This article reviews evidence from basic and translational research with pigeons and humans suggesting that the persistence of operant behavior depends on the contingency between stimuli and reinforcers, and considers some implications for clinical interventions. (Contains 4 figures.)

Derived conditional discrimination was evaluated in 2 men with mental retardation whose language was limited to gestural requests. In each conditional-discrimination task, sample stimuli were arbitrary visual forms and comparison stimuli were black squares presented in 2 of the 4 corners of a computer screen. Subjects learned to select 1 position…

To study improvement of visual monitoring of retardates, specialized training methods backed up by incentives were used. The extent to which these training techniques might be expected to produce results which would generalize was explored. Subjects were eight female mental retardates (ages 15-22) with IQs from 38 to 69. (Author/SJL)