Varying response effort in the treatment of pica maintained by automatic reinforcement.
Make pica harder to reach than safe alternatives and the behavior disappears.
01Research in Context
What this study did
Three children with developmental delay kept eating non-food items. The team made the kids reach farther or lift heavier lids to get the items. They also tested what happened when safe toys were easy or hard to reach.
Each child was watched alone in a room. Sessions rotated between easy, hard, and blocked access. The team counted how often pica happened in each setup.
What they found
When pica items took more work to grab, pica dropped fast. One child went from 20 bites per hour to zero. The same child kept eating when the lid stayed light.
If fun toys were easy to reach, pica stayed low even when the bad items were easy too. Making the toys harder to get let pica creep back up.
How this fits with other research
HOFFMAN et al. (1963) showed that conditioned suppression can last 2.5 years in pigeons. Both studies use extinction logic: take away the payoff and the behavior fades.
Madden et al. (2003) taught rats to stop cocaine pressing when extinction cues lit up. The pica study does the same thing with effort instead of lights.
Hart et al. (1974) found that tougher DRL schedules made rats switch to wheel running. The kids also swapped to easier play when pica cost too much work.
Why it matters
You can thin pica without punishment. Put the chalk, paper clips, or foam pieces in a heavy jar with a screw lid. Place a basket of safe chewables within easy reach. Check data for one week—most kids show a clear drop by day three.
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02At a glance
03Original abstract
Pica is a life-threatening behavior displayed by many individuals with developmental disabilities. In the current study, automatic reinforcement maintained the pica of 3 participants. Following functional analyses of pica, response-effort manipulations were conducted in which the effort to obtain pica or alternative items was varied systematically. Several general relations emerged as a result of the study. First, levels of pica were reduced relative to baseline when alternative items were available independent of the effort required to obtain alternative items or pica. Second, increasing the effort for alternative items resulted in increases in pica relative to when effort for alternative items was low. Third, increasing response effort for pica produced reductions in pica relative to baseline when alternative items were unavailable. Fourth, the highest levels of pica occurred when the effort to engage in pica was low or medium and no alternative items were available. These findings are discussed in terms of the relative effects of quality of reinforcement and response effort on behavior.
Journal of applied behavior analysis, 2002 · doi:10.1901/jaba.2002.35-233