食物线索注意偏向及其神经机制

与其他类型的刺激相比, 个体会优先注意食物相关刺激, 即对食物刺激的注意偏向。对影响食物线索注意偏向个体因素研究的分析发现：(1)在状态因素中, 饥饿以及与自我威胁有关的、唤起强度大的负性情绪对食物线索注意偏向有增强作用, 这在注意加工的早期和晚期都有体现; (2)在特质因素中, 行为研究发现, 相比于体重正常个体和非限制性饮食者, 超重/肥胖个体以及唤起节食目标的成功限制性饮食者没有更强的注意偏向, 但是, ERP研究发现, 在注意加工的早期阶段, 就出现了特质因素对食物线索注意偏向的影响; (3) fMRI研究发现, 对食物线索的注意过程伴随着脑岛、眶额叶皮层等与奖励相关的脑区及视觉注意网络的激活。未来研究需要：(1)从动态角度研究注意偏向, 进一步提高测量的信度; (2)使用专门的范式探究个体因素影响注意偏向的神经机制; (3)严格分离不同状态因素; (4)对被试进行严谨筛选和划分, 做好被试间的对比研究。     

中国人限制性饮食和食物渴求的认知神经机制

物质丰富的时代, 如何抵御美味食物线索带来的食物渴求, 并限制饮食从而保持健康成为人们关注的重要话题之一。近年来, 国内学者为了探讨节食成功的原因, 创建中国食物图片库, 考察限制性饮食的认知神经机制, 以及成功和失败限制性饮食者的脑机制差异; 开展了特质食物渴求及中国特色的辣食渴求的认知神经研究。对推进饮食行为研究的理论发展, 也为肥胖、饮食失调等健康干预工作提供重要支持。     

限制性饮食者对食物线索的注意偏向：基于目标矛盾理论模型

采用点探测变式探讨了120名成功和失败女性限制性饮食者对两类食物线索的注意偏向机制。结果发现, 当只启动享乐目标时, 成功的限制者存在对美味食物线索的注意回避, 失败的限制者存在对美味食物线索的注意脱离困难; 当相继启动享乐目标和节食目标时, 成功和失败两类限制者均存在对美味食物线索的注意回避, 但失败者仍然存在注意脱离困难。从目标矛盾模型理论对实验结果进行了讨论。     

中国人身体自我及饮食行为研究:十年回顾

最近十年,国内学者对中国人身体自我和饮食行为进行了理论和实证上的本土化探索,主要涉及对中国化身体自我和饮食行为测量工具的研制,身体自我的结构和特点;提出了"负面身体自我图式"概念和"负面身体图式指导负面身体自我者的认知加工"的重要观点,对该认知加工机制进行了一系列实验研究;探讨了负面身体自我形成的影响因素、预测模型;探讨了限制性饮食者的认知加工偏好、饮食失调人群的特点和学生超重的干预模式;初步探讨了负面身体自我注意偏好、限制性饮食者及饮食失调亚群对食物线索加工的脑机制。     

成功与失败限制性饮食者对食物加工的能量效应：注意偏向的眼动追踪

本研究通过眼动追踪考察两类限制性饮食者对食物注意偏向的成分。在高低能量食物分别和非食物配对时,成功者对高能量存在注意警觉（加速探测）-回避（早期和总体的回避）模式;失败者对高能量存在注意回避（早期定向回避）-维持（早期维持）模式,即在早期注意更少的定向于高能量,但一旦注意到就出现维持偏向。在高低能量配对时,成功者对高能量注意警觉（早期定向）-维持（早期维持）;失败者对高能量注意警觉（早期定向）-维持（早期、总体的维持) 。总体上,我们发现了不同亚类限制性饮食者对食物线索加工的能量效应,即失败者比成功者对高能量食物注意更多的眼动证据。     

成功与失败限制性饮食者对食物信息加工的能量效应:注意偏向的眼动研究

本研究通过眼动追踪考察两类限制性饮食者对食物注意偏向的成分。在高低能量食物分别和非食物配对时,成功者对高能量存在注意警觉(加速探测)-回避(早期和总体的回避)模式;失败者对高能量存在注意回避(早期定向回避)-维持(早期维持)模式,即在早期注意更少的定向于高能量,但一旦注意到就出现维持偏向。在高低能量配对时,成功者对高能量注意警觉(早期定向)-维持(早期维持);失败者对高能量注意警觉(早期定向)-维持(早期、总体的维持)。总体上,我们发现了不同亚类限制性饮食者对食物线索加工的能量效应,即失败者比成功者对高能量食物注意更多的眼动证据。     

