Many behavior-reduction procedures, such as extinction and differential reinforcement, work through what happens after behavior. Antecedent strategies work earlier. They change what happens before behavior, so problem behavior is less likely to start at all. This lesson covers three you will often see in behavior plans: noncontingent reinforcement (NCR), high-probability request sequences, and demand fading.
Why it matters
Preventing problem behavior is usually kinder and safer than responding to it. If a learner gets plenty of attention for free, there is less reason to scream for it. If a hard task comes right after a few easy wins, refusing is less likely. Antecedent strategies also give learners more chances to contact reinforcement for appropriate behavior.
Your supervisor chooses the strategy, the reinforcer, and the schedule, usually based on a functional assessment. Your job is to run each step exactly as written and to collect accurate data. On the exam, expect scenarios that ask you to name the strategy, spot an implementation error, or tell NCR apart from a contingent procedure such as DRO.
Key ideas
- Antecedent strategies change the conditions before behavior. Many work by changing a motivating operation: they lower the value of the reinforcer that problem behavior produces, or make the demand less aversive.
- NCR delivers the reinforcer on a time schedule, not after a behavior. The learner gets the reinforcer every set amount of time, whatever they are doing. When the reinforcer matches the function (attention for attention-maintained behavior, breaks for escape-maintained behavior), the learner has less motivation to work for it through problem behavior, and problem behavior is no longer the only reliable way to get it.
- NCR starts rich and gets thinner. The first schedule is often dense, sometimes set from how often the behavior happened in baseline. Your supervisor thins it gradually as problem behavior stays low. You do not change the schedule on your own.
- A high-p sequence builds momentum toward a hard request. You give a short run of quick, easy requests the learner almost always follows (often about three), reinforce each one, and then present the harder request right away. This is also called a behavioral momentum intervention.
- Demand fading lowers demands, then brings them back slowly. The plan starts with few or no demands and adds them back in small steps while problem behavior stays low. It is mainly used for escape-maintained behavior and is often paired with other procedures, such as extinction.
Definitions
- Antecedent intervention: any change to the environment before behavior that makes problem behavior less likely or appropriate behavior more likely.
- Noncontingent reinforcement (NCR): delivering a reinforcer on a fixed-time (FT) or variable-time (VT) schedule, independent of the learner's behavior.
- Fixed-time (FT) schedule: the reinforcer is delivered when a set time passes, with no response required. Compare a fixed-interval (FI) schedule, where a response is required after the time passes.
- Variable-time (VT) schedule: the reinforcer is delivered after varying amounts of time around an average, with no response required. Compare a variable-interval (VI) schedule, where a response is required after the time passes.
- High-probability (high-p) request: an instruction the learner follows reliably and quickly. A low-probability (low-p) request is one they often do not follow.
- Demand fading: temporarily reducing or removing task demands, then gradually increasing them back toward typical levels.
Examples from a session
Three antecedent strategies in action
- NCR (clinic): Leo, age 5, yells to get adult attention. His plan says FT 2 minutes. Every time the timer vibrates, Priya gives him 10 seconds of friendly attention, whether he is building blocks or looking around the room.
- High-p sequence (school): Aaliyah, 12, often refuses "Start your journal." Her RBT, Marcus, says "High five," "Pass me the pencil," and "Point to the date," praising each quick response. Within a few seconds he says, "Now write your first sentence."
- Demand fading (vocational program): Jordan, 23, pushes materials away during packaging tasks to escape them. His plan starts at 2 items per work period and adds 1 item after 3 sessions in a row below the behavior criterion. His RBT, Sofia, follows each step and graphs the data so her supervisor can review it.
When a learner's data start to change, or a caregiver asks to speed things up, record what you see and tell your supervisor. Steps, schedules, and criteria are clinical decisions.
Common mistakes / exam traps
- Confusing NCR with DRO. NCR is time-based and ignores behavior. DRO delivers the reinforcer only if problem behavior did not occur during the interval, so it is contingent.
- Delivering NCR only when the learner is "being good." That turns it into a contingent procedure. Deliver on the clock as written.
- Accidental pairing. If a scheduled delivery lands right after problem behavior, it can strengthen that behavior by chance. Some plans tell you to wait a few seconds in that case; follow your plan.
- Using hard or new requests as "high-p." They only work if the learner already follows them almost every time.
- Waiting too long after the last high-p response. Momentum fades. Present the low-p request right away.
- Starting the high-p sequence after problem behavior. Switching to easy requests right after a learner screams can reinforce screaming by removing the hard demand. Use the sequence before the low-p request.
- Jumping demand-fading steps. Adding many tasks at once, or dropping back to zero without direction, breaks the plan.
Exam trap
Ask: does the learner have to do (or not do) something to get the reinforcer? If no, it is NCR. If the reinforcer depends on the absence of problem behavior, it is DRO.
Exam trap
High-p sequence or demand fading? A high-p sequence puts a few easy requests seconds before one hard request. Demand fading changes how much work the learner gets, adding it back step by step across sessions.
Quick check
Nia, age 7, often refuses to put her shoes on at home. Before asking, her RBT says 'Clap your hands,' 'Touch your head,' and 'Give me a fist bump,' praising each quick response, and then immediately says 'Put on your shoes.' Which strategy is this?