Contingency Enhances Sensitivity to Loss in a Gambling Task with Diminishing Returns.

This study examined whether gambling behavior under conditions of diminishing returns differed between participants with histories of contingent (CD group) and noncontingent (NCD group) token delivery. In Phase 1, CD participants accrued tokens by correctly completing a discrimination task; for NCD participants, token accrual was yoked to token delivery of CD participants. In Phase 2, participants could choose to gamble their tokens or end the experiment and exchange their tokens for money.

Individualized sampling parameters for behavioral observations: enhancing the predictive validity of competing stimulus assessments.

Recent studies have used pretreatment analyses, termed competing stimulus assessments, to identify items that most effectively displace the aberrant behavior of individuals with developmental disabilities. In most studies, there appeared to have been no systematic basis for selecting the sampling period (ranging from 30 s to 10 min) in which items were assessed. Unfortunately, estimates based on brief samples of behavior do not always predict the extent to which items will displace aberrant behavior over longer periods.

Re-evaluation of constant versus varied punishers using empirically derived consequences.

Charlop, Burgio, Iwata, and Ivancic [J. Appl. Behav.

A comparison of dense-to-lean and fixed lean schedules of alternative reinforcement and extinction.

Behavior-reduction interventions typically employ dense schedules of alternative reinforcement in conjunction with operant extinction for problem behavior. After problem behavior is reduced in the initial treatment stages, schedule thinning is routinely conducted to make the intervention more practical in natural environments. In the current investigation, two methods for thinning alternative reinforcement schedules were compared for 3 clients who exhibited severe problem behavior.

Assessing psychopathology in individuals with developmental disabilities.

Individuals with developmental disabilities are at high risk for developing mental health problems. The prevalence of psychopathology is approximately 4 times higher than that found in the general population. Yet there is a tendency to underdiagnose psychiatric disorders in the developmentally delayed population because of diagnostic overshadowing, the lack of appropriate diagnostic criteria, and the paucity of appropriate assessment measures.