The effects of a variable ratio (VR) schedule of reinforcement on exercising in obese and non-obese children were examined. Eight 11-year-old boys, four obese and four non-obese, participated as subjects. One obese and one non-obese boy served as a control for social attention and maturation effects. Three obese and three non-obese boys were individually tested five times weekly over approximately 12 weeks on a stationary bicycle. A changing-criterion design was used where 3 VR phases of 8 sessions each were followed by a 3 session mini-reversal phase and a 5 session return-to-third VP phase. Each successive criterion was increased over previous performance by approximately 15%. Implementation of the initial VR subphase produced marked increases in the rate of exercising for all children with continued acceleration until the withdrawal of reinforcement phase when rates decreased. Response rates recovered during the final VP phase where the highest rates were achieved for all subjects. Cumulative records demonstrated high stable responding with no discernible pausing for non-obese boys. In contrast, pausing and accelerating which were initially evident in the obese boys' records were eliminated with higher VR schedules. The anthropometric measures taken at the pre-experimental, post-experimental and follow-up time periods revealed that the obese boys who participated in the program gained substantially less weight than children who did not participate. There appeared to be no systematic difference in self-reported food intake between obese and non-obese children. Actometer data, as well as parents' and teachers' written and verbal reports indicated that exercise on a stationary bicycle, intermittently reinforced, as well as training parents to utilize praise and attention for exercise, appeared to increase physical activity in the natural environment. A social validation questionnaire as well as informal observation revealed that participants, parents, and teachers rated the biking program most positively.
| Identifer | oai:union.ndltd.org:MANITOBA/oai:mspace.lib.umanitoba.ca:1993/23601 |
| Date | 27 May 2014 |
| Creators | De Luca, Rayleen V. |
| Contributors | Holborn, Steven (Psychology), Holborn, Steven (Psychology) LeBow, Mike (Psychology) Jehu, Derek (N/A) Johns, David (N/A) Brownell, Kelly (N/A) |
| Source Sets | University of Manitoba Canada |
| Detected Language | English |
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