Executive Functions In Preschool Children With ADHD And DBD

Attention deficit hyperactivity disorder(ADHD)and disruptive behavior disorders(DBD)are two kinds of children's externalizing behavior problems,mainly as a model of group psychological barriers with attention deficit and hyperactivity,violation of social rules and produce destructive behavior as the main feature of the implementation the function of the defect or damage is usually considered the etiological factors of ADHD and DBD.Executive Function(EF)is a kind of complex cognitive structure,which is the process of conscious control of thought and action.According to the essence and connotation of executive function,some researchers think that executive function is a kind of advanced cognitive mechanism or ability,and the implementation of the function is divided into inhibitory control and working memory,inhibition control refers to the conscious control of self or advantage and reaction,does not meet the current need to control the ability to inhibit or not appropriate behavior,mainly for the violent reaction of delaying or withholding,and make appropriate choices and reactions;working memory refers to keep the information and processing of the information in consciousness,to guide the subsequent actions or decisions.In addition,due to the complexity of the executive function of cognitive process,cognitive complexity and control theory according to the processing process in the implementation of emotional involvement will be divided into EF with the orbital and medial prefrontal cortex area(OMPFC)linked to the "hot" executive function(hot EF)and dorsolateral prefrontal cortex the cortex(DLPFC)linked to the "cold"executive function(cool EF).The cold executive function is caused by the relatively abstract and contextualized problems,while the thermal executive function is indispensable to solve the problems involved in the processing of emotion and motivation.Executive function development theory that 3?5 years old is the first critical period of the development of executive function of children,and children with externalizing behavior problems exist in this stage of EF development obstacles.In this longitudinal study,we examined the stability of the association between executive functions and externalizing behavior problems,and the developmental change of executive functions in a predominately clinically diagnosed preschool sample(N= 88).Inhibition?working memory."cool" and "hot" executive functions performance were assessed three times in 24 months.Across time,poorer inhibition performance in young children was associated with attention deficit hyperactivity disorder(ADHD)and disruptive behavior disorders(DBD),and poorer working memory performance was associated with ADHD and DBD.In the other wise,poorer "cool" executive functions(EF)performance in young children was associated with ADHD and DBD,and poorer "hot" EF performance was associated with ADHD.The improvement of inhibition and "hot" EF performance was more pronounced in the clinically diagnosed children compared to the TD children.Inhibition and working memory performance increased over time,especially in the early preschool period.This is very similar with "cool" and"hot" EF developmental model.However,the development trend of each function sub factor is different.The development of inhibitory control and "hot" executive function was mainly at the age of 3?4,working memory and "cool" executive function performance was significantly increased at the age of 3-5.On the whole development curve,inflection point in the development of executive function is 4 years old.