What Are Antecedent-Based Interventions?
Antecedent-based interventions (ABIs) are strategies that modify the environment or context before a target behavior occurs to prevent or reduce the likelihood of problem behavior. Unlike consequence-based procedures that address behavior after it happens, ABIs are proactive. They work by altering motivating operations, removing discriminative stimuli for problem behavior, or adding discriminative stimuli for appropriate behavior.
ABIs are particularly valuable because they prevent the problem behavior from occurring in the first place. This reduces the individual's exposure to negative experiences associated with the behavior, minimizes the need for reactive consequence-based strategies, and creates more opportunities for teaching and reinforcing appropriate alternatives. ABIs are considered a best-practice component of comprehensive behavior intervention plans.
Noncontingent Reinforcement (NCR)
Noncontingent reinforcement involves delivering the reinforcer that maintains the problem behavior on a fixed-time or variable-time schedule, independent of the individual's behavior. By providing free access to the reinforcer, NCR abolishes the motivating operation for the problem behavior. When the individual already has the reinforcer, there is less motivation to engage in problem behavior to obtain it.
How NCR Works
If a functional assessment reveals that a child's tantrums are maintained by attention, NCR would involve providing attention on a time-based schedule (for example, every 2 minutes) regardless of what the child is doing. Because the child receives frequent attention without needing to engage in tantrums, the value of attention as a reinforcer is temporarily reduced (an abolishing operation), and tantrums decrease.
Implementation Considerations
Begin with a dense schedule of reinforcement (frequent delivery) and gradually thin the schedule over time. If you start with a schedule that is too lean, the individual may still engage in problem behavior during the intervals between reinforcer deliveries. Monitor data carefully during the thinning process to ensure that problem behavior does not increase as the schedule is thinned.
High-Probability Instructional Sequence (High-P)
The high-probability (high-p) instructional sequence, also known as behavioral momentum, involves presenting a series of easy, high-probability requests (requests the individual is likely to comply with) immediately before presenting a low-probability request (a request the individual is likely to refuse). The momentum generated by compliance with the easy requests increases the likelihood of compliance with the more difficult request.
Example
Before asking a student to begin a difficult math worksheet (low-p), the teacher rapidly presents three high-p requests: "Give me a high five," "Tell me your name," "Touch your nose." The student complies with each high-p request and receives brief praise. The teacher then immediately presents the low-p request: "Please start your math worksheet." Research demonstrates that compliance with the low-p request is significantly higher following the high-p sequence than without it.
Key Guidelines
Present three to five high-p requests in rapid succession. Reinforce compliance with each high-p request briefly (praise or a brief social interaction). Deliver the low-p request immediately after the last high-p request, typically within 5 to 10 seconds. The momentum effect weakens with longer delays between the last high-p request and the low-p request.
Choice-Making
Providing choices is a simple but powerful antecedent intervention. When individuals are given a choice among tasks, materials, or the order of activities, problem behavior often decreases. Choice-making likely works by providing a degree of control over the environment and by allowing the individual to select the least aversive or most preferred option.
Choices can be offered in many forms: choosing which task to complete first, selecting from available materials, choosing where to sit, or deciding how to complete an assignment. Even limited choices (choosing between two options) can produce meaningful reductions in problem behavior and increases in engagement.
Environmental Arrangement
Environmental arrangement involves modifying the physical or social environment to reduce the likelihood of problem behavior. This can include removing or reducing access to stimuli that trigger problem behavior, increasing access to stimuli associated with appropriate behavior, and structuring the environment to promote success.
Examples of Environmental Arrangement
- Visual schedules - Provide predictability by showing the individual what activities are coming next, reducing anxiety and problem behavior related to transitions
- Seating arrangements - Move a student away from peers who trigger off-task behavior
- Material organization - Arrange work materials so they are easy to find and access, reducing frustration
- Transition supports - Use timers, warnings, and visual cues to signal upcoming transitions, reducing problem behavior during activity changes
- Stimulus removal - Remove distracting or triggering stimuli from the environment during instructional activities
Functional Communication Training as an Antecedent Strategy
While functional communication training (FCT) is primarily a consequence-based differential reinforcement procedure, the teaching component of FCT has antecedent properties. By establishing a communicative response in the individual's repertoire, you are changing the antecedent conditions so that the individual has an alternative behavior available in situations that previously occasioned problem behavior. The presence of a known, efficient communicative alternative alters the antecedent context for the individual.
Motivating Operations and ABIs
Understanding motivating operations (MOs) is central to designing effective ABIs. Motivating operations alter the value of a reinforcer and the frequency of behaviors that have been reinforced by that consequence. Establishing operations increase the value of a reinforcer, while abolishing operations decrease it.
Many ABIs work by manipulating motivating operations. NCR creates an abolishing operation by satiating the individual on the maintaining reinforcer. Providing choices may reduce the aversiveness of a task, serving as an abolishing operation for escape-maintained behavior. Offering preferred materials during instruction can create establishing operations for engagement and learning while simultaneously reducing the value of escape.
Combining ABIs with Consequence-Based Strategies
ABIs are most effective when combined with consequence-based strategies as part of a comprehensive behavior intervention plan. An ABI alone may not be sufficient to produce clinically significant and lasting behavior change, but it reduces the frequency of problem behavior so that consequence-based strategies (such as differential reinforcement and extinction) are needed less often. This combination creates a more positive, proactive treatment approach that aligns with ethical best practices and the principle of using the least restrictive effective intervention.
BCBA Exam Preparation
For the BCBA exam, be prepared to identify antecedent-based interventions from clinical descriptions, explain how each ABI works in terms of motivating operations and stimulus control, and select the most appropriate ABI for a given scenario based on the function of the problem behavior. Know the distinction between antecedent and consequence strategies and understand how they complement each other in comprehensive treatment plans.