【作者】 孔繁昌；

【导师】 陈红；

【作者基本信息】 西南大学 ， 基础心理学， 2012， 博士

【摘要】 进食是生存和日常生活必不可少的重要组成部分。食物诱惑无时不在,如何在充满诱惑的生活环境中,成功地控制体重是一个具有现实意义的重要课题。限制性饮食就是以控制体重为目的,长期严格地控制进食的倾向。大量研究一致表明限制性饮食能够预测暴饮暴食、超重和肥胖的发展,是饮食失调发展过程中这一适应不良心理到不良行为转变的关键点。同时,我国的饮食失调、肥胖人数虽不及西方发达国家,但增长迅猛,发展提前,饮食相关的问题已经严重威胁到国民的身心健康并诱发一系列社会问题。因此对限制性饮食的系统研究不仅有助于揭开饮食失调等饮食问题的根源,丰富和拓展饮食的相关理论,也有助于推动更具针对性和实效性的预防和干预活动的开展。以往对限制性饮食的研究以行为研究居多,认知神经机制研究还不多见,研究结果多样化,还未能达成一致。因此,对限制性饮食的系统研究将具有重大的理论意义、实践意义和现实意义。基于“为什么一些限制性饮食者能够节食成功而一些限制性饮食者则不能”这一节食领域的基本问题,本研究首次采用ERP技术和fMRI技术系统地考察了限制性饮食者对食物线索的注意加工偏好及其脑区激活特征,共包括3个行为研究,4个ERP研究和1个fMRI研究。首先,行为研究方面,验证了限制性饮食量表在中国女大学生群体中的适用性(研究1、2),建立了标准化的中国食物图片库(研究3)。其次,ERP研究方面,采用视觉点探测任务,从阈上和阈下分别考察了限制性饮食者对食物索的注意偏向(研究4、5)；采用GO/NOGO范式和双任务Oddball范式分别考察了限制性饮食者的一般抑制能力和特定抑制能力(研究6、7)。最后,fMRI研究方面,采用经典的视觉食物图片线索任务,考察了限制性饮食者对食物线索加工的脑区激活特征(研究8)。本研究得出以下主要结论：(1)中文版的限制性饮食量表(限制性量表和荷兰饮食行为问卷等)具有稳定的因素结构,良好的信度和效度,可以作为对饮食行为测量的有效工具。(2)本研究创建了标准化的中国食物图片库,并建立了年轻女性群体在食物重要维度(如美味度)的参数。该库符合中国人日常饮食的基本结构,具有较高的可靠性,可以为食物相关领域的研究提供重要材料基础。(3)本研究重新界定了成功限制性饮食者和失败限制性饮食者,并对两类群体进行了操作化定义。成功限制性饮食者是长期对进食行为进行控制,具有高饮食限制低饮食解脱的特征,身体指数正常,且维持该体重指数至少在6个月以上的慢性节食者。失败限制性饮食者是长期对进食行为进行控制,具有高限制高解脱的特征,进行体重控制至少6个月以上的慢性节食者。这为限制性饮食的深入研究奠定了基础。(4)成功限制性饮食者和失败限制性饮食者对食物线索均存在注意偏向,但在注意偏向的具体成分上存在显著差异。成功限制性饮食者主要表现为对食物线索的注意警觉和注意回避,而失败限制性饮食者主要表现为对食物线索的注意警觉、注意回避和注意脱离困难。(5)限制性饮食者对食物线索的注意偏向可能与抑制能力受损有关。失败限制性饮食者而不是成功限制性饮食者存在一般抑制能力受损。成功限制性饮食者对高能量食物线索存在特定抑制能力受损,而失败限制性饮食者对高能量和低能量食物线索都存在特定抑制能力受损。(6)成功限制性饮食者和失败限制性饮食者对食物线索的加工具有不同的脑区激活模式。相对于正常饮食者,两类限制性饮食者对食物线索的加工都激活了奖赏和注意加工脑区,但成功限制性饮食者也激活了与执行功能和监控功能有关的脑区。(7)成功限制性饮食者和失败限制性饮食者对食物线索的注意加工具有不同的调节机制。成功限制性饮食者更多采用Coo1机制,即成功限制性饮食者比失败限制性饮食者对食物线索的加工更多地激活了与抑制相关的脑区。失败限制性饮食者多采用Hot机制,即失败限制性饮食者相对于成功限制性饮食者对食物线索的加工更多地激活了与奖赏相关的脑区。(8)本研究建构了限制性饮食者对食物线索注意加工的模型。两类限制性饮食者在对食物线索注意加工的动态时程和脑区激活的空间分布上都存在显著差异。总之,本研究表明成功的限制性饮食者和失败的限制性饮食者不仅具有不同的行为反应模式,也具有不同神经机制。这表明限制性饮食在改变人们的饮食行为的同时,也改变了大脑对食物线索的加工模式和神经基础。因此本研究不仅具有重大的理论意义也具有重要的应用价值。更多还原

