On the displacement of leisure items by food during multiple-stimulus preference assessments.

Previous studies have demonstrated that when food and leisure stimuli are combined in multiple-stimulus preference assessments, individuals typically select food more often, although the leisure stimuli also have known reinforcing properties. The purpose of the current study was to replicate this effect and determine its durability by examining the effect after mealtimes. Four adults who had been diagnosed with severe mental retardation were given three initial multiple-stimulus (without replacement) preference assessments (i.e., food, leisure stimuli, and combined). All participants selected food items as the most preferred stimuli in the combined assessments. Combined assessments were then administered immediately before and after the evening meal for each participant for 1 week. The results showed similar data both before and after mealtimes.