特质自我控制对食物线索注意偏向的影响及干预：来自眼动的证据

采用眼动技术,以BMI指数处于正常范围的女性为被试,考察特质自我控制对食物线索注意偏向的影响以及注意偏向训练在改变注意偏向强度上的干预效果。结果发现,对于高热量食物线索,低特质自我控制水平女性表现出了更强的注意偏向;注意偏向训练有效降低了低特质自我控制水平女性对高热量食物线索注意偏向的强度。上述结果表明,特质自我控制影响个体对食物线索的注意偏向,注意偏向训练能有效改变个体对食物线索注意偏向的强度。     

为何越减越肥?——限制性饮食者过度进食的心理机制及影响因素

限制性饮食作为一种被越来越多的女性所采用的减肥策略, 并不是一个有效的维持和降低体重的方法, 在许多情况下, 限制性饮食者反而比非限制性饮食者更容易发生过度进食, 本文回顾了国内外关于限制性饮食者过度进食的研究, 总结了限制性饮食者过度进食的心理机制以及预加载、情绪唤醒、自我损耗、认知资源分散、人格与社会五大影响因素, 并对现有的不足进行了探讨和对今后的研究提出了展望。     

不同动机网络使用者对网络使用线索的注意偏向

以29名信息获取性动机者和21名人际情感性动机者为被试,采用情绪Stroop范式,以网络信息获取线索、网络情感满足线索、一般负性情绪线索和中性线索为刺激材料,考察了不同网络使用动机者对网络相关线索和负性情绪线索的注意加工特性。结果发现,基于信息获取性动机的网络使用者对网络信息获取线索具有显著的注意偏向,而基于人际情感性动机的网络使用者对网络情感满足线索或负性情绪线索具有显著的注意偏向。该研究为解释网络相关线索和负性情绪线索诱发不同动机者上网欲望的认知机制提供了实验证据。     

在线抑制控制训练对失败的限制性饮食者不健康食物选择的改善

失败的限制性饮食者是进食障碍的高危人群,他们面对食物时的抑制控制能力通常很弱,从而更易发展为肥胖,所以改善失败的限制性饮食者对不健康食物的进食选择十分重要。本文采用在线停止信号任务,通过提高失败的限制性饮食者对不健康食物图片的抑制控制能力,从而减少他们在日常生活中对不健康食物的选择。首先对66名失败的限制性饮食者实施前测,然后随机分为对不健康食物图片进行抑制反应的干预组(n=33)和对非食物图片进行抑制反应的控制组(n=31),两组被试接受每天一次(每次10 min左右)共计7次的训练。完成训练后,所有被试均接受后测。结果发现,干预训练后,与控制组相比,干预组被试对不健康食物的选择频率以及对不健康食物自我报告的吸引力和喜爱程度均显著降低。     

The allure of forbidden food: On the role of attention in self-regulation

The aim of the present studies was to examine the impact of food cues on restrained eaters’ attention for food. Previous research has shown that restrained eaters spontaneously activate hedonic thoughts in response to palatable food cues, and that such food cues also lead them to inhibit their dieting goal. We argue that as a consequence, restrained eaters’ selective attention will automatically be drawn towards hedonically relevant food items. Consistent with our expectations, the results of two studies revealed that restrained eaters, but not unrestrained eaters, displayed an attentional bias for hedonically rated food items when they had been pre-exposed to food cues. However, this attentional bias did not occur when restrained eaters were primed with the concept of dieting, thereby rendering the regulation of eating behavior more successful. These findings are discussed in the context of implicit processes in self-regulation.     

Why dieters fail: Testing the goal conflict model of eating

A new theory of eating regulation is presented to account for the over-responsiveness of restrained eaters to external food-relevant cues. According to this theory, the food intake of restrained eaters is characterized by a conflict between two chronically accessible incentives or goals: eating enjoyment and weight control. Their difficulty in weight control is due to their behavioral sensitivity to eating enjoyment and its incompatibility with the eating control goal. Accordingly, exposure to food-relevant stimuli primes the goal of eating enjoyment in restrained (but not unrestrained) eaters, resulting in an inhibition of weight control thoughts. Three studies are reported that support these assumptions. Study 1 demonstrates a substantial relation between Eating Restraint and measures of ambivalence towards eating. Studies 2 and 3 show that priming eating enjoyment decreases the accessibility of eating control concepts. The results are discussed in the context of current research on the psychology of obesity and restrained eating.     

