Acquisition, maintenance, and generalization of productive intraverbal behavior through transfer of stimulus control procedures.

The acquisition of productive intraverbal behavior involving the emission of thematically related responses was evaluated. Three mentally retarded children participated in this study and a multiple-probe design was used in training productive intraverbal behavior (three stimulus classes). Training was conducted using an errorless discrimination procedure (prompt delay) and a variation of this to transfer vocal responses from control of visual stimuli (tact behavior) to verbal stimuli (intraverbal behavior). Reinforcement probability was equal for correct responses prior to and following a prompt and incorrect responses were ignored. Acquisition criteria were reached when subjects emitted 80-100% correct responses and more than four different responses per session during three consecutive sessions. These criteria were achieved in all three subjects. Prompt delay procedure produced no incorrect responses, decreased acquisition criteria slightly over time, produced responses generalization during training, and increased comprehensive intraverbal behavior after training productive intraverbals. Variations in prompt delay procedure produced the same results except a low rate of errors and chaining of different responses per trial appeared when an additional prompt was implemented.