Sensory reinforcement and contingency awareness of profoundly retarded children.

In two experiments, three of four profoundly retarded and physically handicapped children with MAs below 7 months demonstrated instrumental learning of a manipulatory response that produced either illumination or music. Discrimination of response-dependent from response-independent stimulation was demonstrated by the three subjects. Further, changes in two categories of collateral behavior, vacalizing and smiling, seemed to reflect recognition of changes in stimulus conditions. Results indicated that profoundly retarded children share with normally developing infants and children the capacity to be reinforced by sensory stimulation and to discriminate contingent from noncontingent events.