and punishers—even when the immediate SD looks unchanged. They sit “upstream” of the three-term contingency and often function like distant motivating operations or establishing contexts.

QBA application: Assess setting events during FBA (interview + ABC + medical review). When a setting event is present, intervene antecedently—change the ecology, thin demands, or increase access to competing reinforcers—before relying solely on consequence strategies. Document setting events on graphs as phase annotations so data interpretation is not misread as treatment failure.