Habituation and within-session changes in motivated responding for food in children

Abstract

Within-session decreases in instrumental responding to obtain food, consistent with habituation, have been reliably demonstrated in adults and children. This study tested the hypothesis that within-session decreases in instrumental responding for food are due to habituation rather than satiation. Thirty-eight 8-12-year-old children performed a computer-based operant task to earn points toward access to potato chips for 20 min, and for chocolate candies for the final 6 min of the session. Portion size of the food reinforcer (75 kcal vs 225 kcal) and food consumption (consumption/no consumption). There was no difference in the rate of response decrease between the two portion size conditions. Both the consumption and non-consumption groups showed response decelerations during the first 20 min, with responses in the consumption group decreasing at a faster rate. When the novel food was presented, participants in all conditions recovered responding. Although satiation may contribute to reductions in motivated responding for food when food is consumed, habituation provides a more complete explanation for the results observed in this study.

Figure 1

Mean ± SEM number of responses for potato chips (habituation; trials 1–10) and M&M’s (recovery; trials 11–13) for individuals A. who consumed the food throughout the duration of the experiment (black circles) and those who had to delay consumption until the end (white circles) and B. participants assigned to small (75 kcal; black circles) and large (225 kcal; white circles) portions of food. The habituation phase is shown to the left of the dashed line and the recovery phase is to the right of the dashed line in both figures.