Neural Mechanisms Of Inhibitory Control Of Aging In Multiple Conflict Situations

At present,China is already in an aging society and the degree of aging is showing a rapid progress trend.In the future,considering the reality that the life expectancy is increasing and the fertility rate is still low,the degree of aging in China will further deepen.The aging of the population is not only accompanied by many problems such as medical care,pension,family and social economic burden,but also means the loss of working ability and even independent living ability of the elderly.Previous studies have shown that even in healthy elderly groups,a series of important cognitive functions such as working memory,inhibitory control,cognitive flexibility,induction and reasoning show systematic impairment due to aging,and ultimately reduce quality of life and overall well-being.Cognitive decline in older adults has attracted increasing attention,and aging is associated with multiple domains of cognitive function,of which inhibitory control is a central component.Inhibitory control is the ability to suppress automatic,goal-irrelevant information or impulses.Notably,previous research on inhibitory control of aging has focused on the issue of a single conflict control mechanism.However,in real-life situations,one usually encounters complex situations where multiple conflicts from different sources occur simultaneously.Multiple source interference task(MSIT)can satisfy the requirement of multiple conflicts by integrating the cognitive conflicts from Stroop,Flanker and Simon tasks.Previous studies on MSIT have focused on patients suffering from neuropsychiatric disorders,while the neural mechanisms behind the inhibition of multiple conflicts controlling aging in normal older adults remain unclear.Therefore,in the present study,MSIT was used to detect the decline of multiple sources of interference associated with aging.Given the paucity of previous research on inhibitory control of aging in multiple conflict situations,Study 1 will explore the mechanisms of inhibitory control of multiple conflict at the behavioral and activation levels.We used functional magnetic resonance imaging(f MRI)to analyze activation in older and younger adults during the MSIT task and to explore the mechanisms of inhibitory control in multiple conflict situations in older and younger adults by analyzing the activity patterns of brain regions under the condition of the multiple-source interference.Study 1 explored the inhibitory control mechanisms of young and old people in multiple conflict situations by looking at the behavioral and activation levels.First,at the behavioral level,we found that older adults were more responsive to multiple conflict situations compared to younger adults.Second,at the activation level,we found that both older and younger adults activated the anterior cingulate gyrus(ACC),supplementary motor area(SMA),dorsolateral prefrontal cortex(dl PFC),and inferior frontal gyrus(IFG),inferior parietal lobule(IPL),and inferior occipital gyrus(IOG)in the multi-source interference condition compared to the congruent condition.According to conflict monitory theory and attentional control theory,the activation of these brain regions suggests that when faced with multiple conflicts,the ACC monitors conflict signals and sends monitored conflict signals to other brain regions,the activation of the dl PFC suggests that it compensates for the lack of attentional resources under more difficult task conditions,thereby increasing top-down attentional control resources,the IOG is modulated by the dl PFC to enhance task-related processing of information,IFG by inhibiting the processing of task-irrelevant information,while SMA achieves inhibitory control of multiple conflicts through motor control.At the activation level I observed the compensation-related utilization of neural circuits hypothesis(CRUNCH)phenomenon of neural circuits,in which older and younger adults have similar activation under multiple sources of interference but poorer behavioral performance than younger adults,suggesting that the role of these brain regions is the same in older and younger adults,but that older adults may have impaired function.Study 2 We used g PPI analysis to explore changes in functional connectivity in MSIT in older and younger adults transitioning from consistent to multi-source interference conditions.The results of the meta-analysis were chosen as the region of interest(ROI).In older adults,the results showed reduced intra-network connectivity in the FPN and SMN,as well as reduced inter-network connectivity in the right ACCFPN and right ACC-SMN.Between-group results showed reduced right-ACC-PFN and right-ACC-SMN connectivity in older adults compared to younger adults.Furthermore,the correlation and moderation effect results illustrate that older adults with higher connectivity associated with the right-sided ACC will have better task performance.Our results suggest that the failure of neural recruitment strategies for ACC-related connectivity in older adults under harder task conditions is similar to that described by the CRUNCH phenomenon,indicating impaired ACC conflict monitoring with aging.The significance of this paper is to provide evidence for mechanisms of inhibitory control in multiple conflict situations at the behavioral,activation,and functional connectivity levels of brain networks.This paper extends the CRUNCH theory from the activation level to the brain network connectivity level and complements the neural mechanisms of aging-related inhibitory control with a multiple source interference task(MSIT)with functional connectivity at the brain network level and reveals that the ACC plays a key nodal role in inhibitory control and that the conflict monitoring of the ACC is impaired with aging.