ABA Fundamentals

Lag Schedules and Functional Communication Training: Persistence of Mands and Relapse of Problem Behavior.

Falcomata et al. (2018) · Behavior modification 2018
★ The Verdict

Adding lag 1-5 to FCT keeps mands fresh and problem behavior gone.

✓ Read this if BCBAs doing FCT with autistic kids in clinic or home.
✗ Skip if Teams already using serial FCT with no resurgence issues.

01Research in Context

01

What this study did

Two boys with autism got FCT for problem behavior. One was 5, the other 7.

After they learned one mand, the team added a lag schedule. The boy now had to use a different word every 1-5 trials to get the toy.

02

What they found

Problem behavior stayed low even when the lag grew to 5. Mand variety stayed high.

One boy kept using new words even when lag dropped back to zero.

03

How this fits with other research

Lambert et al. (2017) tried serial FCT first. They taught three mands in order. Resurgence only shrank a little.

Stevens et al. (2018) beat that result. Lag schedules gave bigger, longer gains with less teaching time.

O'Reilly et al. (2012) put the mand before the tangible. That helps at the start. Lag schedules help later when you thin reinforcement.

04

Why it matters

If you run FCT, slip in a lag 1 after the first mand is solid. Grow the lag as you thin. You get two wins: the child keeps talking in new ways and problem behavior stays quiet even at lag 5. One child kept the skill after lag went to zero, so you may keep the schedule for just a few sessions.

Free CEUs

Want CEUs on This Topic?

The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.

Join Free →
→ Action — try this Monday

After the first mand hits 80 % for two days, start lag 1: require a new word every other trial.

02At a glance

Intervention
functional communication training
Design
single case other
Sample size
2
Population
autism spectrum disorder
Finding
positive
Magnitude
large

03Original abstract

We evaluated the effects of lag schedules of reinforcement and functional communication training (FCT) on mand variability and problem behavior in two children with autism spectrum disorder. Specifically, we implemented FCT with increasing lag schedules and compared its effects on problem behavior with baseline conditions. The results showed that both participants exhibited low rates of problem behavior during treatment relative to baseline during and following schedule thinning (up to a Lag 5 schedule arrangement). Variable and total mands remained high during schedule thinning. With one participant, variable manding persisted when the value of the lag schedule was reduced to zero. The current results are discussed in terms of implications for training multiple mand topographies during FCT for the potential prevention and/or mitigation of clinical relapse during challenges to treatment.

Behavior modification, 2018 · doi:10.1177/0145445517741475