RESUMO
The main aim of the study was to assess the effects of varying response modality in the human allocation of operant responses to different reinforcement sources using a rapidly changing environment procedure. A total of nine undergraduate students participated. In each session, participants were presented with seven independent concurrent variable interval schedules of reinforcement in an irregular order. Individual schedules lasted for the delivery of five reinforcers. In Experiment 1, six students were randomly assigned to two conditions (BO and MT). In the BO condition, participants pressed buttons on the screen to earn points. In the MT condition, participants tracked and pressed moving targets that changed position every 2000 ms. Results showed that sensitivity to reinforcement developed just for the BO condition. A second Experiment was conducted, having three participants, and using the MT condition only. The rate of target position change parameter was modified to 300 milliseconds. Under those conditions, the development of sensitivity to reinforcement was observed. However, variable performances were found. It is concluded that response modality can affect the development of sensitivity if response requisites to obtain reinforcement depend on the way the response modality is arranged (AU)
