Sensory and social reinforcement of head-turning in a profoundly retarded multiply handicapped child.

Head-turning by a nine-year-old multiply handicapped profoundly retarded child (highest item passed on the Mental Scale of the Bayley Infant development test: 2.6 months; highest item passed on Motor Scale of Infant development test: 0.1 month) was reinforced by a variety of potential reinforcers: auditory; vibratory; social; visual. In addition various elicitation and shaping procedures were employed. Relative to base-line performance only visual reinforcement produced a substantial increase in head-turning. This finding is discussed in terms of the compatibility of operant and reinforcer and is related to the recent literature on constraints and predispositions in learning. The extent to which visual reinforcement also had eliciting effects is considered and further experimental controls and operations described.