Study On The Difference Of Attention Bias Between Overweight/Obese And Normal Individuals

Objective:With the improvement of people's living environment and the abundance of food resources,obesity has become a popular topic.It brings all kinds of physiological and psychological problems.There are many factors that lead to obesity,and the attention bias of food may be an important factor in obesity.In the environment of delicacy and food advertising,attention bias to food related clues may lead to individual food hunger and further unhealthy dietary behavior.There are differences in the results of the existing research paradigm because of the failure to accurately measure the three components of attention bias(facilitated attention,difficulty in disengagement and attentional avoidance),and the lack of control of the degree of starvation in the subjects.The related brain mechanisms are rarely studied and combined with the paradigm of measuring attention bias.In this study,an improved external clue paradigm was used to explore the behavioral differences between the three components of attention bias between overweight and obese people and those of normal weight,and to further analyze the components from the brain mechanism by using the functional Near Infrared Spectrum(fNIRS)technique.At the time of stimulation,200 ms and 500 ms were selected to measure three components and there were differences,and the attention bias of two groups of individuals to high and low energy food cues was observed.Methods:A total of 26 overweight and obese subjects(M=30.86,SD=5.86)and 25 normal weight subjects(M=20.46,SD=1.95)were involved in the experiment.The subjects were 18~30 years old(M=23.27,SD=2.51),including 27 women and 24 men.The formal experiment uses an improved external clue paradigm to measure the response of two groups of subjects respectively,and then calculates the attention orientation score and the attention disengagement score.If the score is less than 0,it shows that there is attention avoidance.Single sample T test was used to calculate the specific attentional bias of the two groups.In the task,the blood oxygen signals of 20 channelsin the prefrontal region of the subjects were collected by multichannel functional near-infrared spectroscopy.In the 200 ms and 500 ms stimuli,the time clue effective conditions(related to facilitated attention)and the ineffective conditions(related to attention disengagement)were calculated by repeated measurements of variance analysis.Type and grouping of oxygenated hemoglobin(Hbo).Results:The behavioral results showed that there was no significant difference between the attention orientation score and the attention disengagement score of the overweight and obesity group at the time of 200 ms stimulation,and the attention orientation score of the high energy food picture was more than 0 in the normal weight group and the score of attention disengagement was less than 0.At the time of500 ms stimulation,the scores of attention disengagement for low energy diet were significantly less than 0 in overweight and obese subjects,and there was no significant difference between the score of attention orientation and the score of attention disengagement and 0 in the normal weight group.FNIRS results showed that the main effects of channel 4 and channel 11 were significant under the time clues of 200 ms stimulation,and the high energy food picture was significantly higher than the low energy food picture and the neutral picture.The picture type×group interaction was significant,and the normal weight group was exposed to oxygen hemoglobin under the high energy food picture.The amount(Hbo)was significantly higher than that of low energy food picture and neutral picture.The main effect of the 8,9 and 10 passages in the channel 8,9 and 10 was significant,and the high energy food picture was significantly higher than the low energy food picture and the neutral picture.The picture type×group interaction was significant,and the content of oxygen hemoglobin(Hbo)in the overweight and obese subjects under the high energy food picture was significantly higher than that of the low level.Energy food picture and neutral picture.Under the condition of 500 ms stimulation presenting time clues,the interaction of channel 4 picture type and group was significant.Under the condition of high energy food picture cue,the content of oxygen hemoglobin(Hbo)in normal body weight group was significantly higher thanthat of overweight and obese subjects.The oxygen content of hemoglobin(Hbo)in normal weight group was significantly higher than that in low energy food picture and neutral picture.The main effect of the channel 5 picture type was significant under the condition of the time clue of 500 ms stimulation,and the content of oxygen hemoglobin(Hbo)in the high energy food picture was significantly higher than that of the neutral picture.The interaction between the picture type and the group was significant.The content of oxygen hemoglobin on the high energy food picture of the overweight and obese group(Hbo)significantly higher than the normal weight group,and overweight and obese subjects under high energy food picture conditions of oxygen hemoglobin content(Hbo)high and low energy food picture and neutral picture.ConclusionThere were differences in food attention bias between overweight obesity group and normal weight group.Behavioral studies showed that in normal weight group,attentional orientated acceleration of high-energy food was accelerated at the time of 200 ms stimulation,followed by accelerated attention withdrawal.In the overweight and obese group,the attentional detachment of the low energy food was accelerated at the time of 500 ms stimulation.At the hemodynamic level,200 ms stimulation presented time clues in the normal body weight group.The activation of oxygen in the orbital frontal cortex(Channel 4and channel 11)was significantly higher than the low energy food map and the neutral map in the normal body weight group.In the overweight and obese group,the oxygen activation of the dorsolateral prefrontal lobe(Channel 8,channel 9 and channel 10)was significantly higher in the overweight and obese group than in the neutral map.Under the time of 500 ms stimulation,the normal body weight group was significantly higher than the low energy food map and the neutral map in the orbital frontal cortex(Channel 4)of the high energy food map.The activation of oxygen in the dorsolateral prefrontal lobes(Channel 5)was higher in overweight and obese subjects than in low energy food pictures and neutral maps,and the blood oxygenactivation of the dorsolateral prefrontal lobes(DLPFC)in the overweight and obesity group was significantly greater than that in the normal body.In summary,high-fat food cues were detected more quickly in normal weight subjects when confronted with food cues.The higher activation of attention related brain regions may contribute to the earlier adoption of food control strategies.Normal weight people and overweight and obese people can quickly break away from food cues,but in the process,overweight people pay more cognitive efforts.