【Abstract】 Eating is essential to our survival and daily life, and it’s well-known that food temptation is available easily. Therefore, how to successfully control one’s weight in an environment that is full of food temptation is an important issue with practical significance. Restricted eating refers to consistent, cognitively-mediated efforts to restrict eating for the purpose of weight control. Numerous studies has shown consistently that restrained eating can predict the development of Bing eating, overweight and obesity, and is also the key factor to the transmission from abnormal mental to abnormal behaviors in the development of eating disorders. On the other hand, the prevalence of eating disorders/obesity in China has been increasing rapidly and emerged ahead, although the number of eating disorders/obesity was limited and less than that of the counterparts in western developed countries. The arising problems with eating behaviors has been imposed higher risk on public physical and mental health, and also evoked a series of social problems. Therefore, systematically research on restrained eating will be benefit to explore the origin of eating disorder and other related problems with eating behaviors, enrich and expand theories of eating behavior and also promote more effectively and specially preventions and treatment. Prior findings focused on behavioral level of restrained eating, and studies to investigate the neural correlates of restrained eating were less. Meanwhile, the available findings were inconsistent and mixed. However, it is very important in theory, practice and application aspects to carry out systematic investigations of restrained eating in Chinese background.Our research aimed to examine the basic question in the filed of dieting why some restrained eaters can successfully control their weight and others can’t, and systematically explored the neural correlates of attentional bias among successful and unsuccessful restrained eaters with ERP and fMRI technologies. Our research comprised three behavioral studies, four Event-Related Potentials (ERPs) studies and an fMRI study. At the First, behavioral studies tested the reliability of restrained eating scales among Chinese female undergraduates (study1,2), and developed a standardized Chinese food picture system (study3). At the Second, in ERP studies,(masked) visual Dot-Probe paradigm was used to investigate the attentional bias on food cues in sub marginal and marginal levels (study4,5). Go/NOGO task and Two-task Oddball paradigm were also employed to investigate the general inhibition and specific inhibition among restrained eaters (study6,7). At the last, in an fMRI study, Food Cue Task was used to investigate the brain activation of food cues processing between successful and unsuccessful restrained eaters (study8). The main concludes were as follows.(1) The revised restrained scales, which included Restraint Scale and Dutch Eating Behavior Questionnaire, were stable in factor structure, excellent in reliability and validity, and can be used as a useful tool in evaluating eating behaviors.(2) This study developed a standardized Chinese food picture system that covered basic structures of Chinese diet, and also established the important indexes of food attributes among Chinese female undergraduates. The food system had sound reliability, can provide important basis for follow-up study.(3) Our research redefined successful restrained dieters and unsuccessful restrained eaters in a more scientific way, and also provided the conceptualized definition. Successful restrained eaters control their eating behavior consistently and strictly, and were characterized by higher restrained and lower disinhibitied level, with normal weight, and had maintained their current weight stable for at least6month. Unsuccessful restrained eaters control their eating behavior consistently and strictly, and were characterized by higher restrained and higher disinhibited level, and had weight loss for at least6month. These definitions would be benefit to more subsequent research.(4) These results showed that both successful restrained eaters and unsuccessful restrained eaters showed attentional bias toward food cues, but each demonstrated significantly different components. The components of attentional bias for successful restrained eaters were attention alluring and attention avoiding. And components of attentional bias for unsuccessful restrained eaters were attention alluring, attention avoiding, attention disengaging difficult.(5) The attention bias to food cues for restrained eaters was related to inhibition deficit. Unsuccessful restrained eaters not the successful restrained eaters showed deficit in general inhibition. On the other hand, successful restrained eaters were deficit in inhibition to high-energy food cues, and unsuccessful restrained eaters were sufficient in inhibition to both high-energy and low-energy food cues. (6) Both Successful and unsuccessful restrained eaters showed different brain activations in processing food cues. Relative to normal eaters, both restrained eaters showed stronger activations in brain cortexes related to reward and attention process, and successful restrained eaters also showed stronger activations in brain cortexes related to executive and monitoring function.(7) There are different moderating mechanisms in attentional process of food cues for successful restrained eaters and unsuccessful restrained eaters. Relative to unsuccessful restrained eaters, successful restrained eaters showed stronger activation in the cortex of inhibition processing, such as Frontal; Relative to successful restrained eaters, unsuccessful restrained eaters showed greater activations in the cortex of reward processing, such as middle OFC. However, unsuccessful restrained eaters often used "Hot" mechanism to moderate the attention process of food cues, and successful restrained eaters often used "Cool mechanism" to moderate the attention process of food cues.(8) This study developed an attention processing model of food cues among successful restrained eaters and unsuccessful restrained eaters. The successful restrained eaters processed food cues differently from unsuccessful restrained eaters not only in the temporal process, but also in the brain activations.In conclusion, the research demonstrated that successful restrained eaters and unsuccessful restrained eaters showed different behavioral response mode as well as different neural mechanism. This indicated that restrained eating changed the eating behavior, and also changed the mode of cognitive process and brain activations Therefore, this study is important not only in theory contribution, but also in application value.更多还原