Improved Planning Abilities in Binge Eating

ObjectiveThe role of planning in binge eating episodes is unknown. We investigated the characteristics of planning associated with food cues in binging patients. We studied planning based on backward reasoning, reasoning that determines a sequence of actions back to front from the final outcome.MethodA cross-sectional study was conducted with 20 healthy participants, 20 bulimia nervosa (BN), 22 restrictive (ANR) and 23 binging anorexia nervosa (ANB), without any concomitant impulsive disorder. In neutral/relaxing, binge food and stressful conditions, backward reasoning was assessed with the Race game, promotion of delayed large rewards with an intertemporal discounting task, attention with the Simon task, and repeating a dominant behavior with the Go/No-go task.ResultsBN and to a lower extent ANB patients succeeded more at the Race game in food than in neutral condition. This difference discriminated binging from non-binging participants. Backward reasoning in the food condition was associated with lower approach behavior toward food in BN patients, and higher food avoidance in ANB patients. Enhanced backward reasoning in the food condition related to preferences for delayed large rewards in BN patients. In BN and ANB patients the enhanced success rate at the Race game in the food condition was associated with higher attention paid to binge food.ConclusionThese findings introduce a novel process underlying binges: planning based on backward reasoning is associated with binges. It likely aims to reduce craving for binge foods and extend binge refractory period in BN patients, and avoid binging in ANB patients. Shifts between these goals might explain shifts between eating disorder subtypes.【研究目的】目前尚不清楚计划在暴食发作（binge eating episode）中所扮演的角色。本研究旨在探究暴食患者中与食物线索相关的计划特征，并基于反向推理（backward reasoning）开展计划相关研究——该推理方式指从最终结果出发，倒推得出完整行动序列。【研究方法】本研究为横断面研究，共纳入20名健康对照参与者、20名神经性贪食症（bulimia nervosa, BN）患者、22名限制性神经性厌食症（anorexia nervosa restrictive, ANR）患者及23名暴食型神经性厌食症（anorexia nervosa binge-eating, ANB）患者，所有参与者均未伴随冲动障碍。在中性/放松、暴食相关食物及应激三种情境下，分别通过以下任务评估各项指标：采用赛车任务（Race game）评估反向推理能力，采用跨期折扣任务（intertemporal discounting task）评估个体对延迟大额奖赏的偏好，采用西蒙任务（Simon task）评估注意力水平，采用Go/No-go任务评估优势行为重复能力。【研究结果】神经性贪食症（BN）患者在食物相关情境下的赛车任务完成成功率显著高于中性情境，暴食型神经性厌食症（ANB）患者也存在该趋势但程度较弱。该特征差异可有效区分暴食组与非暴食组参与者。在食物相关情境中，反向推理能力与神经性贪食症（BN）患者的食物趋近行为呈负相关，与暴食型神经性厌食症（ANB）患者的食物回避行为呈正相关。神经性贪食症（BN）患者在食物相关情境下增强的反向推理能力，与其对延迟大额奖赏的偏好显著相关。此外，神经性贪食症（BN）与暴食型神经性厌食症（ANB）患者在食物相关情境下赛车任务成功率的提升，均与其对暴食相关食物的注意力增强呈正相关。【研究结论】本研究揭示了暴食发作背后的全新机制：基于反向推理的计划过程与暴食发作密切相关。该机制在神经性贪食症（BN）患者中或可降低其对暴食相关食物的渴求，并延长暴食发作后不应期；在暴食型神经性厌食症（ANB）患者中则可帮助其避免暴食发作。不同亚型进食障碍患者在该计划目标上的差异，或可解释进食障碍亚型之间的转化。