Saelens B E, Epstein L H
Department of Psychology, University at Buffalo, NY 14260, USA.
Appetite. 1996 Aug;27(1):41-50. doi: 10.1006/appe.1996.0032.
Food is a powerful reinforcer, and individual differences in the reinforcing efficacy of food may provide a mechanism to explain the excess intake and positive energy balance responsible for obesity. The present study tested the hypothesis that eating palatable food would be more reinforcing than engaging in sedentary activities (e.g. playing computer games) for obese in comparison to non-obese non-dietary restrained female college students. Subjects could choose to eat food or engage in sedentary activities based on their responding in a computer-generated concurrent schedules task. The reinforcement schedule associated with earning access to sedentary activities was held at variable ratio 2 (VR2) while the food reinforcement schedule was set at VR2 in the first trial of the choice task and doubled across the four subsequent trials from VR4 to VR32. Choice and consumption results indicated that eating was significantly more reinforcing than engaging in sedentary activities for obese subjects than non-obese subjects. Hedonics for the activities and foods were not correlated with total food reinforcers earned and did not differ between the groups. These results confirm the hypothesis that eating food is more reinforcing than selected alternative activities to a greater extent for obese than for non-obese young women.
食物是一种强大的强化物，食物强化功效的个体差异可能提供一种机制，用以解释导致肥胖的过量摄入和正能量平衡。本研究检验了这样一个假设：与非肥胖且无饮食限制的女大学生相比，食用美味食物对肥胖者而言比从事久坐活动（如玩电脑游戏）更具强化作用。在计算机生成的并发日程任务中，受试者可根据自身反应选择进食或从事久坐活动。与获得久坐活动机会相关的强化程序设定为可变比率2（VR2），而食物强化程序在选择任务的首次试验中设定为VR2，并在随后的四次试验中从VR4翻倍至VR32。选择和消费结果表明，与非肥胖受试者相比，进食对肥胖受试者而言比从事久坐活动更具强化作用。对这些活动和食物的享乐反应与获得的食物强化物总量无关，且两组之间无差异。这些结果证实了这一假设：与非肥胖年轻女性相比，进食对肥胖年轻女性而言在更大程度上比选定的其他活动更具强化作用。
