Treatment programs often utilize positive consequences to establish, increase, or maintain behavior. Recently, Dube and McIlvane (2002) examined the sensitivity of individuals with neurodevelopmental disabilities to differences in the frequency and magnitude of reinforcing consequences. Six individuals were exposed to a concurrent-choice procedure during which each option was associated with a range of schedules differing in reinforcer frequency or magnitude. Data were analyzed in accordance with the generalized matching law (Baum, 1974) and the positive slopes of obtained matching functions indicated sensitivity to the programmed reinforcer disparities.

In recent follow-up work, we have been using the methods of Dube and McIlvane (2002) to assess sensitivity to changes in reinforcer frequency in individuals at lower functioning levels. During pretraining, a number of our recent participants developed exclusive or near-exclusive stimulus preferences that have proven difficult to overcome. This “Research in Progress” report is intended to highlight this challenge, describe efforts to overcome it, and to report potentially promising remedial procedures.