The Mechanism Of Attention Bias For Food Cues Among Restrained Eaters

In recent years, as the borderline of eating disorder, restrained eaters have become the hot point research in psychology. Restrained eaters are chronic diets those who pay close attention to weight、figure and food, the characters of them are continuity、strong motivation, most of them are women, they want to lose weight or control their shape but always end with unsuccessful. They constantly force themselves ignore organism hunger to reduce food intake, that make them insensitive of organism hungry born ability, yet more sensitive of exogenous food cues and easier trigger them to overeat. Although overweight is one of the results of restrictive, the normal weight individual is also maybe the restrained eater.Most of previous studies were review the difference of restrained eaters and unrestrained eaters, the early stage research found there was no difference between them, but a lager number of following studies found out that there attention for food cues were different. From the literatures, we think out there will be two reasons for the inconsistencies.One of the reasons is research task. As the beginning, studies assessing attentional processing of food cues most commonly used an emotional Stroop-task. Yet, the Stroop-task has been subjected to criticism. Results appear highly dependent on the nature and presentation format of stimuli, with more consistent findings for blocked presentations. Because food and shape concerns represent different aspects of eating pathology, their simultaneous administration also makes it hard to draw firm conclusions about specific biases. The dot-probe task can study the components of attentional bias, such as attentional vigilance、attentional avoidance、attentional attainment and difficult to away attention from threat stimulates. The present study aimed to use the odd-one-out visual search task to disentangle the mechanisms of speeded detection and slowed disengagement in the attentional processing of food cues in restrained eaters. The exogenous cueing task (ECT), which allows differentiation between two components of visual attention:(1) attentional disengagement from a previously attended stimulus and (2) attentional engagement with a new stimulus. The paradigm consists of a computerized trial-by-trial cueing procedure. Specifically, we compared restrained and visual search and dot-probe paradigms provide only a discrete snapshot of responses after the onset of stimuli and fail to elucidate how attention is deployed prior to behavioral responses. While varying stimulus presentation times has been used to address the time course of attention, studies have pointed out this strategy still limits the assessment to discrete points during stimulus presentation. Because saccades or eye movements are guided by attention, eye-tracking technology is a non-invasive tool that provides a comparatively direct, continuous measure of visual spatial attention processing. While individual eye-movement studies have used one or more of these attentional indices, to date no research has assessed all of them.Another reason for the inconsistencies is participants. Most of the studies use Restraint Scale (RS) and the Dutch Eating Behaviour Questionnaire (DEBQ) to choose the subject of the restrained eaters. But in different research there were different score standard, which make its difficult to get out a consistency comparison. Resent search found out that, there were two parts of the restrained eaters, one was success to control their weight and keep their shape in a satisfactory condition; the other was fail to lose their weight and relapse diet and overeat. The success are considered to be the inhibited eaters, the failure are considered be to the disinhibited eaters. They are the person who gets the high scores in RS, also, the DEBQ can distinct them, with both high scores in DEBQ-R sub-scale and DEBQ-D sub-scale is disinhibited eater, with high scores in DEBQ-R sub-scale but low scores in DEBQ-D sub-scale is inhibited eater. Hence, in future designs, research on attentional processing of food cues has to acknowledge the impact of participants’restraint attitudes as well as their disinhibition tendencies.Thereupon, in this study, using the exogenous cueing task (ECT) to compare with the previous study for find out the definite attentional bias in early stage for short time-course. Using the eye-movement technology within the visual search paradigm to investigate the exact comparatively direct、continuous measure of visual spatial attention processing.In behavioral research, we used a modified ECT to explore the potential role of attentional engagement and attentional disengagement in the context of inhibited and disinhibited eaters in stimulus presentation duration of 200 ms and of 500 ms. In the meantime, assessed the high-caloric food and low-caloric food in four dimensions to compare with attentional mechanism, in order to make sure whether their cognitive process is in accord with behavioral response. The sample were all females included 61 inhibited eaters、64 disinhibited eaters and 68 unrestrained eaters drawn from undergraduate classes at Southwest University (SWU) in Chongqing, China. The2(time course: 200ms,500ms)×3 (group:inhibited eaters, disinhibited eaters or unrestrained eaters) X 2(cue validity:invalid or valid)×3(cue type:high-caloric food, low-fat food or neutral pictures) mixed design, with the undergraduate qualifications were between-subject variables, the postgraduate qualifications were within-subject variables. The ANOVA showed the main results can be summarized as follows:inhibited eaters and disinhibited eaters had different attentional bias in food cues. The disinhibited eaters showed initially a difficult to away attention from high-caloric food in 200 ms, subsequently attentioal avoidance in 500 ms; just showed a tendency of difficulty to away attention from low-caloric food in 200ms, no attentional bias in 500 ms; and in food assess task, they tended to choose more high-caloric food. The inhibited eaters showed initially a difficult to away attention from high-caloric food in 200 ms, no attentional bias in 500 ms; showed initially a difficult to away attention from low-caloric food in 200 ms, subsequently attentioal avoidance in 500 ms; and in food assess task, they tended to choose more low-caloric food. So it could deduct that the caloric of the food intake is the key point of whether succeed or not.In eye-movement study, within the visual search paradigm to address the time course of attention in the context of inhibited and disinhibited eaters in stimulus presentation duration of 2000 ms. The sample were all females included 32 inhibited eaters、37 disinhibited eaters and 40 unrestrained eaters drawn from undergraduate classes at Southwest University (SWU) in Chongqing, China. The3 (group:inhibited eaters, disinhibited eaters or unrestrained eaters) X3(picture pair: high-caloric food—neutral picture pair, low-caloric food—neutral picture pair or neutral—neutral picture pair) mixed design, with the first was between-subject variable, the second was within-subject variable, the dependence variables were four eye-movement indexes:direction bias, first fixation latency bias, first fixation duration bias and gaze duration bias. From the direction and latency of the initial shift in gaze to stimulus choices, biases in detection and orienting speed can be assessed from the first fixation latency, the interval between the onset of the stimulus pair and the onset of the first valid fixation on one stimulus. Maintenance biases have been operationalized as either the difference in average gaze durations of experimental versus control stimuli or differences in the first fixation durations on experimental versus control stimuli that are terminated by the participant rather than stimulus offset. The ANOVA showed the main results can be summarized as follows:inhibited eaters showed biases in initial orienting and overall maintainment, characterized by faster first fixations and overall mainrainment on low-caloric food compared to neutral pictures; characterized by faster first fixations, although no attentional avoidance, its overall maintainment was less then low-caloric food. Disinhibited eaters showed biases in initial orienting in speeded detection and overall maintainment, characterized by slower first fixations, initial maintainment and overall maintainment compare to neural pictures on both high and low caloric food, although no attentional avoidance on low-caloric food, its overall maintainment was significant less then high-caloric food.In a word, the results of eye-movement study were partial proved the results of behavioral study, and the exogenous cueing task was a valid paradigm to research attentioal bias in the relatively short stimulus presentation. It’s useful to know the mechanism of cognize process of restrained eaters, and provided theoretic guidance to prevent and interrupt overweight.