External beam radiation therapy is often used as a form of treatment for individuals diagnosed with cancer. However, because staying completely still can often be difficult for children, sedation is often used daily to remedy the need for stillness. In this document, we introduce the development, implementation, and testing of a technology designed to teach healthy children to self-monitor and control their movements. This technology monitored a child's body movement and created a continuous feedback loop, playing a preferred movie based on the amount of body movement observed. Study 1 compares the amount of body movement observed when children were instructed to remain still (instructions alone) to access to a movie contingent on maintained low rates of movement (contingent movie). Study 2 compares the amount of body movement observed in the instructions alone condition with two other conditions: non-contingent access to a movie (non-contingent movie) and contingent movie. Study 3 compares the amount of body movement observed in the instructions alone condition to the contingent movie condition over an extended period of time. Lastly, Study 4 compares the amount of body movement observed when children have previously been taught to stay still using the technology described above across various days throughout various conditions. Generally, we found three things: a) instructions alone were insufficient to produce the level of control over motion required; b) some control over motion was established in the non-contingent movie condition relative to the instructions alone condition; and c) the combination of movies and feedback contingent on movement was necessary to gain the level of control over body motion necessary to adhere to the medical protocol.