Approach-Motivated Positive Affect Is Associated With Diminished Executive Function-related Prefrontal Cortex Activation In Obese Young Adults

Execution function as an advanced cognitive function plays an important role in regulating goal-orientation behaviour,and there is a distinction between the "cold" execution function and the "hot" execution function to distinguish the emotional involvement of different scenes.It have been suggested that obese individual revealed a significant flaw in cognitive function,including executive function.but the reason for this defect is still largely unknown.Based on the motivational dimensional model of affect theory in the field of positive emotions,cognitive deficits in obese people are likely to be caused by high approach-motivated positive affect.At present,the effects of high approach-motivated positive affect the executive function of obese people are largely unknown,especially on brain mechanism.Therefore,present study adapts the emerging neuroimaging techniquefunction near-infrared spectroscopy(fNIRS),to explore the difference in brain activation induced by the motivational dimensional,and to explore the relationship between positive emotions and executive function on obese people.Three studies examined the executive function consequences of approach-motivated positive-affect states:74 obese subjects participated in the first experiment,this study asked the subjects to a food(39 subjects)or funny(35 subjects)video with a length of 99 seconds,and fill out the self-assessment scale to examine the emotional states and adopt fNIRS equipment to detect hemodynamic changes when viewing the video.The results revealed that the funny video significant lower in satisfaction and desire dimension than the food video,and significant higher in funny dimension.Analysis of hemodynamic data revealed that funny video evoked significant great hemodynamic response in the frontopolar area,dorsolateral prefrontal than the food video.A total of 36 obese subjects were enrolled in the second study.This study asked the subjects to watch a low approach-motivated video(20 subjects)or a high approach-motivated video(16 subjects)with a length of 99 seconds.The study was conducted to investigate the effect of approach-motivated positive affect on the "cold" executive function,and the fNIRS technique was adopt to detect brain activation levels in the prefrontal region.Both the behavioral results and the hemodynamic results showed significant Stroop effects.In addition,we found that subjects who watched low approach-motivated video had significantly great hemodynamic response in the frontopolar area,ventrolateral,dorsolateral and orbitofrontal cortex than those who watched high approach-motivated video.A total of 38 obese subjects were enrolled in the third study.This study asked the subjects to watch a low approach-motivated video(19 subjects)or a high approach-motivated video(19 subjects)with a length of 99 seconds.The study was conducted to investigate the effect of approach-motivated positive affect on the "hot" executive function,and the fNIRS technique was adopt to detect brain activation levels in the prefrontal region.We found that the subjects who watched the high approach-motivated video had significantly higher probability of choosing immediate satisfaction than the low approach-motivated video viewer while completing the delayed discount task,and the hemodynamic response of the orbital frontal cortex was significantly lower than that of the low approach-motivated video viewer.Obese young adults were involved in the present study to examine the relationship between positive affect and executive function,and revealed a significant lower activation in executive function-related prefrontal cortex.Besides,fNIRS is a reliable instrument to monitor the hemodynamic response to the emotional stimuli and cognition task in obese young adults.