The Neural Mechanism Of Psychogenic Eating

Eating behavior is the process by which people consume food for the purpose of maintaining their own energy needs.It is a basic biological instinct to ensure human survival,and it is important for maintaining normal physiological activities.The individual's daily eating behavior includes both the physiological eating behavior which is due to hunger trails and aims at making up for energy consumption,and the psychogenic eating behavior which is driven by hedonic and reward-driven in non-starvation states.These eating behavior affect the type and amount of food selected by the individual,and may cause excessive energy intake and obesity risk.The eating behavior triggered by psychological needs can be roughly divided into three types: restrained eating,uncontrolled eating,and emotional eating.Psychogenic eating behavior has attracted extensive attention from researchers at home and abroad,researchers have put forward many theoretical models such as Psychosomatic Theory,Theory of Externality,Boundary Model,A dual-systems perspective,Goal conflict model,to explain the reasons for the psychogenic eating behavior.Researchers have conducted a large number of cognitive neurological studies,trying to explore the deep neural mechanisms of psychogenic eating behavior.The results of the studies showed that psychogenic eating behavior is related to multiple brain functional activities such as reward assessment and inhibition control,and is affected by their own internal physiological balance mechanisms,hedonic mechanisms and control mechanisms.However,previous psychogenic eating behavior studies mostly focused on the neural mechanisms of restrained eating.There were few studies on the neural mechanisms of uncontrolled eating and emotional eating.Moreover,these studies mainly focus on the task-based brain activity of the individual during food cues processing,and less on the effects of individual psychogenic eating behavior on the brain structure and resting-state functional connectivity.Due to the plasticity of the brain's nervous system,its structure and resting-state functions are affected by the environment and behavior.Therefore,carrying out research on the corresponding brain structure and resting state function is an important direction to understand the neural mechanism of psychogenic eating behavior.This study used nuclear magnetic resonance technology to integrate brain structure and functional imaging data.From the perspective of individual differences,a voxel-based morphology research method explores the relationship between different psychogenic eating behaviors and the volume of gray matter in the brain,and explores the structural characteristics of the brain with restrained eating,uncontrolled eating,and emotional eating.On the basis of the differences in brain structure,from the perspective of functional integration,we explored the relationship between resting-state functional connections in brain regions and individual psychogenic eating behaviors.Study 1 evaluated the daily psychogenic eating behavior of individuals through a revised three-factor diet questionnaire with cross-cultural stability and high ecological validity.It used 3D brain structure data,selected Chinese young women in the normal weight range as subjects(N=158),used brain gray volume as a structural indicator,employed a multiple linear regression model to explored the relationship between the local gray matter volume and psychogenic eating behavior from the perspective of individual differences.The study found the following results: The restrained eating was positively correlated with the gray matter volume in right precuneus.The uncontrolled eating was positively correlated with gray matter volume in bilateral cerebellum,and negatively correlated with left anterior cingulate cortex,middle cingulate cortex,and supplementary motor area.The emotional eating was not found to be significantly correlated with the gray matter volume in the whole brain.Based on Study 1,study 2 used resting-state magnetic resonance data from the same group of subjects,adopted the brain regions with significant differences in brain structure(right anterior precuneus and left anterior cingulate cortex)as the ROI(regions of interest)and calculate the functional connectivity between the ROI and other voxels in the whole brain.Study 2 through multiple linear regression models further explored whether changes in brain structure with different psychogenic eating behaviors would affect the functional connectivity changes in their corresponding brain regions.The results showed that the resting-sate functional connectivity strength of the right precuneus and bilateral thalamus was negatively correlated with the restrained eating.And the resting-state functional connectivity between left anterior cingulate cortex and right insula and dorsolateral prefrontal cortex were negatively correlated with the uncontrolled eating.Taken together the above results,this study believes that high levels of restrained eating individuals exhibit increased gray matter volume in brain regions associated with attention and self-processing,which may be related to their excessive self-concern on their body shape,and the decreased functional connectivity between the precuneus and the individual sensory information center(bilateral thalamus)may hinder individuals' self-processing information integration,and thus affect their correct judgment of their own body type.Higher self-concern and wrong weight judgments make restrained eaters more inclined to adopt restrictive strategies for food intake in their daily eating behavior.In addition,according to the dual-systems perspective,the individual produces uncontrolled eating because the hedonic-driven impulse system occupies a dominant position,and the reflective system responsible for inhibiting control is unable to control the desire for appetite.The results of this study provide a possible neurological explanation for the dual-systems perspective.High levels of uncontrolled eating individuals may show increased gray matter volume in the brain regions associated with attention and low-level desire to eat(bilateral cerebellum),and reduced gray matter volume in the brain regions associated with inhibitory control(anterior cingulate cortex,middle cingulate cortex,and supplementary motor area).This may mean that high uncontrolled eating groups are more concerned about food stimuli,are more prone to produce hunger and eating cravings,and the suppression of inhibitory control ability makes it more difficult for them to suppress this desire to eat.At the same time,the decrease in functional connectivity between the anterior cingulate gyrus and the reward-related brain area(right insula)and region involved in inhibition(right dorsolateral prefrontal cortex)further pointed out that high levels of uncontrolled eating habits reduce the ability to monitor desire to eat and suppress control.This increased sensitivity to food rewards and reduced ability to control inhibition will allow individuals to rely more on perceiving impulse systems to make decisions when faced with an external environment that is full of food enticement,rather than reflecting on the consequences of processing behavior,leading to Individuals have excess energy intake.