The Deficit Of Developmental Coordination Disorder On Executive Function And Its Neural Mechanism

Executive function(EF)refers to a series of complex higher cognitive functions used by individuals when completing goal-oriented tasks.Based on the different situations under the problemsolving framework,EF can be divided into "cold" EF and "hot" EF(Zelazo & Muller,2002).The research on "cold" EF mainly focuses on pure cognitive activities in the process of problem solving.Common tasks include inhibitory control,cognitive flexibility,working memory;while the "hot" EF can be regarded as the psychological function that involves significant emotions or motivations,such as risk decision-making,delayed gratification.In the process of individual learning,both "cold" and "hot" EFs play important roles,which are related to students’ external behaviors(O ’Toole et al.,2019;Wilson et al.,2018),mental health(Chavez-Arana et al.,2018;Zelazo,2020)and even future achievements(Mischel et al.,1988).Therefore,the exploration of the development trend of "cold" and "hot" EF and its influencing factors is the topic that researchers pay common attention to.At the same time,researchers have begun to further explore the neural mechanisms underlying EF development.Previous studies have found that children may not be as efficient as adults in completing EF tasks,with activation patterns in multiple brain regions including the frontal lobe and parietal lobe.With age,the core brain regions associated with a task of EF gradually become more precise in their response to this task through neural pruning,myelination,dendrites thickening,and increased integration with other brain regions,enabling individuals to perform tasks of EF with precise coding,thus becoming more efficient(Luna & Sweeny,2004;Wijeakumar et al.,2017).Therefore,some neurodevelopmental disorders may interfere with the normal development of EF.Developmental coordination disorder(DCD)is a very common one.Previous studies have shown that compared with children with normal development(TD),children with DCD tend to perform poorly in EF tasks(Asonitou & Koutsouki,2016;Asonitou et al.,2012;Maleki & Zarei,2016;Wilson et al.,2013).Wilson et al.(2013)compared 2,797 children with DCD and 3,407 children with TD through a meta-analysis,and found that the "cold" EF impairment of DCD involved three aspects: working memory,switching and inhibitory control.Studies on intervention also provide indirect evidence for the impairment of "hot" EF in DCD(Livesey et al.,2006),in which rich physical activities combined with teaching courses can help improve children’s "hot" EF(Homer et al.,2019).Recent brain imaging data also support an important link between the two domains of motor and EF,with important brain regions including the cerebellum,dorsolateral prefrontal cortex and its connective structures often showing common activation patterns during motor and cognitive tasks(Hanakawa,2011).Resting state f MRI data in children and adolescents indicate that the strength of functional connections in the brain is closely related to children’s EF performance,especially in the prefrontal and temporal regions,as well as the pathways between the striatum and the visual cortex.However,this study did not find any difference between DCD and TD in f MRI’s resting state functional connectivity(Rohr et al.,2023).The above studies reveal the executive work injury and its neural mechanism of some DCD.But these studies are still flawed in three ways.First,current studies on DCD and EF mainly focus on "cold" EF,namely,working memory,inhibitory control,cognitive flexibility,etc.,while "hot" EF has received less attention.Secondly,there are few studies on preschool children,most of which only focus on school age or adult age.Third,in previous neuroimaging studies,no researchers have used connectomic analysis to explore the relationship between motor coordination,cortical area of largescale brain functional network,and EF.This study aims to explore the "cold" and "hot" EF impairment in preschool children with DCD,and further explore its potential neural mechanism through structural state NMR data combined with regulatory effect analysis.In study 1,126 children aged 3-6 were recruited from children’s hospitals in two places.Children were divided into DCD and TD using the second version of the Children’s Motor Coordination Assessment Scale(MABC).The flanker task,the DCCS task and the customized sequence indicated that the task measured the inhibitory control,cognitive flexibility and working memory of children’s "cold" EF,respectively.The results found that children with DCD had significantly worse inhibitory control and cognitive flexibility than those with TD,but working memory may not be impaired.In study 2,children were also divided into DCD and TD by MABC,and the inhibitory impulse selection and inhibitory maintenance of "hot" EF of preschoolers were measured by children’s gambling task,cake gambling task and intertemporal decision task,respectively.The results showed that the ability to inhibit impulse selection was significantly better in DCD children than in TD children,but the ability to maintain inhibition may not be impaired.In Study 3,exploratory factor analysis and magnetic resonance imaging techniques were used to first reduce the dimension of variables and extract common factors including inhibitory control and cognitive flexibility as the score index of preschool children’s "cold" EF.Secondly,the area of the ventral attention network was selected as the independent variable,the "cold" EF as the dependent variable,and the motor coordination as the moderating variable,and the adjustment model was established.The results showed that the ventral attention network cortical thickness of the brain affected the "cold" EF,and this relationship was modulated by motor coordination.The conclusions of this study are as follows:(1)The inhibitory control and cognitive flexibility of preschool DCD children are significantly worse than that of normal children,while the working memory is no different from that of normal children.(2)Preschoolers with DCD showed significantly better ability to inhibit impulsive choice than normal children,but delayed gratification showed no difference with normal children.(3)The ventral attention network cortical thickness significantly predicted "cold" EF,and motor coordination played a moderating role in this predictive relationship.