The Effects Of Memory Retrieval Suppression On Food Reward Processing

Obesity has become a public health threat for almost all ages.The excessive reward responsiveness and deficit in inhibition to food-related stimuli are considered as the risky factors of obesity.Previous studies focused on the effect of motor inhibition on reward response and its relationship with obesity.Memory retrieval suppression attracts the researchers’attention to cognitive inhibition.Memory retrieval suppression refers to the process of destroying memory and realizing motivated forgetting by inhibiting information retrieval.It is usually studied by using the task of"think/no think(TNT).Memory retrieval suppression has the stability of cross stimulus types and test modes,and could destroy the neutral and negative emotional memory.Recently,some studies with drinking scenes or delicious food pictures have found that retrieval suppression is effective in the reward related content.While the retrieval suppression impacts the negative emotional memory and reduces the negative feelings,it is unknown whether the effects of the retrieval suppression on the food reward memory is stable,and whether it will change the reward processing of food.As shown in prior studies,food reward processing includes three levels:subjective reward value(liking and wanting),automatic perceptual processing(such as visual attention bias)and cognitive processing(such as decision-making reflecting impulse control).Therefore,this paper using two kind of materials,based on TNT task,explored(1)whether the retrieval suppression of food related memory has the effectiveness and stability of cross stimulus type;(2)whether the retrieval suppression impacts food reward processing.This paper hypothesized that(1)retrieval suppression would destroy recall of both food and non-food memory;(2)memory extraction inhibition could attenuate liking and wanting of food stimuli,attention bias caused by food stimuli,and the tendency to choose tasty but unhealthy food.Study 1 aimed to investigate the effects of memory retrieval suppression on the subjective reward value(liking and wanting)by using delicious food vocabulary as the target stimulus.Forty-three female college students aged 19.77±1.41 years old with the body mass index(BMI)of 22.39±3.10 kg/m~2 were involved in the study 1.The single factor within-subject experimental design was adopted,with memory condition(T/baseline/NT)as the within-subject variable.TNT task learning,TNT and test stages were conducted on the day of experiment,and then the liking and wanting were rated.The results showed that the recalled percentage after NT was significantly lower than that of baseline and T conditions,which indicated that the retrieval suppression of food-related memory was effective.The results also showed that compared with T condition,liking and wanting of food vocabulary after NT were significantly reduced.Correlation analysis showed that the suppression induced wanting decline was negatively correlated with BMI.Study 2 aimed to investigate the effect of memory retrieval suppression on attention bias by using delicious food pictures as target stimuli and non-food pictures as control.Thirty-four female college students aged 18.83±0.75 years old with BMI of 21.23±2.06 kg/m~2 were enrolled in the study 2.The experimental design was designed with 3(memory condition:T/baseline/NT)x 2(picture type:food/neutral).The experiment was divided into two sessions.On the first session,body components and trait questionnaire were collected.On the second session,the TNT task and dot-probe task were conducted.The results showed that the recalled percentage of food pictures was lower than that of neutral pictures,but no difference was found between different memory conditions.Similarly,for attention bias,the subjects could identify the probe after food pictures more accurately,but the retrieval suppression did not affect accuracy.For the reaction time,no main effect of memory condition and interaction between memory condition and picture type were observed.Study 3 aimed to investigate the stability of reward memory retrieval suppression and whether it acts on food decision-making by using tastiness-health-decision task.Also,the effect of memory retrieval suppression on the subjective reward value was tested again by comparing the pre-and post-test.Thirty-nine female college students(age:18.59±0.88 years old)with BMI of 20.92±1.75 kg/m~2 were enrolled in the study 3.The experiment included two sessions.On the first session,the body composition,the trait questionnaire and the pre-test of subjective reward value were collected.On the second session,the TNT task,decision-making task and subjective reward value task were completed.The overall design was designed with 3(memory condition:T/baseline/NT)x 2(picture type:food/neutral).The results showed that the recalled percentage of NT pictures was lower than that of T pictures regardless of the food pictures and non-food pictures.However,there is no difference between three memory conditions in the decision intensity as well as the weight of tastiness and health on decision intensity.For the subjective reward value,the wanting of NT condition was significantly lower than that of T condition in the post test.In the NT condition,wanting of food pictures decreased significantly in the post-test than in the pre-test.Correlation analysis showed that the decrease of desire caused by NT(pre vs.post)was negatively correlated with visceral fat.In conclusion,the above studies show that the effective retrieval suppression is also stable in the memory content related to food reward.The higher BMI and the higher the visceral fat,the more difficult to reduce the desire for food via memory retrieval suppression.