Effects of vibratory, edible, and social reinforcement on performance of institutionalized mentally retarded individuals.

The relative effectiveness of verbal praise, vibration, and edible reward as methods of enhancing and maintaining performance on a perceptual-motor task was investigated. Sixty-six mentally retarded students were divided into high- and low-MA groups and randomly assigned to reinforcement conditions. Data analysis revealed that response rates for the low-MA students in the verbal condition reinforcement and the nonreinforcement phases were significantly lower than the response rates for the low-MA students in any phase of the edible or vibratory conditions. No significant difference in reinforcer effectiveness was observed across various phases for students in the high-MA groups.