Healthy cognition: processes of self-regulatory success in restrained eating

Two studies examined self-regulatory success in dieting. Previous research has indicated that restrained eaters (i.e., chronic dieters) might fail in their attempts at weight control because the perception of attractive food cues triggers hedonic thoughts about food and inhibits their dieting goal. However, recent work suggests that in some dieters, temptation cues activate the relevant goal and thus facilitate self-regulation. The present work extends these findings by showing that self-regulatory success moderates the effect of food cues on restrained eaters such that food cues activate the dieting goal in successful restrained eaters and inhibit the dieting goal in unsuccessful restrained eaters. The specific time course of these effects was examined. Moreover, a correlational study revealed that only successful restrained eaters translate their dieting intentions into action. Results are discussed in the context of nonconscious self-regulation and the role of automatic processes in the link between intention and behavior.     

Don't mind if I do: disinhibited eating under cognitive load

Past research has shown that strong emotional or motivational states can cause normally restrained eaters to overeat. In this article it is argued that simple cognitive load can also disinhibit eating by restrained eaters. Two studies examined this disinhibition effect. In Study 1, restrained and unrestrained eaters were given the opportunity to consume high-calorie food while performing either a high cognitive-load or low cognitive-load task. Restrained eaters consumed more food when under high cognitive load than when under low cognitive load; unrestrained eaters showed the opposite pattern. Study 2 replicated the disinhibition effect and ruled out stress, diminished awareness of food consumption, and ironic rebound as probable mediators. Results suggest that cognitive load may disinhibit consumption by preventing restrained eaters from monitoring the dietary consequences of their eating behavior. Implications for theories of self-regulation are discussed.     

Susceptibility for thin ideal media and eating styles

This study examined the relations between susceptibility for thin ideal media and restrained, emotional and external eating, directly and indirectly through body dissatisfaction. Thin ideal media susceptibility, body dissatisfaction and eating styles were measured in a sample of 163 female students. Structural equation modelling was used for analyses, controlling for BMI. Higher susceptibility for thin ideal media was directly related to higher scores on all eating styles, and indirectly related to higher restrained and emotional eating through elevated levels of body dissatisfaction. So, thin ideal media susceptibility was not only related to restraint through body dissatisfaction, but also directly. Emotional eaters might be more vulnerable for negative affect, whereas external eaters might be more sensitive to external cues in general.     

Differential effects of approach bias and eating style on unhealthy food consumption in overweight and normal weight women

Objective: The current study aimed to examine the effects of approach bias for unhealthy food and trait eating style on consumption of unhealthy food in overweight and normal weight individuals.

Method: Participants were 245 undergraduate women aged 17 – 26 years. They completed an Approach–Avoidance Task, the Dutch Eating Behaviour Questionnaire (to assess restrained, emotional, and external eating), and a taste test to measure consumption of unhealthy food.

Results: An external eating style predicted increased consumption of unhealthy food. Among overweight participants, external and emotional eating style individually moderated the relationship between approach bias for unhealthy food and subsequent consumption. Specifically, approach bias was positively related to consumption in high external and emotional eaters, but negatively related to consumption in low emotional eaters. These interactions were not observed among normal weight participants.

Conclusion: Practically, the results suggest that overweight individuals who are external or emotional eaters may benefit from interventions that aim to modify approach bias towards unhealthy food cues to reduce problematic eating behaviour.     

Biased perception of overeating in bulimia nervosa and compulsive binge eaters

This study investigated the relationship between caloric intake and perceived overeating in subjects with and without a history of problematic binge eating. Eighty subjects (20 in four groups: bulimia nervosa, compulsive binge eaters, obese, and normal controls) self-monitored eating for 2 weeks. The regression slopes for self-reported overeating as a function of caloric intake were contrasted across the four groups. At higher caloric levels, bulimics and binge eaters reported overeating at a significantly higher rate compared to obese and normal control groups. These data were interpreted as a type of cognitive bias whereby subjects with a history of binge eating distorted their perception of overeating at progressively higher caloric levels. It was proposed that excessive concern about eating and dieting may cause such cognitive biases. A parallel was drawn with body image distortion, which appears to be associated with overconcem with body size and shape.